SUMMER 2018 · 2018. 6. 15. · 31 Detecting leaks in larger tanks Alexander Bukhman, Gauging...

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SUMMER 2018

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Hydrocarbon Engineering

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CONTENTS

ONTHE FRONT COVER

Summer 2018 Volume 04 Number 02 ISSN 1468-9340

03 Comment05 World News10 Rough seas ahead

Gordon Cope, Contributing Editor, explores the changes that are rocking global energy markets and how they are having a knock-on effect in Europe.

16 Comparing apples to applesBrian Thompson and Aaron Clarke, Matrix Applied Technologies, USA, explain why it is important to eliminate surprises when selecting a geodesic aluminium dome roof.

21 To dome or not to dome?Michael Sprung, EnviroEye LLC, USA, examines roofs and storm water management practices relating to aboveground storage tanks.

25 Testing seal suitabilityDaniel C. Gray, Petrex Inc., USA, examines the importance of perimeter sealing systems for fl oating roofs through an examination of four elastomeric wiper seal materials.

31 Detecting leaks in larger tanksAlexander Bukhman, Gauging Systems Inc., USA, compares leak detection methods for aboveground storage tanks.

35 Finding the right balanceBart Wauterickx and Bas Hermans, The Sniffers, Belgium, explain how a combination of measurement techniques can help ensure a complete leak detection survey.

39 New horizonsRoman Filatov, Transneft Diascan JSC, outlines the benefi ts of tank diagnostics methods that do not require decommissioning.

Known for precision engineering and unmatched quality, and recognised for excellence in environmentally protective technology, Matrix Applied Technologies, a subsidiary of Matrix Service Company, provides proven, cost-effective products for the aboveground storage as well as process and API heater markets worldwide.

43 Improving inspection effi ciencyEdwin Van Der Leden, Neil Randal Pearson and Damian Gallagher, Eddyfi , UK, outline methods to help improve storage tank inspection effi ciency.

47 The never-ending quest for safetyAs legislation and regulations are tightened, the quest for increased safety and effi ciency, built into tank cleaning systems, never stops. Søren Hansen, Oreco A/S, Denmark, explains why.

51 A fl ying startDerek Blagg, Varec Inc., USA, discusses best practices for automation at airport fuel farms.

55 Embracing Industry 4.0Tomi Lahti, Lauri Saurus and Niko Hellgren, NAPCON, Finland, report on how Industry 4.0 is driving effi ciency and security improvements in tank and terminal operations.

59 Working wirelesslyVance Ray, R3 Automation, USA, explains how wireless sensing helps producers and facilities cut emissions and comply with tough regulations.

63 Crossed signalsScott Keller, SignalFire Wireless Telemetry, USA, examines how self-confi guring mesh networks address the challenges associated with the wireless monitoring of outdoor tank level applications.

65 Making a pointJeremy M. Lucas, Mangan Software Solutions, USA, discusses the development and implementation of safety lifecycle management point-to-point testing in the Cloud for midstream oil and gas origination, tank storage, and delivery terminals.

68 Paving the path to a cleaner futureMiriam Wennberg, Connect LNG AS, Norway, in collaboration with Gas Natural Fenosa, Spain, introduces a transfer solution that can help to make LNG accessible to a number of locations where it was previously not deemed feasible.

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APPLICABLE ONLY TO USA & CANADAHydrocarbon Engineering (ISSN No: 1468-9340, USPS No: 020-998) is published monthly by Palladian Publications Ltd GBR and distributed in the USA by Asendia USA, 17B S Middlesex Ave, Monroe NJ 08831. Periodicals postage paid New Brunswick, NJ and additional mailing offi ces. POSTMASTER: send address changes to HYDROCARBON ENGINEERING, 701C Ashland Ave, Folcroft PA 19032

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CONTRIBUTING EDITORSNancy Yamaguchi Gordon Cope

If you were one of the many millions who tuned in to watch the Royal wedding of Prince Harry and Meghan Markle, you may be forgiven for thinking that the UK regularly bathes in beautiful spring sunshine. Thankfully

for the happy couple – and the thousands of well-wishers who lined the streets of Windsor

to catch a glimpse of the new Duke and Duchess of Sussex – the weather was just about as perfect as it ever gets in the UK in mid-May.

In the week leading up to the wedding, the British media became preoccupied with one of its favourite pastimes: predicting the weather. National newspapers analysed Met Offi ce statistics for the last 86 years to predict a 23% chance of rain in the south-east of England on the big day, while warning that there had been heavy downpours on 19 May back in 2015 and more rainfall in 2016. You see, the only predictable thing about the British weather is its unpredictability.

But us Brits are not the only weather watchers. In the last couple of months, experts have been releasing their predictions for the upcoming Atlantic storm season, with interest understandably high after the devastating impact of Hurricanes Harvey and Irma in 2017. At the start of April, Colorado State University (CSU) hurricane researchers predicted a slightly above-average Atlantic hurricane season this year, citing the relatively low likelihood of a signifi cant El Niño as a primary factor.1 The CSU Tropical Meteorology Project team is predicting 14 named storms during the season, of which seven are forecast to become hurricanes and three are expected to become major hurricane strength. At the time of writing, the team is predicting that 2018 hurricane activity will be approximately 135% of the average season (by comparison, last year’s hurricane activity stood at about 245%). A forecast update was due to be released at the end of May.

Meanwhile, Dominick Chirichella, DTN Risk Management and Advisory Services Director, is predicting an average hurricane season, entailing between six to eight storms.2 However, Chirichella warns that this does not necessarily mean the oil market will continue at status quo, as it only takes one of these storms to disrupt the economy. He notes that even a less severe storm could result in surging prices and economic disruption, as US oil inventories are below the fi ve-year average: “Inventory will be under close watch this hurricane season, as unplanned shut-downs could force a halt in production, leading to price spikes.” Chirichella also believes that any disruption would have implications worldwide, as the US has become a global player in the market: “This means that a single storm in the US can affect the global market in a very different way than it did previously. Impacts could include unexpected lack of inventory, delayed exports, or price spikes that deter domestic purchases and encourage an increase in exports.”

While it can be diffi cult to accurately predict what mother nature has in store for us, here’s hoping that she is much kinder during this year’s storm season.

1. ‘Slightly above-average 2018 Atlantic hurricane season predicted by CSU team’, Colorado State University, (5 April 2018), https://source.colostate.edu/slightly-above-average-2018-atlantic-hurricane-season-predicted-by-csu-team/

2. CHIRICHELLA, D., ‘DTN Provides Oil & Gas Market Outlook for Upcoming Storm Season’, (3 May 2018), https://www.dtn.com/free-resources/blog/dtn-provides-oil-gas-market-outlook-upcoming-storm-season/

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WORLD NEWS

Summer 20185

Mexico | Valero signs agreements to supply refined products

Valero Marketing and Supply de Mexico S.A. de C.V., an indirect

wholly owned subsidiary of Valero Energy Corp., has signed long-term agreements to directly supply refi ned products into northern Mexico from its Corpus Christi and Three Rivers, Texas, refi neries via a pipeline and terminal expansion in Nuevo Laredo. The company expects to begin delivering products through this expanded facility by the end of the year.

In August 2017, Valero announced a long-term agreement with IEnova to import refi ned products at the new

Port of Veracruz and distribute into central Mexico. IEnova won the Port of Veracruz’s bid for a 20-year concession to build and operate a new terminal with 1.4 million bbls of storage capacity, which has since expanded to 2.1 million bbls. In addition, IEnova is building two inland storage terminals strategically located near Puebla and Mexico City that will be supplied by rail. Valero has exclusive use of all three terminals.

IEnova expects the Veracruz terminal to start operations by the end of 2Q19, with the inland terminals coming online in 3Q19.

USA | Matrix Service awarded crude oil storage and loading contract

Matrix Service Company’s subsidiary, Matrix Service Inc.,

has entered into a full engineering, procurement, and construction (EPC) contract with a large independent oil company for the expansion of crude oil storage and loading capabilities on the Texas Gulf Coast.

Matrix PDM Engineering, which performed the front-end engineering design (FEED) work for the project, will complete the detailed design engineering. This award follows an earlier award by the customer for marine loading upgrades to accommodate very large crude carriers (VLCC).

“With growing global demand for crude oil and other petroleum products comes the need for related infrastructure, especially along the Texas Gulf Coast,” said Matrix Service Company’s President and CEO, John R. Hewitt. “As a long-standing leader in the EPC and maintenance of crude oil and other storage terminals, along with our recently added engineering expertise in marine structures, Matrix is well positioned to help our clients achieve their business objectives.”

Finland | Hamina LNG terminal receives building permits

Wärtsilä has announced that the LNG terminal that it is to

build under a turnkey contract at the port of Hamina has reached financial close and received the necessary building permits.

Debt financing for the project has been concluded with Skandinaviska Enskilda Banken and Finnvera. The total investment is worth approximately €100 million.

In addition to supplying the engineering, procurement and construction of the terminal, Wärtsilä is joining the project through a minority investment by Wärtsilä Development and Financial Services (WDFS) in Hamina LNG Oy. The main shareholders are Hamina Energy Ltd and Alexela.

The building permit for the LNG terminal has also been

secured. In the first stage, a 30 000 m3 LNG storage tank will be built. Facilities are also being prepared for a second 20 000 m3 storage tank to be added at a later date. The earthwork has been completed on schedule and construction work has already commenced. The LNG terminal is anticipated to become fully operational in 2020.

USA| Keyera develops storage and blending terminal

Keyera Corp. has announced the development of a crude oil

storage and blending terminal in Cushing, Oklahoma. The Wildhorse Terminal will include 12 aboveground tanks with 4.5 million bbls of working storage capacity. The majority of the capacity is backed by fee-for-service, take-or-pay storage arrangements, ranging from two to six years in length.

Wildhorse will initially be connected by pipeline to two existing storage terminals in Cushing. These connections will provide customers with access to the majority of the

crude oil streams on several major pipeline networks. Keyera’s US subsidiary, Keyera Energy Inc., will oversee construction and operate the Wildhorse terminal once it is in service, which is expected by mid-2020. Matrix Service Inc. has been awarded the engineering, procurement, fabrication and construction contract for the project.

An affi liate of Lama Energy Group (LEG) will own 10% of the project, with the option to increase its ownership to up to 30% by the end of 2018.

WORLD NEWSIN BRIEF

6Summer 2018 6

France | Fos Cavaou LNG terminal prepares for LNG bunkering

E lengy and its subsidiary, Fosmax LNG, have announced

plans to adapt the Fos Cavaou LNG terminal to offer a new LNG bunker-vessel loading service.

This service will enable the terminal to accommodate smaller vessels (capacity less than 20 000 m3) which, after loading their LNG tanks at Fos Cavaou, will be able to supply ships in the port of Marseille-Fos and other sites in the Mediterranean sea.

This new service primarily calls for work to modify the wharf at the Fos Cavaou LNG terminal, which will be completed in June 2019. It enriches the offer of the Fos-sur-Mer LNG terminals, which already accommodate the unloading of LNG carriers ranging from 20 000 m3 to 265 000 m3 (Q-Max type extra large LNG tankers).

Elengy and Fosmax LNG estimate that the Fos Cavaou terminal will be able to accommodate around 50 micro-tankers per year.

CB&I has been awarded a contract, valued at nearly US$35 million, by a leading Canadian infrastructure company for the engineering, procurement, fabrication and construction of three LPG spheres.

H-Energy Gateway Private Ltd (the energy venture of Hiranandani Group) has announced the launch of India’s first floating storage regasification unit (FSRU) based LNG terminal at JSW Jaigarh Port in Ratnagiri District, Maharashtra. The Jaigarh Port is owned and operated by JSW Infrastructure (the maritime infrastructure development arm of JSW Group).

Mech-Tool Engineering Ltd has signed a contract with a leading air filtration company to deliver its blast relief systems on what will be the UK’s largest onshore gas storage facility. Located in Cheshire, the Stublach Gas Storage facility is the biggest salt cavern storage project in the country. The facility stores natural gas 500 m below the surface until customers require it. With 450 million m3 of gas stored at Stublach, the facility has enough gas stored to power 270 000 homes for both cooking and heating for more than 12 months.

Buckeye Partners L.P. has announced that it is expanding the Chicago Complex, its key logistics hub in the Midwest, at a cost of approximately US$80 million. This project, which is backed by a long-term agreement with BP Products North America Inc., will further expand storage, component blending, throughput capacity and service capabilities in the Chicago Complex to support the growing needs of this customer.

India | TMC supplies compressors for FSRU

TMC Compressors of the Seas (TMC) has signed two contracts

to supply a total of fi ve marine compressors to a fl oating storage regasifaction unit (FSRU) that Hyundai Heavy Industries (HHI) is building for Swan Energy Ltd.

The company has signed a contract directly with HHI to provide three service and control air compressors to the shipyard. The compressors will be delivered in 3Q18.

The company has also signed a subcontractor deal with another supplier to provide two feed air compressors to a nitrogen system

delivery to the FSRU. This compressor delivery will be made in July 2018.

The FSRU that HHI is building will have a storage capacity of 180 000 m3 with an ultimate gas send out rate of 1000 million ft3/d. The FSRU will be used at Swan Energy’s LNG import terminal in Jafrabad, Gujarat. Once completed, the FSRU will be moored to a fi xed jetty and will regasify imported LNG to enable distribution by pipeline grid and road tanker.

The terminal, with the capacity to handle 5 million tpy of LNG, is being set up by Swan LNG Pvt. Ltd.

The Netherlands | Gate terminal reaches milestone

In a fi rst for the terminal, Gate recently loaded two small LNG

carriers at the same time.The Cardissa LNG bunkering

vessel was at the dedicated small scale jetty, while the ice-class Coral Energice was loaded at Jetty 1, one of the two jetties that can handle both small and large scale LNG carriers.

A record daily number of 12 LNG trailers/containers were loaded simultaneously.

Gate has seen a steady increase in its small-scale LNG activities since the dedicated third small-scale LNG jetty became operational in 2016, along with the additional two automated LNG truckloading bays in 2017.

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8Summer 2018 8

USA | HEP terminal commences operations

Howard Midstream Energy Partners LLC (HEP), along with its bulk

liquid terminal subsidiary, Maverick Terminals Corpus LLC, has completed its new bulk liquid terminal facility in the Port of Corpus Christi. Operations have commenced, including the storage, blending, and unit-train loading of two grades of gasoline – ultra-low sulfur diesel (ULSD) and gasoline blend stocks from various local refi neries – for ultimate delivery to global markets.

The new terminal facility consists of six 80 000 bbl tanks with an aggregate storage capacity of 480 000 bbls. The facility is

permitted for up to 1.25 million bbls of storage, with the capability to expand up to 2.5 million bbls. Products can be received by marine vessels and via a 12 in. pipeline, owned by HEP, which is connected to Origin Station, providing direct connectivity to all six refi neries in Corpus Christi.

HEP has also entered into an agreement with the Port of Corpus Christi to engineer and build Dock 20, which is being designed to accommodate Suezmax-class vessels for the movement of a variety of bulk petroleum liquids at transfer rates of up to 50 000 bbls/hr.

DIARY DATES11 - 13 June 2018ILTA International Operating Conference & Trade ShowHouston, Texas, USAwww.ilta.org/AOCTS

25 - 29 June 2018World Gas ConferenceWashington D.C., USAwww.wgc2018.com

12 - 13 September 201811th Annual National Aboveground Storage Tank Conference & Trade ShowGalveston, Texas, USAwww.nistm.org

17 - 20 September 2018Gastech 2018Barcelona, Spainwww.gastechevent.com

18 - 20 September 2018Turbomachinery & Pump SymposiaHouston, Texas, USAtps.tamu.edu

26 - 27 September 2018Tank Storage AsiaSingaporewww.tankstorageasia.com

27 September 2018Tank Storage Conference & ExhibitionCoventry, UKwww.tankstorage.org.uk

01 - 03 October 2018AFPM Operations & Process Technology SummitAtlanta, Georgia, USAwww.afpm.org/conferences

05 - 06 December 2018Tank Storage GermanyHamburg, Germanywww.tankstoragegermany.com

17 - 19 March 2018AFPM Annual MeetingSan Antonio, Texas, USAwww.afpm.org/conferences

USA | JV to develop crude oil terminal

Buckeye Partners L.P. has formed a joint venture with Phillips 66

Partners LP and Andeavor to develop a new deepwater, open access marine terminal in Ingleside, Texas. The South Texas Gateway Terminal will be constructed at the mouth of Corpus Christi Bay. The facility is positioned to serve as a primary outlet for crude oil and condensate volumes delivered off of the planned Gray Oak pipeline from the Permian Basin.

The terminal, to be constructed and operated by Buckeye, will offer 3.4 million bbls of crude oil storage capacity, connectivity to the

Gray Oak pipeline and two deepwater vessel docks capable of berthing very large crude carrier petroleum tankers as part of the initial scope of construction. The facility could be expanded to include over 10 million bbls of storage capacity, as well as additional docks and other inbound pipeline connections.

The initial construction of the terminal is supported by long-term minimum volume throughput commitments from customers, including Phillips 66 and Andeavor, and is scheduled to commence initial operations by the end of 2019.

Bangladesh | Exmar and Gunvor sign FSRU agreement

Exmar has executed a fully effective 10-year charter with Gunvor for

the provision of its fl oating storage and regasifi cation unit (FSRU) barge and related services.

The FSRU barge is currently at Keppel Shipyard undergoing site-specifi c modifi cations after being

delivered from Wison Offshore and Marine in December 2017. It is expected to arrive in Bangladesh in 4Q18 and start operations after its full commissioning.

At present, the FSRU has been fully paid by Exmar and the fi nancing of the unit is under discussion.

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Summer 2018 10

Summer 2018111

Europe is one of the largest markets for fuels and petrochemicals; storage and terminals play a vital role in keeping the market functional and versatile. It is also one of the most complex markets, with major global infl uences

playing out within its confi nes.

RefineriesThe majority of crude, fuel and liquid chemical storage in Europe is associated with refi neries, and the fortunes of the former are intricately intertwined with the latter.

The growth of US shale oil production is having an impact in Europe. Refi neries on the US Gulf Coast (USGC) are designed to process heavier crudes from Mexico, Venezuela and Canada; the light crude produced in the Permian basin is more suited to Asian and European refi neries. In 2016, the US exported 35 million bbls to Europe; in 2017, exports more than doubled to 75 million bbls.

Wood Mackenzie predicts that the US will add further a 4 million bpd production between now and 2023. USGC refi neries can absorb approximately 25% of that, leaving another 3 million bpd for export, or approximately 1 billion bbls/yr. Wood Mackenzie predicts that most of the extra crude will end up in Europe, displacing Asian and African supplies.

With regards to fuels, strong growth in demand in the US in 2016 and 2017 led to the import of European gasoline and diesel to the East Coast. These imports reached 400 000 bpd during the peak summer driving months. Since then, US consumer demand has decreased by 3%. Concurrently, US production of fuels has reached record volumes, displacing European supplies;

Gordon Cope, Contributing Editor, explores the changes that are rocking global energy markets and how they are having a knock-on effect in Europe.

12Summer 2018

exports of European gasoline and diesel to the US have dropped by roughly 35% to 240 000 bpd. Demand in Latin America is still strong, but that market is being fi lled by USGC refi ners; the US exported 1.2 million bpd of gasoline and diesel to the region, primarily to Mexico. “European refi ners are the world’s marginal producers,” noted a prominent refi ning analyst. “If US gasoline demand is not as strong as we think it is, European refi neries will feel the pain fi rst.”

Refi ners in Europe are adjusting to evolving circumstances. The Amsterdam, Rotterdam and Antwerp (ARA) region has approximately 2.1 million bpd refi ning capacity. It also has the largest accumulation of storage capacity in Europe. According to studies carried out by Erasmus University of Rotterdam (EUR), the port region has 42.5 million m3 (270 million bbls) of storage for crude, refi ned liquids and liquid chemical products (in comparison, the Cushing, Oklahoma, US, region, a central pipeline transportation hub for North America, has 90 million bbls, mostly crude).

Rotterdam has the largest portion of storage with almost 27 million m3 (162 million bbls); of that, around 49% is crude, 49% is refi ned products, and the rest is liquid chemicals. Signifi cantly, refi neries operate 94% of the crude storage capacity, and slightly under half the fi nished products.

ExxonMobil has initiated a €840 million expansion of its Esso Nederland BV refi nery in Rotterdam. The expansion will not increase overall capacity of 191 000 bpd, but will augment production of ultra-low sulfur fuels. The expansion will also add 140 000 m3 of storage capacity.

Others are seeking to leave the ARA region market. In 2016, Koch Supply and Trading decided to sell its 85 000 bpd refi nery in Rotterdam. Vitol, an energy company based in Rotterdam, purchased the facility in 2017; the company currently trades over 7 million bpd of crude oil and products and possesses 16 million m3 of storage worldwide.

In France, Total operates over 800 000 bpd refining capacity. In 2016, the company earmarked €200 million to transform its 150 000 bpd La Mede refinery in Châteauneuf-les-Martigues, France. The facility (which is situated 15 km northwest of Marseille), will produce 500 000 tpy of biodiesel, made primarily from used vegetable oils. The decision was based on an EU directive to have 10% of renewables in transportation fuels by 2020, and also due to heavy financial losses. The company is also establishing a logistics and storage hub, converting former gasoline and diesel tanks to handle biofuel.

Total is also looking to expand on its refi nery and petrochemical ventures abroad. In April 2018, it signed an agreement with Saudi Aramco to expand its JV in the Saudi Arabia Total Refi ning and Petrochemical (SATORP) complex in Jubail (62.5% owned by Saudi Aramco and 37.5% owned by Total). The refi nery currently produces 400 000 bpd of fuel and 700 000 tpy of paraxylene, 140 000 tpy of benzene and 200 000 tpy of polymer-grade propylene. Details of the new agreement have not been released, although both parties have expressed interest in

expanding capacity at one of the world’s most technically-advanced facilities by more than 10%.

In the UK, refi ning and petrochemical spending is a combination of modest capacity increases, maintenance, and upgrading of infrastructure. Essar Oil UK’s Stanlow refi nery is currently undergoing a planned turnaround, part of which is also an upgrade aimed at increasing processing capacity from 185 000 bpd to 205 000 bpd. The work was completed in April 2018.

ExxonMobil is seeking to modernise its fuel transportation and storage facilities between Fawley refi nery and its West London Terminal (WLT) storage in Hounslow, near Heathrow airport. The 105 km, 30 cm pipe is over 50 years old and approaching obsolescence; the new line would keep the equivalent of 100 tankers off the roads each day. The WLT, which distributes diesel, various petrol grades and jet fuel, has 17 tanks onsite with over 100 000 m3 (600 000 bbls) capacity.

CF Fertilizers is spending £40 million to upgrade its Billingham plant in the UK. Over £15 million of that budget will be spent to upgrade the ammonia reforming plant, extending its life by 20 years. Another £8 million will upgrade the acid facilities. In addition to the Billingham plant in Teesside, CF also operates the Ince facility in northwestern England. The two facilities have a combined capacity of 800 000 tpy of ammonia, and 1.1 million short t of ammonium nitrate (AN).

Natural gas changesTwo new LNG facilities in the US have boosted the country’s export capacity to approximately 3.6 billion ft3/d. Although most is going to Asia, Europe received an average of 250 million ft3/d of LNG in 2017, primarily to Spain, Turkey and Portugal. According to the US Energy Information Administration (EIA), several new trains are expected to come online within the next two years, raising total US export capacity to almost 10 billion ft3/d by the end of 2019. Much of the increased production is expected to enter the European market due to competitive pricing and a desire to diversify away from Russian supplies.

The latter factor, especially, is likely to spur LNG imports into Europe. The continent is already massively supplied with LNG regasifi cation infrastructure. Spain, for instance, has 49 million tpy regasifi cation capacity and the UK has 35 million tpy; both operated at slightly over 21% capacity in 2017.

Germany, however, has no LNG regasifi cation facility, something that the federal government is keen to rectify. The country’s association of transmission operators, FNB GAS, has included in its 10 year plan a new LNG terminal in Brunsbüttel, Germany. The €500 million plant would be in operation in late 2022. REW AG, a German utility, is also developing an LNG facility on the Rhine River at Duisburg. The €500 million project will supply the heart of the country’s heavy industry sector.

Gazprom and its supporters in Germany have initiated plans to build the Nord Stream 2 pipeline. The €8.4 billion project will twin the Nord Stream 1 pipeline system that runs for 1225 km under the Baltic Sea from Russia to

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14Summer 2018

Germany. It will deliver an additional 55 billion m3/yr to Europe, doubling the system’s capacity. The second line is planned to make landfall close to where the original line enters Europe, near Greifswald, Germany. Extensive terminal facilities already exist in Greifswald; the new line would require relatively minor additions.

However, the US and several European countries have expressed concerns that Nord Stream 2 will make Europe even more reliant on Russian gas. The project, which is 100% owned by Gazprom, does not comply with the EU’s third energy package rules that state that import pipelines cannot be owned by gas suppliers, and they must make capacity available to third-parties.

Regardless, there is a need to increase natural gas storage. Across Europe, storage capacity stands at 107 billion m3 (3.8 trillion ft3). Storage rates typically exceed 90% (in contrast, US underground gas storage capacity rarely exceeds 35%).

Sedimentary deposits in northern Germany include salt domes, which are ideal for creating underground gas storage. Wingas, a subsidiary of Gazprom, operates the 4.4 billion m3 (158 billion ft3) Rehden storage facility; Germany has a total of approximately 24 billion m3

(864 billion ft3) storage capacity. Gazprom also purchased an abandoned mine in

Waren, Germany, approximately 100 km southwest of Greifswald, where it is planning an underground gas storage facility with the capacity of 5 billion m3

(180 billion ft3). According to CEDIGAZ, there are 27 gas storage facilities under construction throughout Europe, adding an additional 8.4 billion m3 (302 billion ft3).

In addition to liquid fuels, Europe has signifi cant liquid petrochemical facilities. In early 2018, Yara International

opened the world’s largest AdBlue production plant in Brunsbüttel. AdBlue is a diesel exhaust fl uid made from natural gas; it reacts in a vehicle’s catalytic converter to remove harmful nitrous oxide emissions. The €28 million facility has a capacity of 1 million tpy. The facility required a new deep sea ship loading dock and a 110 000 bbl tank. Output will be used in Europe, as well as exported to the US.

The futureThere are several factors that will infl uence tanks and terminals in Europe in both the short term and longer term. The tremendous growth in shale gas in the US has, in addition to spurring on exports of LNG, revitalised the North American petrochemical industry. The latter uses natural gas for both feedstock and production, and the abundance of low-cost gas has resulted in over US$100 billion in greenfi eld plants and expansions of capacity. Europe has a signifi cant petrochemical industry, but competition from the US hinders expansion.

In 2020, new fuel specifi cation rules from the International Maritime Organization (IMO) come into effect. The maximum sulfur content in marine bunker fuels is mandated to drop from current levels of up to 3.5%, to no more than 0.5%. As bunker demand decreases, storage tanks will switch to holding gas oil for use as marine fuel.

Over the longer term, consumption of hydrocarbons is expected to decline. EU environmental policies will limit greenhouse gas emissions; in late 2016, Germany released its Climate Action Plan 2050, a framework to largely decarbonise its economy by the mid-century. In addition, vehicle fuel effi ciency will rise, and electric vehicles will displace fossil-fuel cars, buses and trucks. As consumption diminishes, European refi ners will face even more competition from the US and the Middle East, inevitably resulting in refi nery closures and a reduction in tank capacity.

European storage companies are looking worldwide for business opportunities. Vopak is the world’s largest independent storage company, having a total of 66 crude, fuel, natural gas, chemicals and vegetable-oil facilities worldwide, with a total capacity of over 35 million m3

(210 million bbls). The Rotterdam-based company has over 14 million m3 (84 million bbls) storage capacity in Europe (primarily in Antwerp and Rotterdam). It announced in its 2017 fi nancial report that it has budgeted new growth projects with a total capacity of 862 000 m3 (5 million bbls) in South Africa, Brazil, Canada and Malaysia.

ConclusionIn conclusion, storage and terminals are a vital component of Europe’s energy and petrochemical sectors, and will remain so for the foreseeable future. International factors (including the growth of US exports and new sources of gas from Russia), will collide with domestic factors (such as increased environmental directives and reduced consumption), to create challenges that impact the bottom line. So far, the companies that provide storage and terminal services in Europe have shown an excellent ability to innovate, adapt and thrive.

Cyber problems afootOver the last several years, the port of Rotterdam has been the victim of fraudulent activity, what the Port of Rotterdam Authority calls ‘storage spoofi ng’. The term encompasses the sale of nonexistent storage capacities and stocks of resources and materials. The targets have been national and multinational companies looking for storage facilities in the Rotterdam port.

In coordination with fi rms operating in the port, the port authority created FERM-Rotterdam, a cyber criminal task force. According to FERM, a spoof will be initiated by a fake site purporting to sell 1 or 2 million bbls of jet fuel. The fake sites often resemble the legitimate fi rms operating in the port, except that they offer much lower prices. They entice the buyer to make a down-payment by using fake stamps and certifi cates of ownership. When the buyer attempts to take ownership, however, they discover that the goods do not exist.

Although storage spoofi ng is not a major criminal activity (with approximately only six cases reported annually), FERM is aware that it is signifi cantly large enough to cause reputational damage to the port, and has instigated an anti-spoofi ng campaign that explains the fraud in detail and offers prevention details.

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Summer 2018171

Geodesic domes have been perfected by architects since the turn of the 20th Century, now standing as some of the most inspiring structures in the world. In the past 40 years, this iconic form has given rise to the geodesic aluminium dome

roof (ADR), which is fast becoming the norm in the energy industry for use on new-build petroleum tanks and retrofi ts to meet changes in environmental standards and other regulations.

Every ADR manufacturer has its own design preferences. As such, buyers should take a structured approach to bid evaluation to help ensure that they select the ADR that provides the best value for a particular project.

It all comes down to asking the right questions and knowing what to look for to ensure an ‘apples to apples’ comparison or, if the bids do not allow such comparison, factoring in the differences.

Breaking down the bidWhen evaluating competing bids for ADRs, buyers naturally look for the best value possible. That said, a multitude of elements need to be

Brian Thompson and Aaron Clarke, Matrix Applied Technologies, USA, explain why it is important to eliminate surprises when selecting a geodesic aluminium dome roof.

18Summer 2018

considered. To ensure that the ADR meets expectations while avoiding project impacts, such as unforeseen delays or high cost surprises, each bid should be thoroughly evaluated point by point.

Vendor validationWhen validating a vendor, be sure to look beyond its years in business to those who have drawn on engineering and innovation to provide a product solution that starts with ease of installation and provides engineered solutions to historically challenging issues, such as water and vapour leakage, custom requests, or structure stability under extreme conditions. Buyers should also ensure vendor-specifi c parts and assemblies that may be needed will be available.

Structure and designA vendor’s ADR structure specifi cations can have a large impact on project cost. For example, if an integral tension ring has not been included, a fi xed type of support with a steel tension ring will need to be installed on the tank shell. The ADR proposal will be less costly without an integral tension ring. However, the buyer is still exposed to additional costs, either after the fact through a change order or by reinforcing the tank shell.

Roof attachment points may incorporate a slide bearing with low-friction pads to minimise the horizontal radial forces transferred to the tank. As an alternative, the roof may be attached directly to the tank if the top of the tank is designed to sustain the horizontal thrust transferred from the roof. In general, there is no defi ned advantage between one or the other. Furthermore, it is easier to retrofi t an existing tank with an ADR that includes an integral tension ring, which in turn can save on installation costs.

For new tank builds, this is simply a preference. However, for gas tight or vapour tight domes, a fi xed type dome with tension ring installed on the tank shell will provide an improved gas tight design. This eliminates the need for fabric due to thermal expansion and contraction differences between a steel tank and aluminium dome.

Other structure and design questions to be considered include the following:

Has consideration been made for the addition of a suspended internal floating roof (IFR)? Suspending an aluminium IFR from a dome is a great way to increase tank capacity and reduce the need for workers to enter the tank. This can, in turn, improve safety by minimising confi ned space risks. If adding a suspended IFR is a possibility at a later date, one should consider purchasing a dome that includes suspension assembly points. The dome gussets and hub connection points will have a relatively small cost impact and will be outweighed by ease of switching to suspended IFR and increased tank capacity.

What type of struts are being used, and what is the impact to cost? There are multiple confi guration of struts currently on the market. These are typically custom extrusions similar to an I-Beam and will include single- or double-webbed sections with top and bottom fl anges. When designed, engineers take into account both the required strength to carry the design loads and weight-to-strength ratio. That being said, different levels of material effi ciencies exist, which will impact cost.

From a design perspective, is the ADR considered low profile or standard? Typically, the height of a dome is around 16% of the tank diameter. This is the most popular design offered in the market. Another option, when required, is a low profi le dome. This dome is usually requested when there is a total height restriction in the area, and is typically more expensive, such as near an airport or community worried about optics or appearances.

Is the ADR free vented or gas tight? Gas tight domes are more expensive due to the larger load requirements, which increase material use. For gas tight or vapour tight domes, a fi xed type dome with tension ring installed on the tank shell will provide an improved gas tight design.

Figure 1. Pre-engineered modules decrease installation time, reduce leak potential, minimise ongoing maintenance costs, and maximise asset longevity.

Summer 201819

Consider dome lifting options based on available laydown area at the project site. Preliminary discussions with a vendor about lifting options can reduce overall project time by addressing design and installation confl icts upfront. The dome lifting style can affect installation time and equipment cost (e.g. crane vs grip hoist). A vendor should be able to provide guidance in choosing a method that best suits a buyer’s needs.

Ask for specific information about water or vapour leak resistance. Look for innovative design features that eliminate or reduce this potential. Ensure the dome is not dependent upon heavy application of silicone sealant. When large amounts of silicone are applied in an effort to seal the ends of the battens and the hub covers, long-term exposure to light, temperature and humidity can cause the sealant to fail. Conversely, if well-designed, the top of the panels and battens are fl ush, which fi xes the main dome leak point: the hubs. Any applied silicone should then be tucked primarily beneath the hub cover, protecting the sealant from damaging elements. Additionally, designs that do not have grooves and lips limit the number of areas for water to pool.

Does the estimate include pre-engineered modules, such as the bird screen, skylight, and inspection hatches, or is it dependent upon on-site/field assembly? If the panel is precision engineered and pre-cut at the factory with welded/sealed curbs, these modules can be attached to the pre-cut panels to ensure no leak points are created during installation. This method also decreases the required installation time. Alternatively, on-site panels cut to suit accessories are fi eld assembled, however, extra fi eld time will be required and, if not properly executed, the dome is at greater risk for leaking and continued maintenance.

Design loadsThe design loads supplied on a quote should be compared with local regulations, as well as other competing bids. Some companies may only choose to meet the regulations and not give full consideration to the dome’s custom confi guration for the geographic location. When properly designed, these confi gurations ensure the dome can withstand environmental conditions at the build location. Critical design loads to consider when comparing bids include: live, wind, snow, seismicity, and internal and environmental pressures. The results of not doing so can be catastrophic.

Based on applicable regulations and vendor preferences, different factors of safety can be applied, which can affect the overall price and life span of the ADR. A good indicator is the dome weight, which correlates with the dome strut sizing or beam height, width and thickness.

Figure 2. Full consideration of local regulations with the dome’s custom configuration regarding the geographic location can ensure the aluminium dome roof will withstand environmental conditions; not doing so can be catastrophic.

Figure 3. Aluminium dome roofs could provide additional safety features compared to other alternatives including fire protection, protection from unauthorised access, and improved emission controls.

20Summer 2018

Material specificationsHas the vendor provided specifi c data on the panel sheeting, material fi nish, struts and gussets, gaskets, sealants, and hardware. Additionally, have they supplied supporting documentation?

It is important to ensure that these elements meet applicable industry standards. By not following industry standard material choices, owner/operators or engineering, procurement and construction (EPC) companies risk dome longevity due to failing gaskets, sealants, chemical compatibility issues and even structure under extreme conditions. For example, if an ADR is not designed for heavy uneven snow loads in a geographic area that experiences such events, the result could be a total loss of the dome.

AccessoriesDome suppliers offer a number of accessories, including inspection hatches, skylights, gauging platforms, radial walkways, rolling ladder connections, roof nozzles, IFR suspension systems, entry manholes, and sprinkler support systems, to name a few.

When comparing bids, it is essential to ask whether these accessories are included and which are pre-engineered for a more custom fi t. Consider pre-engineered walkways and platforms designed to meet the operation’s needs; doing so can reduce installation time and the need for skilled labour on-site. A buyer should also ask about potential future tank enhancements and the ability to retrofi t accessories to meet changing needs.

Indirect costsOther indirect costs can have a signifi cant impact on the bottom line, so it is important to determine whether

these items are included in the package price. Among them are installation, vendor supervision, shipping, lead time, equipment, design revisions and warranty.

It is also important to learn about the requirements for lay down area and whether the dome will be built inside or outside of the tank, which, as mentioned earlier, can impact the equipment needed to lift the dome. In some instances where the dome will be assembled on an existing external fl oating roof, the assembly location makes installation more complex. Additional structural supports and calculations may need to be considered.

Finally, ask about required lead time. The further ahead of schedule these client decisions are made, the more opportunity there is to reduce overall project cost. For example, maximising lead time can reduce shipping costs and ensure labour resources are not wasted due to delays or complications in receipt of materials.

Codes and regulationsCompliance with governing codes and regulations is an area that, when overlooked, could be costly. The bid request should identify all codes and regulations applicable to a project. Proposing vendors should also validate compliance during evaluation.

Even in the instances where API compliance may not be required, given the years of expertise that have led to the standard’s development, it is prudent to follow their lead.

ConclusionBuyers should take the time to evaluate each of these areas. It is this kind of ‘apples to apples’ comparison that will not only help eliminate surprises and hidden costs, but ensure a clear understanding of the short- and long-term value each vendor has to offer.

Figure 4. Designs that require heavy application of sealants may require ongoing maintenance, where innovative design features can eliminate or minimise leaks and reduce lifecycle maintenance.

Summer 2018212

In the world of petroleum storage, few solutions offer as much utility as fl oating roof tanks. While the technologies available to the industry are vast, the fl oating roof tank paved the way for bulk storage. The issue of storm water has been front and centre

since the beginning of storage needs. In today’s world, however, rain is, for the most part, still a rather unknown and unpredictable factor, which causes much frustration to tank farm operators. One common solution is to put a dome on top of an external fl oating roof (EFR), and turn the EFR into an internal fl oating roof, which would thereby remove the complication of storm water on top of the roof and the potential sunken roof. Yet, there are still weather conditions, climates and operator protocols that complicate the decision to use geodesic domes (g-domes)

for this purpose, i.e. locations that are prone to routine Category 4+ storms and/or where torrential rainfall is a regularity. In those locations, an EFR might be the best solution. For detailed guidelines and best management practices (BMP), the American Petroleum Institute (API) should be consulted.

So why bring up this topic? There are currently many best practices for managing aboveground storage tanks (ASTs). However, since there are so many products to be stored and just as many variances with regards to location and weather conditions, there is no one-size-fi ts-all standard operating procedure. Therefore, each terminal picks its own protocols. When picking a roof for storage tanks, there are several choices, which will be reviewed in this article.

Michael Sprung, EnviroEye LLC, USA, examines roofs and storm water management practices relating to aboveground storage tanks.

Figure 1. An external fl oating roof (EFR).

22Summer 2018

Geodesic domesSince the creation of the use of g-domes, the industry has been captivated by their strength and appearance. However, there are several examples where domes present future problems. There are even examples of facilities retrofi tting roofs from domes back to open roof fl oaters.

One of the fi rst obstacles when choosing how to protect a storage tank from storm water is the expense of installing a g-dome, with prices starting at US$300 000. Many operators have invested signifi cant funds into additional man hours in order to solve operational issues, and part of the thought train is the elimination of the storm water issue. One possible solution is to have a simple drain guard system, which would ensure that product will not leak from the roof drain line and would allow the tank to have an open valve to the roof drain.

Domes are so widely used across the US that some states have enacted laws requiring their use. Most municipal water ASTs call for covered roofs. For example, California has

instituted Rule 1178, which states that the vapours around stored product storage tanks must be contained and regulated, and it considers the dome the ‘perfect’ solution.1 Overall, the most relevant advice to dome operators is to ensure that service intervals that coincide with historical data for domed tanks are scheduled in. Maintenance upkeep is essential to ensure that the domes continue to meet needs and expectations.

Key considerationsCompanies should review their management protocols, considering factors such as the type of stored product, the location, weather and possible risks. Many facilities are reasonably well-established, meaning that they are old and already built. Over decades of use, routine servicing keeps the assets in working condition, and new owners fi nd themselves needing to stay on top of upkeep and upgrades.2 However, operators still struggle with stormy weather and the loss of product and potential of tank failures that come with it.

Below are some ‘fl ashpoints’ for inspectors when discussing ASTs. The use of domes has many advantages over the simple external fl oater. However, there are several complexities of having both a confi ned and hazardous space under the dome, which requires service workers to work for shorter times and with breathing devices. These conditions can more than triple the costs of most routine service work.

Wear and tear on the seals, seams, nodes, gaskets and other connection points can result in leaks, which could allow water to reach under the dome.

There are several options for treating the top of a storage tank. The use of domes can reduce the smell or emissions from product vapours, and they can all but eliminate the problem of having rain water trapped on top of a roof that has a closed roof drain line. However, there are several factors to consider for a long-term plan.

In addition to the leak points that can exist with a dome, the dome’s connection points to the top of the storage tank can act as shear points at the connection bolts. High velocity winds can lift a dome off of the top of a tank. The wind on a g-dome creates fl exing, and exposure to the elements causes the caulking to become brittle, which can crack as it ages. Again, proper upkeep can minimise this problem. Continuously having a load and then no load creates additional stress on the ‘batten bar’. Reducing the surface area of the roof so that the wind has less to catch can protect some farms from certain wind damage. Also, during storm season or torrential rains, storm water is still present in the dike around the tank, which creates another set of challenges for the operator. Regardless of the owner’s choice of solution, there are cost savings for a tank wishing to use a g-dome if installed during the construction of new tanks. Older tanks have the option of having the roof remain external or move to an internal model. Regardless of the age of the tank, new pressure calculations need to be considered.

The owners should consider why they want a quick and easy fi x. It can be diffi cult to get new technology approved for many of these situations. For example, consider the type of footwear that service operators prefer on top of a dome, and the requirements of the facility. Steel toed boots are probably standard, but shoes with good grip are often preferred by workers on top of a dome to avoid slipping and falling. But, it would be tough to get this footwear approved by the facility.

Figure 3. Workings of an EFR tank.

Figure 2. EnviroEye Drain Guard System.

Figure 4. Tank farm with an EFR.

Peripheral venting typically provided at the eaves

Fixed-roof centre vent

Fixed roof (shown as self-supporting aluminium dome)

External-type fl oating roof

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Facility regulations can confl ict with best practices for tank servicing, which can backlog a service that is waiting for approval. The need for a waiver under such circumstances can create a delay in service, which is costly.

Another example is that many domed tanks do not have walkways around them – service personnel must therefore ‘tie off’ to work, an impediment to service work. In any event, timing service accordingly can reduce some of these issues, and timing service during the less harsh weather season is a real cost-saving endeavor. Regardless, dome operators need to check on the seals and taping every three to fi ve years, along with other routine preventative maintenance measures.

During acute weather events, some systems that are in place year-round may need to be bypassed. Best practice involves planning for failure. It is not every day that a facility might be evacuated. Some conditions cannot be avoided, yet they can be ‘handled’. A proactive safety department can make modifi cations and workarounds before confl ict occurs. An effective manager will look at both sides of an issue for potential answers. With the advent of new technologies, the industry is moving towards standard practices. Modern technologies bring economic benefi ts and time-savings.

In the world of EFRs, a drain guard system for the roof drain valve would allow operators to avoid using a dome, have an insight into the condition of the drain line, as well as protection from its failure.

The EnviroEye Drain Guard System senses storm water from a tank roof and can detect product in the runoff from the roof. If product is leaking from the drain line, this solution triggers automatic valves to close while simultaneously sending an alert, such as a text message, to those that need to know and/or using audible and visual signaling.

ConclusionEach year, operators and managers prepare for the next storm season, as well as performing routine maintenance throughout the year. There is an ongoing role for the EFR in the storage industry, with the help of solutions that can, in turn, help to monitor storm water.

References1. ‘Rule 1178’, California, revised 2006. 2. 'Manual of Petroleum Measurement Standards', API.

Figure 5. System connected by a flange.

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Summer 2018252

T he use of internal floating roofs is common with bulk storage of liquid volatile organic compounds in aboveground atmospheric storage tanks. The pros and cons of the

various internal floating roof designs available to the market are often considered. However, less attention is given to the selection of the perimeter sealing systems for the floating roofs. This article will evaluate four common elastomeric wiper seal materials.

Four of the most common commercially available wiper seals in the market were selected for testing. A visual inspection, measurement of material hardness, and comparison of advertised physical properties were performed.

At the beginning of Petrex’s visual inspections, each wiper sample was cleaned with a lint-free rag. Wiper samples A and C had a shiny smooth finish. The surface of wiper B showed small dimples, which

Daniel C. Gray, Petrex Inc., USA, examines the importance of perimeter sealing systems for floating roofs through an

examination of four elastomeric wiper seal materials.

26Summer 2018

A razor knife was then used to cut the wiper into cross-sectional samples at various locations along their length to provide access to the interior of the profile. Before reporting the results of the testing, it is necessary to clarify the differences between micro-cellular and non-cellular cast moldings.

A micro-cellular wiper is often manufactured using a reaction injection molding technique.

Reaction injection molding is named from the chemical reaction that occurs when liquid polymers are injected or poured into a heated mold. The two parts of the polymer are mixed together. The mixture is then injected or poured into the mold and allowed to expand to fill the mold and then cure. The reaction of the polymers in the mold causes the material to expand, which creates a molded part that has a high density outer skin with a lower density inner core. The core has a lower density because a multitude of minuscule air pockets are formed in the reaction process. These cells are closed off between each other and there is no evidence that they will absorb product if they are exposed to it (Figure 2).

The non-cellular molding process uses external thermal mixing equipment that thoroughly combines the polymer components to a homogenous mixture outside of the mold. The mixture is then injected or poured into the heated mold and allowed to cure. Because it does not require a chemical reaction to fill the mold, there are no air bubbles or cavities within the material. The result is a solid cast material (Figure 3).

The cross-sections of the wiper seals were examined using a magnifying glass. The core of wiper A was consistently solid, matching its advertised non-cellular property. The core of wipers B and D were consistently micro-cellular, although the cell size in Wiper D varied widely. Wiper D had a skin layer on the outside that had a thickness of between 0.005 in. and 0.080 in. This trait was not observed in any of the other wiper seal samples involved in this inspection. Wiper C varied between micro-cellular and non-cellular.

The samples were then tested for hardness using a shore A durometer

appeared to be air bubbles. Wiper D had a black smooth finish but showed inconsistent white swirling patterns in all inspected samples (Figure 1).

A closer inspection of the seals with a magnifying glass revealed that all of the samples exhibited small markings, which may be attributed to imperfections in the mold cavity surfaces. These markings are very faint and nearly invisible to the naked eye. There was no evidence of structural degradation caused by these markings.

Figure 2. Microcellular cross-section.

Figure 3. Non-cellular cross-section.

Figure 1. Swirling pattern.

gauge, with each sample receiving a total of 20 measurements at various locations. The purpose of this was to test the consistency of the urethane material. The results of the durometer check showed that wiper seals A, B, and C were relatively consistent and had median values of approximately 81 for wiper A, 69 for wiper B, and 71 for wiper C. Wiper D was the most inconsistent, with median values ranging from 39 to 81.5. The results of the hardness measurements of all of the samples can be seen in Tables 1 – 4. It is necessary to note that the number of samples tested from the various manufacturers is based solely on the quantity of wiper seal samples available at the time of testing.

Like all other internal floating roof seal systems, wiper seals are not impervious to failure. The life of any wiper seal is dependent on many factors including (but not limited to) the condition of the inside of the tank shell, the number of tank cycles, the product stored in the tank, and even the climate in which the tank is in operation. One of the most common failures is tearing of the seal. A portion of these failures can be attributed to some aspect of the seal installation. The slip of a razor knife when making a seal splice can result is an accidental cut that presents a weak spot for a tear to propagate. Other tears start randomly along the length of the seal in areas where no weak spot can be identified.

During testing, wiper D proved to be the most prone to tearing in the lengthwise direction. It has been noted on several failures that the tear will start in a lighter swirled area of the seal. When the tear travels through the swirled area until it reaches the transition point to the darker section of the seal, the tear is generally redirected back into the lighter area (Figure 4).

Closer inspection of samples cut from both the swirled and darker sections revealed that the cross-section of the darker section had a visibly thicker skin.

This does not prove with certainty that all micro-cellular wiper seals that have varying skin thicknesses are more prone

to tearing, but it does seem possible that the swirling pattern in this case may play a role in the tearing failure. Independent third-party testing would be required to confirm this. The cause of the swirling is also unclear. It can be theorised that it is present due to an incomplete mixture of the polymer components prior to molding. Additional testing would be required to confirm this.

Another common failure is the physical breakdown of the seal material. The visual appearance of this type of failure results in the wiper seal appearing similar to a rubber part that has dry rotted. The duration of time for this breakdown to occur while the tank is in service

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varies greatly. In Petrex’s experience, such failures can happen within as little as two years of service and in tanks that have been in service for up to seven years. Tank operators generally identify this type of failure when pieces of the seal are trapped in the tank’s outlet straining system.

The exposure of a wiper seal to chemical attack has also been noted as a cause of failure. This can be from improper selection of seal material for the product application. It is always advised for a purchaser to check chemical compatibility of the seal material with the product to be stored.

A more preventable chemical attack failure can occur when the tank is being coated internally with an existing internal floating roof and seal system. Discussion with individuals in the urethane industry revealed that when a urethane material is exposed to a solvent in either liquid or vapour form, it can cause the molecular structure of the material to break down and soften. When the solvent is removed, the urethane material will stiffen and lose flexibility. The effects are more severe with liquid contact than vapour exposure. All epoxy coatings contain some degree of solvent to enable the coating to adhere to the tank’s carbon steel surface. The solvent portion of the coating evaporates during the drying process and is released into the atmosphere inside of the tank. If a urethane wiper seal is exposed to this solvent rich atmosphere, the possibility of degradation is present.

Methyl ethyl ketone (MEK) is a strong solvent that is commonly used to clean coating equipment in field applications. During a tank bottom coating process below an internal floating roof, over spray can deposit on the underside of the floating roof and the underside of the seal system. To test the effect of direct exposure of wiper seal to liquid MEK, the following tests were performed.

For the first test, all four wiper seal samples had

Table 1. Wiper seal A durometer check (shore A scale)Mean Range Median Standard

deviation from mean

Maximum Minimum

Sample 1 (outside surface) 82.6 2.5 82.0 0.9 84.0 81.5

Sample 1 (core) 80.75 7.5 81.0 2.3 84.5 77.0


Sample 2 (core) 81.1 4.0 81.25 1.0 83.0 79.0


Sample 3 (core) 79.65 5.5 79.75 1.5 81.5 76.0

Table 2. Wiper seal B durometer check (shore A scale)Mean Range Median Standard

deviation from mean

Maximum Minimum


Sample 1 (core) 68.3 4.0 68.5 1.3 70.0 66.0

Table 3. Wiper seal C durometer check (shore A scale)Mean Range Median Standard

deviation from mean

Maximum Minimum


Sample 1 (core) 70.85 4.0 70.75 1.25 73.0 69.0


Sample 2 (core) 69.8 3.0 70.0 0.81 71.0 68.0


Sample 3 (core) 70.3 3.5 70.0 1.05 72.5 69.0

Table 4. Wiper seal D durometer check (shore A scale)Mean Range Median Standard

deviation from mean

Maximum Minimum


Sample 1 (core) 38.6 11.5 39.0 3.2 42.0 30.5


Sample 2 (core) 53.95 35.5 48.75 13.9 72.0 36.5


Sample 3 (core) 48.9 48.0 38.75 17.4 76.5 28.5


Sample 4 (core) 70.6 8.0 70.75 2.4 75.0 67.0


Sample 5 (core) 72.9 19.0 71.0 6.0 84.5 65.5


Sample 6 (core) 61.3 33.5 60.0 12.3 76.5 43.0

30Summer 2018

liquid MEK applied to them with a clean lint-free rag. Each sample showed physical degradation to the surface where the solvent was applied. The surfaces had a shiny, almost slimy, appearance with a texture that felt like a light coating of oil. This appearance quickly disappeared as the solvent evaporated. After evaporation, wipe marks were visually present on all four samples.

In the second test, four samples of wiper C were attached to a test fixture and placed against a carbon steel plate to replicate the upward installed position of a wiper seal. Both a standard 6 in. and a compressed 4 in. rim space were duplicated. Samples 1 and 2 were included as control samples. The undersides of samples 3 and 4 were wiped with MEK. All four samples were isolated in a MEK vapour rich environment for 66 hrs. The test enclosure was then opened and the samples were allowed to sit for 24 hrs before the carbon steel plate that served as the tank shell was removed. Figures 5 and 6 show before and after photos of this test. It demonstrates that samples 1 and 2 returned to normal position while samples 3 and 4 had taken a compression set in the upward position and had stiffened from their pre-test condition.

This evidence is only circumstantial and it must be noted that many tanks have received internal coating with no damage to existing wiper seals. The simplest way to prevent chemical attack from the stored product is to check the chemical compatibility from the seal supplier. It is also advisable to check the compatibility of standard urethane or the wiper’s material of construction to the product to be stored using one or more chemical compatibility sources readily available online.

In summary, the number of failure examples included in this contribution are extremely small in comparison to the number of wiper seal installations on internal floating roof systems and should not deter the use of this type of seal system. The vast majority of wiper seal installations experience only the standard wear of an elastomeric type seal.

Figure 5. Samples before testing.

Figure 6. Samples after testing.

Figure 4. Tear path redirection

Summer 2018313

L eak detection tasks are usually associated with relatively small underground storage tanks (USTs), such as gasoline or diesel tanks in gas (petrol) stations.

However, aboveground storage tanks (ASTs), such as petroleum marketing, pipeline, and refinery tank farms; field constructed underground bulk storage tanks (FCUBSTs); and cut-and-cover tanks, which are constructed and buried underground, all require a leak detection solution to prevent ground water contamination, product loss, environmental fines and clean-up costs.

Clear guidance and standards for leak detection in larger tanks are currently not provided by the US Environmental Protection Agency (EPA), as well as state and local governments. However, leaks from larger tanks could be devastating to the environment due to the larger volume of liquid product. Leak rates can also increase due to higher pressure, thus spreading over a greater area and ground depth.

The task of leak detection is difficult for larger tanks. The regular requirements for small underground tanks are 0.1 gal./hr for tank tightness tests and 0.2 gal./hr for leak detection tests at a minimum of

Alexander Bukhman, Gauging Systems Inc., USA, compares leak detection methods for aboveground storage tanks.

32Summer 2018

95% probability of detection and maximum of 5% probability of false alarms.

The time required by most leak detection systems is 48 hrs, though claims of 24 hrs for small tanks are not uncommon. In Table 1, 0.2 gal./hr is used as a target leak detection threshold over a 48 hr period to calculate the resulting level change in an aboveground storage tank (vertical cylinder tank).

To understand the difficulty of the problem, it is important to not only consider the small changes in level caused by small leaks in large tanks, but also various influential factors, such as temperature change.

Every 1.2°F of average temperature uncertainty will introduce an uncertainty of 1/16th of an inch per every 10 ft of height in any vertical cylindrical storage tank. This means for an average tank that is 30 ft high, 1.2°F of average temperature uncertainty will result in 3/16th of an inch of level uncertainty. Compare this value with the level changes required for leak detection in Table 1 and the overwhelming influence of temperature factor becomes obvious.

While uncertainty of average temperature is one of the strongest factors influencing leak detection in ASTs, FCUBSTs and cut-and-cover tanks, it is not the only factor. Thus, even when 0.5 or 1 gal./hr thresholds are deemed acceptable, reliable leak detection still remains an extremely difficult technical task.

Mass-based approach vs level-based approachThere are two approaches to leak detection systems based on measurements of quantity change in tanks: level-based and mass-based.

The level-based approach is widely used in small underground tanks, such as service station tanks utilising mostly magnetostrictive technology, where the position of float on a rigid guide is measured using a magnetostrictive method. The same probe usually incorporates temperature measurement to compensate for the temperature effect. This technology has been certified in small tanks.

In large storage tanks, where a flexible guide for a magnetostrictive probe has been used, the effect of

temperature on liquid expansion and float buoyancy is enough to make this technology inapplicable.

Mass measurement methods have a significant advantage over level measurement methods because unlike level and volume, mass does not change when temperature changes. Mass measurement methods are based on a hydrostatic approach.

A pressure sensor positioned near the bottom of the tank in a stable environment would read the same pressure during a ‘zero leak’ situation, whether the temperature of the liquid changes by 1°F, 10°F or does not change at all. At the same time, an accurate pressure sensor will read changes of pressure (mass) if there is a leak independent of temperature change or temperature-induced level change. This is because pressure is proportional to both density and level. In an ideal cylindrical tank, level increases in the same way as density decreases per every degree of temperature rise and vice versa.

There is no alternative to mass-based leak detection in large storage tanks.

Traditional hydrostatic tank gauge (HTG) systems, with gauge pressure transmitters mounted on the wall of the tank, are affected by differences between the liquid and ambient temperatures. It would be difficult to accurately detect mass trends in conditions where there is no synchronisation between vapour and liquid pressure sensors. Furthermore, the influence of the dead zone below the standard bottom HTG sensor will not be compensated for. Traditional HTGs do not accurately compensate for tank shell expansion in ASTs.

Traditional HTGs cannot be physically used for cut-and-cover or buried tanks, concrete wall tanks or underground storage facilities. Thus, other approaches to hydrostatic systems for mass-based leak detection have to be considered.

Leak detection as service vs permanent leak detection solutionSome mass-based leak detection systems were developed as a service method, which means a crew of technicians would go to a tank site, install the equipment and monitor for a period of time, usually 48 hrs or more, to determine if there is an existing leak.

The sensors for such systems are usually enclosed within a probe inserted into the liquid in order to avoid the environmental influences discussed previously.

While this method can provide better accuracy than the level-based methods, it only checks for leaks during the period of time when service is provided at the tank site. Thus, if the leak was present before the service, environmental damage has probably already occurred.

Most states’ regulations require annual, quarterly or even monthly static leak detection tests, depending on a tank’s age and construction.

Table 1. Level change vs tank dia. for given leak rateTank dia. (ft) Leak rate

(gal./hr)Time period for leak detection (hrs)

Level change (16th in.)

25 0.2 48 0.50

50 0.2 48 0.13

75 0.2 48 0.06

100 0.2 48 0.03

125 0.2 48 0.02

34Summer 2018

Service-based leak detection involves installing and removing equipment to perform a (48 hr) static test, which is expensive and impractical to detect a leak when it occurs.

There are some mass-based systems that are permanently installed in the tank. Some of these systems include the use of a special differential pressure sensor with pneumatic control, requiring the tank to be taken out of operation for installation purposes (emptying of the tank, cleaning of the tank, venting of the tank, loss of use, etc.).

This alone would be of significant cost for tank operators, especially for ASTs and large underground tanks. The failure of a single sensor or the pneumatic control would also require the tank to be taken out of operation. Such systems may require special equipment, software and personnel to conduct the leak detection test.

None of the methods described are applicable for all possible tank shapes or conditions when temperature change or density stratification occurs during the leak detection test process. That is because compensation of level and density only work correctly in cylindrical tanks. It is important to note that these systems do not have temperature sensors to compensate for tank shell expansion.

Mass-based multi-sensor approachAn alternative solution is a multi-sensor mass-based method, using a multitude of accurate absolute pressure and temperature sensors installed within a slotted gaugewell (standpipe). An example would be a multi-function tank gauge (MTG). The sensors should be positioned near the bottom of the tank, throughout the tank depths, and in the vapour space. The sensors should be operated by a single processor, capable of timing and synchronising the measurements of the different pressure and temperature sensor modules.

Such a modernised hydrostatic mass-based approach would allow for the following:

Installation into an above or below ground tank facility without emptying the tank.

Statistical analysis, allowing the influence of any single pressure drift or failure to be minimised.

Compensation of temperature influences on the pressure sensor performance.

The use of sensors with different span over tank depths for optimal sensitivity.

Compensation of temperature influence for even slight irregularity of tank geometry and corrections for the temperature related tank shell expansion.

Immunity from environmental factors by using absolute pressure transducers.

Synchronised measurements in vapour and liquid to exclude the influence of the vapour or ambient pressure noises.

Redundancy to allow exclusion of malfunctioned sensors from leak detection test analysis as

opposed to aborting the tests and requiring immediate repair in case of single sensor-based systems.

The method can work as a fully automatic system but can also log historical data, allowing analysis of the raw data and manual statistical evaluation of each situation or suspected leaks.

Integration of leak detection and the tank gaugeThe multi-sensor mass-based leak detection approach can be utilised as both a tank gauge system and a continuous leak detection system. However, a correctly engineered configuration of the gauge is required when used for leak detection. For example, redundant bottom and vapour sensors should be used in a multi-function gauge to increase the reliability of the leak detection. The total number of sensor modules must be chosen to provide enough redundancy and statistics depending on the minimum leak detection threshold required and the static time available and necessary for each storage tank to run the leak detection test procedure.

Engineered approachThe task of leak detection for any large storage tank, whether above or underground, must always be considered through an engineered approach. The size, type and location of the tank will influence the minimum leak detection threshold and the required leak detection test duration, as well as the number of sensors and their location in a multi-sensor mass-based leak detection gauge. The height of the tank, the available access for the installation of the system through the tank roof, and any limitations of the underground storage facility must also be evaluated.

The multi-sensor mass-based probe is usually able to accommodate tank site limitations by means of its sectioned design and the fact that only a single penetration through the roof is required.

For each individual tank, an engineered approach is required to determine the most suitable technology, the cost factors and the proper configuration within the chosen technology.

ConclusionThe mass-based method is the most feasible approach to leak detection for ASTs, FCUBSTs, and cut-and-cover tanks.

While service-type and permanent-type mass-based leak detection methods may work for the same tank, it is important to determine whether the choice of leak detection should be a permanent solution or a periodic service.

A multi-sensor mass-based system provides the most flexibility in configuration and the least dependence on individual sensor failures and influential factors. This type of leak detection system can be configured as a tank gauge and a leak detection solution with the same instrument.

Summer 201835

In an environment of increased storage capacity, ageing assets, and increasing safety and environmental regulations, tank farm operators are confronted with several challenges. Adequate

emissions measurements are essential for managing storage tanks. Tank farm owners want to benefit from excellent incident figures, high asset availability, and low insurance fees.

Storage tanks hold hydrocarbon product for brief periods of time in order to stabilise flow between production and pipeline, trucking or shipping distribution. During storage, loading and unloading, and daily or seasonal temperature changes, light hydrocarbons vaporise. These light hydrocarbons include methane and other volatile organic compounds (VOCs) and hazardous air pollutants (HAPs), such as benzene, toluene and xylene. These gas vapours collect in the space between the liquid and the fixed roof of the tank. When loading storage tanks, these gases are often vented to the atmosphere or flared.

Similar to the challenges detected at refineries or other production installations, all gaskets, connections, valves, pumps, etc., that are found around and on a tank are also susceptible to fugitive emissions.

Bart Wauterickx and Bas Hermans, The Sniffers, Belgium, explain how a combination of measurement techniques can help ensure a complete leak detection survey.

36Summer 2018

Seals and gaskets age and are subject to both external and internal circumstances, such as temperature or pressure variations and mechanical movements. Typical storage tank components that have to be included in a thorough survey are floating roof seals, rim seals, overflow drains, vacuum breakers, access/inspection hatches, guide poles, gauge floats, pontoons and vents.

VOCs emitted to the atmosphere react with the NOX, forming an O3 ozone and particulate matter. Due to the negative impact on air quality, VOC emissions have to be prevented.

HAPs are often regulated by local or national authorities. In several cases, companies set the emission levels from their storage tanks lower than legal requirements in order to be consistent with their ambition to be a reliable, sustainable company that minimises emissions using the best available technology.

A proper leak detection survey combines different measuring techniques in order to identify and quantify the leaks. Techniques include:

Photo ionisation detectors (PIDs) or flame ionisation detectors (FIDs): these are well-known measurement instruments for leak detection and repair (LDAR) surveys in oil and gas, chemical, and petrochemical companies. They conduct measurements according to the EPA Method 21 protocol – the global standard in emission legislation for managing or reducing fugitive VOC emissions from industrial installations.

Optical gas imaging (OGI) with an infrared camera: this camera technique allows companies to visualise the emission of VOCs from a source.

High flow sampling (HFS): this technique is used to quantify a detected leak based on a flow rate and concentration measurement.

An OGI camera inspection involves a quick scan of the storage tank. This immediately shows the leaks, allowing a maintenance department to start planning repair activities. The advantages of an OGI screening can be important for the customer. The survey is fast and, therefore, more economical than an LDAR survey with PID/FID. In addition, OGI can tackle large leaks – the highest emitters and the highest risks – in an installation. However, one should be aware of the constraints of camera detection.

Figure 1. Initial logging of the breather valve – 2870 kg/yr emissions.

Figure 2. Logging after repair of the breather valve – 267 kg/yr emissions.

Figure 3. Benchmark of emissions on tank farms worldwide.

Measurements with PID/FID according to EPA M21 are often superior in quality and accuracy than the OGI camera. The influence of weather conditions (such as wind, rain and temperature), the relative position of the inspector (impacted by the sun’s reflection and background contrast, etc.), and the qualification of the inspector, make a large difference in the quality of the detections. Even with experienced and certified technical operators, the detection limits of OGI vs PID/FID measurements are not on par.

Balancing techniquesA recent study involving a shadow measurement of 11 000 sources (both PID/FID and OGI measured), demonstrated the lower detection level for OGI. Where PID/FID detected 7.7% of the sources leaking above 9 ppm (the lowest detection limit), only 1.2% of the sources were leaking according to OGI. Only one out of seven leaks was found using the OGI camera. Similarly, where the PID/FID measurement detected 4.5% of the 11 000 sources leaking above repair defi nition (500 ppm, 1000 ppm or 5000 ppm, depending on the nature of the source), only 1.2% of the sources were detected with OGI. The OGI camera was unable to identify 225 leaks above repair defi nition. Of the 167 pegged leaks (above 100 000 ppm) detected with PID/FID, only 119 leaks (70%) were found with OGI. Thus, even larger leaks were not detected with OGI. On the other hand, 24 leaks (out of 869) were detected with OGI that were not with PID/FID because the sources were inaccessible, insulated and on iced equipment.

Hence, the best practice is to employ the PID/FID measurement whenever possible and engage OGI where PIF/FID cannot be used. This combination ensures a correct and complete leak detection survey.

ComplianceFor tank inspection, the NTA 8399 guidelines for detection of diffused VOC emissions with OGI is a reference document for some legislation. Conforming to NTA 8399, tanks need to be

checked by means of an infrared camera annually or biannually, depending on the stored product. Following an inspection, a detailed report with emissions findings, including images and video material, is presented. Repairing leaks must be completed directly after the inspection. If leaks cannot be repaired within a certain timeframe, the reason for this delay should be stated in a detailed repair plan.

Recent developmentsA recent development is the explosion-safe camera. Screening for leaks with electronic equipment, like a

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38Summer 2018

camera, in a hazardous environment requires a proper understanding of explosion risk. Explosion-safe cameras are designed to work fully in Zone 2 Class I, Division II areas and are, therefore, suitable for use where there is a risk of gas collection and ignition with a stray spark or hot surface.

Moreover, key measurement equipment suppliers are developing a device that can automatically quantify leaks based on the images taken with the camera – so-called quantified OGI (QOGI). The Sniffers is actively following this evolution and participates in different test setups and comparison scenarios. This is a promising development that requires a better understanding of the niche applications where it can add value.

A storage tank can be a dynamic installation with moving components. A floating roof, with or without rooftop coverage, has a different emission pattern in an empty tank compared to a filled tank or during the loading and unloading process. Therefore, emissions from the storage tank can vary with the dynamics of the process. An example is floating roof sealing as this can be 100% tight at one height but leaking at other heights. Continuous logging of some critical seal zones is the correct practice to measure the real exhaust from the roof seal.

A recent case study of a breather valve on a benzene storage tank has illustrated the sometimes unexpectedly high emissions. A logging of the breather valve demonstrated the faulty valve was causing emissions of 2.91 kg/yr of benzene. After fine-tuning the pressure settings, benzene emissions were reduced to 0.26 kg/yr.

What results can be expected?On average, an emission reduction of 75% is within reach, and sometimes an even higher reduction of up to 90% is achievable. A dedicated benchmark study with 13 tank farms was conducted. These tank farms had between 3000 and 35 000 potential leaking sources. The number of leaks identified and quantified varied between 10 and 1200 for the bigger farms.

Of the 13 surveyed farms, 40% had unacceptable emissions. In fact, emissions as high as 100 000 kg/yr were detected. The tank emission measuring campaign was executed as a combination of PID/FID measurements and OGI infrared camera screening, followed by a quantification of every OGI visualised leak with the high flaw sampling technique. This approach made it possible to sort the identified leaks from high to low and, consequently, focus the maintenance efforts on the largest leaking sources first.

A thoroughly-developed software package, such as The Sniffers’ SFEMP tool, makes it possible to manage all of this emission data and provide the customer with the data, analysis capabilities and report generation needed to significantly reduce these emissions. This technology helps to ensure proper condition-based maintenance and allows for easy selection of HAPs to analyse the leaking sources to create a safe operating condition. Official emission reports and meaningful maintenance repair orders for fast maintenance actions can be created. The tool also helps companies to prioritise capabilities to limit maintenance costs and efforts for maximum emission reduction effects. The tool can also help stimulate a culture of continuous improvement by reviewing historical performances per source or per source type to introduce best maintenance practices.

ConclusionAn effective tank emission reduction is a programme, not a project. All installations age, and a small leak almost never spontaneously stops leaking. Therefore, an annual, focused survey is required to continuously address leaks with immediate repairs and introduce enhanced practices in specifications, purchase tactics, installation methods and maintenance interventions. As inspections drive cost in a condition-based maintenance environment, a customer should rely on a certified or accredited service provider. This provides customers with peace of mind when receiving emission data, analyses, findings and recommendations.

Figure 4. Datalogging on a fixed roof tank breather valve.

Figure 5. Infrared camera screening.

Summer 2018393

C ompanies involved in the transportation and storage of oil and petroleum products pay great attention to the diagnostics of tanks as they cannot allow spills and leaks to happen.

Cooperation with specialised companies that provide tank diagnostics allows operators to meet ever higher requirements in the field of environmental safety, as well as to avoid fines.

Diagnostics without decommissioningArguably, the most promising of tank diagnostics methods are those that allow diagnostics to be carried out without suspending the operation of tanks. These methods offer significant economic benefits. Tank decommissioning, emptying and cleaning come with significant costs, and additional financial losses can be incurred due to forced downtime of the tank.

Roman Filatov, Transneft Diascan JSC, outlines the benefits of tank diagnostics methods that do not require decommissioning.

Figure 1. Tanks fl eet of Transneft PJSC.

40Summer 2018

Tank diagnostic methods that do not require decommissioning include acoustic emission diagnostics of the wall and bottom of the tank, the use of a diagnostic robot to examine the bottom of a filled reservoir, and the control of the edge bottom plates using guided waves.

Acoustic emission diagnostics is based on the registration of elastic vibrations that are emitted by a source when under a certain pressure. The purpose of

acoustic emissions control is to identify defects that have been developing or may develop in the near future (registered while changing the pressure levels), determining the defects’ location and assessing their danger. The quantitative characteristics of defects (such as dimensions, orientation, etc.) identified by acoustic emissions are determined by other methods of non-destructive testing (NDT).

A new method of tank diagnostics is also currently under development – a robot to inspect the bottom of a tank without removing the reservoir from service. The diagnostic robot includes several key elements, including an ultrasonic sensor unit, a magnetic system with hall sensors that detect magnetic field changes (in some models), a positioning unit, and a stripping system. The robot is positioned in the tank through the access door. The device conducts bottom diagnostics and transfers the results of the inspection over a connecting cable to a computer. The results are presented in a map of the bottom of a tank with the corrosion areas indicated.

It is possible to undertake tank diagnostics procedures without decommissioning by monitoring the bottom of the tank using directed waves. Directed waves are spread over long distances across the installation site of the transducers to reflect any change in the cross-sectional area of the object. Such changes may include corrosion damage, as well as local and extended defects. The structural elements of the object, such as welded seams and tie-ins, are also identified by directed waves.

Laser scanningLaser scanning is one of the latest developments in the field of NDT applied to tank diagnostics. This model makes it possible to obtain a digital model of the surrounding space, representing it as a set of points with spatial coordinates. The operating principle of a laser scanner assumes automatic measurement of the distance to the object and two angles (vertical and horizontal), and the subsequent automatic calculation of the spatial coordinates of the object. Laser scanning allows accurate spatial coordinates to be obtained of the wall and roof surfaces of the tank.

This method reduces labour costs in comparison to traditional geodetic measurement methods. It is primarily used to compose terrain plans and sketches of large industrial facilities. The general trend of laser scanning technology development continues to be enhanced by the ever-increasing accuracy of laser scanners. This method is used to monitor the construction of Transneft tanks, as well as for planned diagnostics.

New technologies for tank diagnosticsIn today’s competitive tank diagnostics market, service providers are engaged in the development of new diagnostic methods and technologies. Transneft Diascan has been developing a technology to facilitate ultrasonic testing of welded joints using a mechanised

Figure 2. Preparation for acoustic-emission control of the tank.

Figure 3. Installation of acoustic-emission control converters.

Figure 4. Ultrasonic scanning of the reservoir.

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ultrasonic system with phased antenna array (PAA) technology and the time of flight diffraction (TOFD) method. PAA technology provides the ability to control the shape and direction of an ultrasonic beam electronically. TOFD is a diffraction-time method of ultrasonic testing, based on the interaction of the edges of material irregularities with ultrasonic waves.

The mechanised ultrasonic system consists of a multichannel ultrasonic flaw detector, which allows several inspection schemes to be implemented simultaneously, and a scanner with several ultrasound transducers using PAA technology and the TOFD method. The scanner can be moved either manually or using an electric drive. The use of a mechanised ultrasonic system with PAA technology and the TOFD method allows for the detection of defects of various types and different spatial orientations located in the weld seam and the thermal influence zone in one run, which increases the efficiency of diagnostics.

At present, PAA and TOFD technologies are used to control small lengths of welded joints, for example, during additional flaw detection after in-line diagnostics of main pipelines. This new method allows for highly efficient ultrasonic testing of objects with a large length of welded joints, such as oil and oil product storage tanks.

The system has recently been tested and will be put into operation in 2018 – 2019. To date, few analogues exist, and these are used only in the construction of

trunk pipelines as a replacement for the radiographic method of control.

ChallengesSome of the greatest difficulties in the tank diagnostics market are the differences in the regulatory documentation that cover the diagnostic procedures of various tank operators. This leads to differentiation with regards to the methods and volumes of diagnostics, as well as the diagnostic equipment used. Transneft Diascan has a range of equipment for tank diagnostics, and performs a full range of works on technical diagnostics of vertical steel tanks for storage of oil and oil products with volumes of 100 – 50 000 m3. On average, the company diagnoses approximately 400 tanks operated by Transneft annually.

The terms and conditions for the safe operation of both tanks and their elements are calculated based on the results of technical diagnostics and identified defects. The subsequent analytical report also includes recommendations for future operation.

ConclusionTimely and high-quality tank diagnostics are key to ensuring high operational reliability of the oil product storage system. Proper assessment of the technical condition of the reservoir facilitates the provision of relevant recommendations for a safe service of the storage and correct calculation of its lifespan.

Summer 2018434

I nspections of aboveground storage tanks (ASTs) are performed worldwide under a range of environmental conditions. One thing these structures have in common is the requirement to

clean the asset properly so that inspections may be performed correctly. As asset owners are looking towards more advanced methods of efficiently performing inspections, equipment manufacturers are designing new, state-of-the-art technology and equipment to perform these inspections with a minimum amount of cleaning.

This article focuses on the efficiency improvements that modern inspection technologies

and systems can bring to the overall inspection process of an AST’s bottom, shell, and roof.

Non-destructive testing (NDT) of ASTs requires a variety of inspections to satisfy the requirements of various codes, e.g., magnetic-flux leakage (MFL) inspections on a tank bottom or ultrasonic thickness (UT) measurements on a tank’s shell and roof. Increasingly, these inspections are performed with robust inspection systems designed to work under natural conditions and with fewer cleaning requirements. Most of these systems will have either data-recording or data-mapping capabilities, which enable post-analysis of inspection data and provide

Edwin Van Der Leden, Neil Randal Pearson and Damian Gallagher, Eddyfi, UK, outline methods to help improve storage tank inspection efficiency.

Figure 1. Tank bottom mapping inspection.

44Summer 2018

numerical input to risk-based inspection (RBI) and inspection data management (IDM) systems.

Cleaning tanks internally is costly and requires tank downtime. To keep this outage to a minimum, asset owners select cleaning processes that are safe, easy and efficient, whilst still achieving the required end results.

In order to keep the cleaning time to a minimum, it is important to select an inspection technique that is able to measure through some degree of surface debris and coating, while eliminating the need for sand blasting the bottom. For instance, MFL merely requires a ‘brushed’ cleaned surface. This technology has become a favoured method for inspecting tank bottoms efficiently, without the need for excessive cleaning.

MFL equipment is available from various suppliers. While manual, lighter, simple, detection-only systems work well on a combination of thin plates and coatings, they are less capable of providing the necessary sensitivity on thicker plates and thicker coatings.

Advanced methodsMore advanced MFL systems provide a greater magnetisation, allowing full saturation of the plate under test and ensuring correct sensitivity. The advanced systems can be used to detect down to 20% of plate thickness loss.

During inspections, top/bottom surface discrimination has significant benefits, as it can impact the repair approach. The well-known surface topology air-gap reluctance sensors (STARS) technology provides automated discrimination between top-side and bottom-side defects.

Systems with a high number of sensors, coupled with advanced mathematical algorithms, help to provide a relation between the defect found and its relative size. The output is a high-resolution, easy-to-understand visual representation of the inspection surface.

Most MFL systems can be used in auto-stop mode, as well as in a mapping mode. With advances in computer power, speeds of up to 1 m/sec. (3.2 ft/sec) can be achieved without losing any data quality. This is a major efficiency improvement (time savings up to 30% were reported on an average five-day inspection job).

Another major efficiency improvement can be gained when inspecting shell-to-annular welds. Most inspection codes and specifications recommend visual testing or magnetic particle inspection (MPI). For both of these techniques, the surface needs to be clean of any debris, and the coatings removed. The process for both visual inspection and MPI inspection is slow and the inspection quality depends on the skill of the inspector as defects can be misinterpreted, missed altogether, or incorrectly reported. With the use of alternating current field measurement (ACFM) or eddy current (EC), in combination with an array probe, the inspection is both faster (up to 0.6 m/sec. [2 ft/sec.]) and more reliable as all of the inspection data is recorded and stored in the equipment. This data can be used in reporting extended inspections or repair activities. ACFM and EC are also capable of inspecting through coatings and paint without the need for excessive cleaning or sand blasting, resulting in an overall improvement in efficiency.

Inspecting under harsher conditions and environments While the inside of a tank must be thoroughly cleaned for various inspections, there are also parts of the tank that can be inspected with much less cleaning or even while in service. Tank shells can be inspected from the outside using UT, for example. UT is not greatly influenced by a tank that is filled with product, although the density of the product may affect the amount of reflected energy. In-service testing may have additional safety requirements. As most, if not all, equipment is not ATEX rated, additional measures must be taken, such as gas testing and the availability of ‘hot work’ permits. In-service inspections can also be carried out on tank bottoms, but this requires complex inspections with expensive equipment that can have several limitations, such as the inability to perform repairs without emptying the tank. The use of UT equipment for shell thickness inspections is easy and cost-effective.

In some regions, tank shell inspection is still performed using scaffolding or rope access to manually collect spot measurement thickness data with UT. Good practices and procedures dictate that measurements have to be taken on each tank course and ring. Measurements must also be performed at fixed distances around the tank and be equally distributed over the course of each wall plate, from the bottom to the top of the tank. The number of vertical scans of a tank shell is proportional to the

Figure 2. Inspection output – tank bottom map detailing corrosion location and severity.

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46Summer 2018

diameter of the tank, usually with a minimum of eight cardinal scans. Doing this manually can be time consuming and the results rely on the spot-check positions at which the measurements are taken, which can result in defects being missed altogether. Due to the sporadic nature of spot checks, evolving corrosion spots can be missed, giving a false representation of the integrity of the asset. Remote ultrasonic inspection crawlers provide a more efficient way to assess tank shell thickness in several ways. Remote operability enables crawlers to be controlled from a convenient and safe ground position, without the need for costly scaffolding. The crawlers can be directed to the location that needs to be inspected, and most crawlers have the option to record data while they are moving and create a so-called ‘B-scan’. With speeds of up to 200 mm/sec. (7.9 in/sec), remote crawler inspection equipment can collect continuous shell thickness data much faster (at a higher periodic rate) than most other techniques. The benefit of continuously collecting data while driving is that the B-scan profile will show the smaller areas of the shell thickness variations that may be affected by corrosion; areas that may have been missed with spot measurements only. Inspecting with UT crawlers is even more beneficial if a dry-coupled method is used. UT measurements

generally require a couplant between the surface and the UT probe to transfer the ultrasound energy into the material. Some crawlers will use a water-path to accomplish this, while other crawlers use a dry-coupled method. The latter system uses a small supply of oil between the surface and a specially designed rolling probe. Another benefit of using remote inspection crawlers is that their scanning position is encoded. This information is often saved with the inspection data and helps to locate areas of interest post-inspection. It will also benefit the reporting of tank shell thickness distribution. With location information available, historic data can then be compared to see if any corrosion is forming and at what rate.

In storage tank roofs, remote ultrasonic inspection crawlers offer an advantage over typical manual inspection processes. For safety reasons, many asset owners do not allow workers to walk on tank roofs without knowing whether it is affected by corrosion and, sometimes roofs are not accessible at all for construction or other safety reasons. This restriction of access can prevent the inspection company from performing the recommended wall thickness measurements. A remote crawler enables inspectors to remain on roof walkways while deploying the crawler in the areas where the wall thickness measurements are required.

Using efficient softwareA further improvement in efficiency can be achieved after the physical inspection and data collection exercise has been completed through the use of stored data in specific IDM software, with the primary goal of creating semi-automated inspection reports. Tank inspections yield impressive amounts of data from different inspection equipment sources, which can be supplemented with photographs of areas of concern. It can be quite an intricate job to collate all of this data into a report. The use of IDM software can help make this task more efficient by providing tools to organise all of this data into a single view. IDM software is usually equipped with functionality and tools to conveniently gather and analyse the inspection data for a better overview of the asset and the resulting data from the inspections performed.

ConclusionIn a competitive world, asset owners want to increase the revenue generated by their tanks and assets by reducing downtime and keeping them in-service longer. To achieve this goal, inspections must be carried out as efficiently and as accurately as possible, enabling engineers to determine the best maintenance strategies. Modern inspection technologies play an important role in achieving these objectives. A combination of these technologies can offer a real understanding of the condition of assets.

Figure 4. Tank roof surface corrosion.

Figure 3. Remote-access tank shell crawler.

Summer 2018474

It makes sense to replace the risky manual tank cleaning methods that have been common for decades and that are still in use around the world today. A no-man entry automated closed loop

tank cleaning system not only offers greater operational and personnel safety, but also high

recovery rates of the hydrocarbons entrapped in the sludge that is cleaned out. Furthermore, no-man entry automated tank cleaning is usually much faster than manual cleaning methods, which means that tanks can be brought back into operation quicker. In short, the improved health and safety procedures applied to the operations, the decreased environmental impact, and the rapidly regained storage capacity speak for a safer and more efficient approach to tank cleaning.

Benefits for the tank ownerWith all the well documented advantages of no-man entry automated tank cleaning systems, why is manual cleaning still common practice at many sites?

As legislation and regulations are tightened, the quest for increased safety and efficiency, built into tank cleaning systems, never stops. Søren Hansen, Oreco A/S, Denmark, explains why.

Figure 1. A view of an operator programming Oreco MoClean® ATS operations.

48Summer 2018

The answer is usually that the immediate direct costs of applying manual cleaning methods can seem lower and decisions are often made without considering the overall financial impact for the tank owner. The commercial value of recovering entrapped hydrocarbons in the sludge is also sometimes forgotten, as it is often not part of the same budget. When cleaning the tank manually, the sludge is typically treated as waste to be disposed of, which can come at a high cost.

When safety comes firstWhile the benefits of the no-man entry automated tank cleaning system are clear in terms of resource utilisation, they are even more obvious when it comes to protecting the employees involved. When employees enter an oil tank, there is a risk that things can go wrong. Cleaning personnel do not always have the necessary qualifications or understanding of mandatory safety precautions.

Analysis suggests that up to 80% of accidents in the tank cleaning industry are the result of human errors. No-man entry automated tank cleaning systems substantially reduce the risks involved in the cleaning process. As such, it is unsurprising that both national and international legislators are presenting new legislative measures and strict directives regarding safety in tank cleaning operations.

Advantages of being fastMissing out on the commercial value of recovered hydrocarbons is not the only financial disadvantage connected with manual cleaning processes. Accidents and damage to equipment and property can slow down the tank cleaning process considerably and make scheduling difficult.

Automated no-man entry tank cleaning systems make it considerably easier to plan and predict tank cleaning operations, ensuring that operations are resumed quickly and utilisation of tank storage capacity is maximised. No-man entry automated closed loop tank cleaning systems are up to three to eight times faster than manual tank cleaning methods. This results in a smooth and manageable operation process and a reduced need for increased tank storage capacity.

Versatility at a new levelBlack oils, white oils, slop oils, petrochemical products, and a host of other products are kept in tanks at facilities all over the world. Different products need different cleaning fluids, which is yet another factor in favour of replacing traditional manual cleaning processes.

No-man entry automated tank cleaning systems allow a wide variety of chemistry and fluids of different temperatures, densities and viscosities to be used to achieve the best possible

Figure 4. A view of an Oreco MoClean ATS module before it is fitted onto a 20 ft container.

Figure 3. A view of an Oreco MoClean® ATS automated no-man entry tank cleaning system in operation.

Figure 2. A view inside an Oreco BLABO® automated no-man entry tank cleaning system.

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50Summer 2018

cleaning result. Therefore, the tank cleaning service provider will adapt to the actual situation and increase the efficiency with which the tank is cleaned and ready for operation again.

Nozzle technologyOreco A/S’s hydraulically driven, remotely controlled, and programmable Single Nozzle Sweeper® (SNS) is an advanced cleaning nozzle. It is approved to operate in Ex-zones 0 and 1, and it is accompanied by a drive unit with sensor technology to control position, speed, and direction of the nozzle.

In 2017, the company introduced its next generation, computer-controlled nozzle for aboveground storage tanks. The new solution, which has an ATEX Zone 0 certification, will provide users with further operational flexibility.

Furthermore, a new Rim Seal Nozzle will provide operators with versatility in executing tank cleaning operations.

Case studiesOreco’s no-man entry technologies have helped companies worldwide to achieve results that would not have been possible through manual cleaning processes.

One tank cleaning job at the VEBA terminal at Ras Lanuf, Libya, helped to prevent the desert from being contaminated with 22 148 m³ of crude oil. Instead, the terminal received almost US$4 million worth of recovered oil with the help of the use of BLABO® technology, which allowed the recovered oil to be pumped directly into an oil tanker. This system is designed for large-volume, difficult-to-clean oil tanks. The automated, mobile, and modular no-man entry oil tank cleaning system is targeted at crude oil, heavy fuel oil (HFO) and other types of black oil, and offers a closed loop cleaning system, which reduces the impact of tank cleaning on the

environment and has more than 95% hydrocarbon recovery.

The BLABO system was also imperative for BP-Gelsenkirchen GmbH (Ruhr Oel) due to strict legislation in the Ruhr district, Germany. A partnership between Ruhr Oel, Maersk Contractors and Oreco resulted in a tank cleaning procedure that complied with both local regulations and Ruhr Oel’s own practices. The high hydrocarbon recovery represents both an environmental improvement, as disposal of sludge is reduced to a minimum, as well as cost savings, as nearly 100% of the hydrocarbons are recycled.

For Canadian company, Orion Tank Solutions (OTS) it was important to improve safety in tank cleaning without compromising productivity and cost efficiency. OTS originally had a staff of 20 to

30 people for manual cleaning. Oreco’s MoClean® ATS system helped to eliminate more than 90% of dangerous entries into the tanks and recover more than 95% of the hydrocarbons in the sludge instead of driving sludge to landfill. MoClean® is a fully automated no-man entry system for small and medium sized tanks containing white oil, diesel, and petrochemical products. MoClean ATS combines SNS and MoClean/BLABO technology, as well as a vacuum tank fitted with an oil/water separator. The system is self-sufficient for both air and power for the cleaning process, thus eliminating the need for the tank owner to supply these utilities.

The future is automatedMore than a century after the construction of the first crude oil tanks, manual tank cleaning is still common practice within the industry. With stricter regulations, however, it is a matter of time before the more efficient and environmentally-friendly automated no-man entry technologies will prevail, as they offer the following advantages:

Safety – no-man entry dramatically reduces the risk for personnel compared to manual cleaning processes.

Efficiency – automated tank cleaning is reliable and predictable, which makes it easier to schedule the cleaning.

Speed – an efficient and automated tank cleaning process can do the job three to eight times faster than manual cleaning methods.

Environment – in a closed loop tank cleaning system, hydrocarbons are recovered and leave minimal waste for further disposal.

Economy – the commercial value of the recovered hydrocarbons, the reduced cost for sludge disposal, and the ability to get a tank back in operation quickly, makes the no-man entry automated system advantageous compared to manual cleaning operations.

Figure 5. A view of the MoClean® part of the MoClean ATS leaving the workshop.

Summer 201851

F uel farms at airports contain bulk fuel storage tanks, truck racks and other equipment, similar to a commercial tank farm or marketing terminal. However, there are complexities to managing an

airport fuel farm that make control and automation critical to ensure an effi cient and safe operation. All fuel farms have a control room, and with proper automation, operators can monitor all aspects of the fuelling system.

There is a wide range of concerns for those managing these fuel farms. Ensuring overall safety is always paramount, but there are unique challenges at each location that impact day-to-day operations. One of the biggest challenges faced by operators is trying to manage and integrate the disparate systems utilised across the

fuel farm. Most of these systems are procured and installed over time by different vendors and manufacturers, which compounds the issues even further. In addition, some operators do not have access to accurate real time inventory information that would enable them to make more informed operational decisions about fuel movement and storage. They also express concerns around managing required pressure and fl ow volumes for on-demand hydrant systems due to inconsistent pump run time and uneven wear and tear on those pumps. Another issue is the lack of integration between fuel management systems and the emergency fuel shut-off (EFSO). This can result in extended downtime for the hydrant system while the issue is located.

Derek Blagg, Varec Inc., USA, discusses best practices for automation at airport fuel farms.

52Summer 2018

The importance of movement tracking systemsProduct movement tracking is an essential component of any fuel farm automation system. A movement tracking system can automatically track fuel movements based on valve position, pump status or user command. Beginning level, end level, transfer set points, volume, time stamps, and other critical information is stored in the movement transaction for use in reconciliation and reports. With a movement tracking system, every time a valve is opened or closed on a tank, the product movement is tracked. Therefore, it is easy to view which tank received or issued fuel and how much was moved. If there are discrepancies, they are identifi ed immediately and the process to determine why can begin.

Another benefi t of having a movement tracking system is the ability to incorporate a fuel accounting system to track ownership and perform reconciliation. When fuel is delivered to the fuel farm, the operator receives a bill of lading (BOL) denoting how much fuel was delivered. The amount refl ected on the BOL is used as the quantity

received in the inventory accounting system. Fuel typically leaves the fuel farm by hydrant system or load racks and is recorded on fuel tickets as it is loaded onto aircraft or into tanker trucks. Sometimes, the reconciliation and closeout process indicates a variance because the calculated book inventory, based on incoming and outgoing product, does not match the measured physical inventory. This variance can be a result of any one or a combination of issues. For example, what was recorded as received from the BOL may not match what was physically received. Product movements at the hydrant system or load rack could be recorded incorrectly or entire transactions could be missing due to lost tickets. The automatic creation of transactions by the movement system captures real time

data and is critical in the investigation of variances.

Pressure and flow vs pressure then flowAt most airports, the current system pressure is typically only factored into the equation when it is time to initiate the start of the fi rst hydrant fuel pump. Each additional pump then starts or stops based on fl ow rate. This is often problematic because the system is starting or stopping a pump without taking the current system pressure into consideration. Starting a pump based only on fl ow, without regard to the current pressure, could cause pressure to rise above the recommended operating threshold.

Alternatively, stopping a pump without regard to pressure could produce a sudden drop in pressure and bring the system down to alarm limits, forcing a quick start on the next pump. Augmenting the programmable logic controller (PLC) to take into account both pressure and fl ow reduces quick starts and stops that cause unnecessary wear and tear on pumps.

Achieving optimal pump performanceWith hydrant systems, fuel pump performance and maintenance are major concerns for most airport fuel farms. It is common for fuel control systems to utilise a lead-lag methodology for managing when fuel pumps start and stop. In these systems, a lead pump is designated and then additional pumps are started as needed to provide demand at the desired fl ow rate. As demand and the fl ow rate decreases, the most recent pump started will be the fi rst pump stopped. This continues throughout the day, based on demand, until only the lead pump remains on. Typically, the pump designated as the lead only changes after a preset amount of time passes, or when all pumps have stopped,

Figure 1. Airport fuel storage tanks and hydrant pumps.

Figure 2. EFSO terminal map showing active alarm in, and resulting isolation of, Zone 2.

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then the next pump in sequence becomes the lead pump. This method results in some pumps having long run times and others having short cycle run and stop times.

Using lead-lag, the pumps in the middle of the sequence tend to be started and stopped the most. As such, the pumps are unable to properly rest between cycles. For optimal performance, pumps should have a long run-time, followed by a cool down period. Alternatively, the fi rst-in, fi rst-out (FiFo) system does not have a dedicated lead pump. Instead, pumps are rotated through as demand increases and decreases, resulting in more even run times across all pumps. This methodology requires more complex PLC coding, but the benefi ts to the overall pump system are high. FiFo spreads the run times across all pumps in a more distributed manner, thus reducing the wear and tear experienced in a lead-lag system. This helps improve overall performance while also reducing maintenance costs and pump downtime.

EFSO system integrationThe EFSO system at an airport is one of the most important aspects to running a safe hydrant fuelling operation. There are EFSO buttons near the hydrant system throughout the airport and fuel farm. When an EFSO button is pushed, the pump system providing service to that section shuts off immediately. At many airports, when an EFSO button is pushed, operators are not able to quickly identify where the shutoff took place. Teams across the airport race to check each panel to determine which EFSO button was hit and why. In the meantime, the hydrant system supplying fuel to specifi c areas, or sometimes the entire airport, remain shut off. This can cause signifi cant issues, especially at large airports.

When the EFSO system is integrated into the hydrant control system, tank farms can better isolate and manage EFSOs. In an effective integration, there are a series of controllers in the fi eld bringing all the EFSO inputs into a main system in the control room. The human machine interface (HMI) for the EFSO system displays the entire layout of the airport, including each EFSO button location and the status. When a button is pushed, an alarm sounds in the control room and the operator can easily locate which EFSO button was initiated by looking at the monitor. If the hydrant system layout allows, this integration can also isolate the

shut off to only those terminals or gates affected by the button pushed, meaning the rest of the airport and hydrant system can continue to operate as normal.

ConclusionThis article outlines some of the recommended best practices for aviation fuel farm automation, and should not be considered a comprehensive list of all possible automation confi gurations. When considering an automation upgrade, the design team needs to understand the current infrastructure, goals and budget. Finding a strong partner to help execute the automation is critical. Where possible, it is advisable to select a single partner that can integrate all automation, or can support the entire system once a project plan has been developed.

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Summer 2018555

T he tank storage business has some traditional restrictions that infl uence operability. Storage terminals act as a buffer to complex logistics supply chains and their operations are

continuously challenged by scattered supply and demand of raw materials and fi nal products.

To ensure profi tability, storage terminals must effi ciently deliver products to the right location at the right time. This must be done with operational fl exibility to ensure fi nancial control. As legislations tighten, environmental awareness rises and customer requirements evolve, terminals must store and move more products quickly and safely.

Inventory control and capacity optimisation are essential to remain competitive. In a challenging environment, production automation must be able to respond to increased demands from multiple directions.

Circular economy, sustainability, carbon reduction, changing legislationWaste and residues form a continuously expanding raw material source for recycling industries. Digitalisation has generated new solutions and opportunities to utilise materials previously seen as waste. However, a circular economy requires traceability of raw materials throughout the supply chain. Inconsistent and distributed material sources will create new challenges for the production chain. Information about the quality and quantity of batches must be available from the upstream sector to ensure effi cient and appropriate collecting and further processing of waste.

Robust, autonomous systems for remote monitoring of storage tanks and containers are needed. A tank sensor system has to be easy-to-install and work accurately and reliably in any location and different environments. The communication channels between tanks and their centralised management

Tomi Lahti, Lauri Saurus and Niko Hellgren, NAPCON, Finland, report on how Industry 4.0 is driving efficiency and security

improvements in tank and terminal operations.

56Summer 2018

systems must work fl uently and effi ciently, allowing the centralised management to reliably relay the information to enterprise operational systems.

Industry 4.0Industry 4.0 is a vision of how different players in the process industry will work in a more customer-driven, automated, fl exible and effi cient way. It enables new, more productive processes to be built by considering them from multiple viewpoints, including production, procurement, sales and logistics.

Parts of Industry 4.0 already exist, while others are still in the development phase and will likely be realised in the longer term. This causes uncertainty around what is already available for investment, and what is not worthy of attention yet. Existing technologies can already enable digitally-controlled small delivery lots with transparency and excellent response capability.

Instead of relying on ad hoc solutions focused on transmitting information despite the limitations of the technology, modern, Industry 4.0-enabled applications embrace the possibilities of uniform communications.

Ease of analysis, experimentation, and synthetisation of collected data presents new, previously undiscovered knowledge and possibilities. As an example, equipping all related systems with standardised interfaces enables data

analysts to easily connect their tools to multiple sources of data without the additional technical and cognitive overheads of dealing with a wide variety of protocols, data formats, and service interfaces.

Distributed industrial data gathering systems, composed of multiple parties and vast quantities of data, face security-related problems common to distributed big data systems: data integrity, availability, and confi dentiality. Finding the balance between the confi dentiality of communications and the system’s availability to all desired parties is critical to successful integration. Industry 4.0 seeks to mitigate collaboration-related issues by recommending that all systems communicate in a standardised fashion, specifi cally via OPC Unifi ed Architecture (OPC UA).

OPC UAOPC UA is the chosen communication and information model for Industry 4.0. It is not a new protocol and utilises established industry best practices. OPC UA can be briefl y described as “a platform independent service-oriented architecture that integrates all the functionality of the individual OPC Classic specifi cations into one extensible framework.”1 It emphasises open transport, high levels of security and a more complete information model than the original ‘OPC Classic’. OPC UA provides fl exible and adaptable mechanisms for moving data between enterprise-type systems and controls, monitoring devices and sensors that interact with real world data.

OPC UA specifi es a service-oriented communication protocol and an extensive information modelling system that are independent of platform and programming language. This ensures that all data can be seamlessly transferred between different systems, from small embedded devices to large mainframe server. In addition, OPC UA has built-in security features that ensure data integrity and provide access management. Audit logging also ensures the traceability of operations.

A recent ARC Advisory Group report acknowledges the important role that OPC data connectivity standards play in control automation today and in future industrial IoT (IIoT) and Industry 4.0-based solutions: “IIoT-enabled edge devices embedded with OPC UA [are] being leveraged as an ‘asset gateway.’ This can help organisations maximise their return on

assets (ROA) by helping ensure that their automation investments are scalable, future-proof, adhere to open standards, and integrate with existing assets to avoid having to ‘rip and replace’ current automation infrastructure.”2

For vendors, there is a certifi cation programme by OPC UA Foundation that is able to prove that certifi ed products have been tested in a certifi cation laboratory accredited by OPC Foundation, and have met or exceeded the multiple requirements related to compliance, interoperability, robustness, usability, and effi ciency.

The benefi ts of using certifi ed products include faster mobilisation and confi guration, proven reliability and interoperability, as well as minimal integration risks.

Figure 1. Aerial view of an oil refinery.

Figure 2. Common process industry information highway.

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SecuritySecurity has traditionally been an afterthought when it comes to protocols designed for industrial communications. In the era of small networks enclosed in guarded industrial facilities, this was a viable approach. However, the distributed nature of modern industrial networks presents new risks that need to be considered in the development and management of technical solutions.

The seemingly trivial approach to mitigating these risks would be obfuscation by using proprietary or custom-made protocols, interfaces, and security solutions. While the ‘security by obscurity’ approach is viable against unskilled and opportunistic attackers, it is ineffective against targeted attacks by capable individuals and organisations.

In the era of interconnected systems, organisations can improve their assurance of protection by following open standards and industry best practices, applying proven security solutions, and identifying the critical role of security as a process in connected systems.

Tank and storage solutionsTraditionally, tank farms have been located near harbours and refi neries in order to reliably verify and maximise the utilisation rate of components across the whole production chain. Reliable data synchronisation between storage locations and information systems is essential, and close proximity of the two makes reaching this goal easier.

Collecting scattered raw materials at specifi c times generates additional challenges for tank and storage systems. Cost-effectively combining multiple small fl ows requires effi cient logistics. The tank must be aware of its contents and the anticipated discharge time, and communicate that information accordingly, so that logistics can be optimally arranged for further processing.

In both cases, the easiest way to implement or modernise process tracking is to transfer the data wirelessly directly to a cloud service via Industry 4.0 standard OPC UA communications. Instead of using unprotected legacy communication protocols across a Wide Area Network (WAN), IIoT edge solutions offer modern communication techniques that are designed for secure and effi cient network communications.

One of the main business differentiators presented in the Industry 4.0 initiative is the horizontal integration across company and business area borders. This topic is also important in the case of distributed resource gathering via smart tanks. Different parts of the tank network may be owned, managed or maintained by multiple organisations, with different goals and policies.

To ensure collaborating parties’ trust in the distributed system, it is essential that the system’s management and utilisation processes are transparent.

A major obstacle for legacy systems that prevents cross-organisational collaboration is the heterogeneity of devices, networks, and communication protocols. Utilising standardised data models and communication protocols enables faster and more predictable integration of different manufacturers’ devices. Open, clearly defi ned technologies also increase the transparency and verifi ability of systems, and lower the threshold to starting new collaborations.

Modern communications combined with appropriate management processes enable direct digitalisation of tank operational management. From the cloud, data can fl ow to plant automation systems, Enterprise Resource Planning systems (such

as SAP), or other relevant management systems related to the use case. A central cloud solution allows smooth storage capacity changes as storage units can be added to the system (or removed from it) when needed.

Seamless production chain Accurate, real time inventory can be seen as part of a wider production optimisation context. NAPCON offers solutions for import/export logistics, production site storage area design and logistics, as well as optimisation of site location.

The company has successfully gained the OPC UA certifi cation for its big data product, NAPCON Informer, which consolidates the company’s product family to be OPC UA compliant.

References1. OPC Foundation, https://opcfoundation.org/about/opc-technologies/opc-ua/

2. RESNICK, C. and CLAYTON, D., ’OPC Technology Well-positioned for Further Growth in Tomorrow’s Connected World’, ARC Advisory Group, (10 January 2018), https://opcfoundation.org/wp-content/uploads/2018/02/ARC-Report-OPC-Installed-Base-Insights.pdf

Figure 3. Indicative process industry digitalisation example with NAPCON solutions.

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T hief hatches are installed on the top of low pressure and atmospheric tanks in both the oil and gas, and chemical industries, as well as others, to allow access to the tank. They can

be used to take samples of a tank’s contents and determine the tank’s level. They also protect the tank from over pressure and excessive vacuum.

The thief hatch acts as a pressure safety device on the tank. When closed and latched, two separate spring-loaded seals protect against excessive pressure or vacuum. If excessive pressure builds up in the tank, the hinged hatch cover will break its seal and lift, allowing the pressure to escape to the atmosphere. When the pressure or vacuum is reduced to the setpoint, the seal is reseated by sealing the tank.

When a thief hatch closes, either due to gravity or a worker closing it, the hatch may not seal unless it is

firmly latched. This allows vapours in the tank to leak into the atmosphere, which can violate regulations.

To avoid stiff penalties and protect the environment, Great Western Oil and Gas Co. (Great Western) installed wireless thief hatch monitoring systems on its oil tanks in the Denver-Julesburg (DJ) Basin in Colorado, US. The DJ Basin is a 70 000 square mile area in Northeast Colorado, Southeast Wyoming and Southwest Nebraska. More than 52 000 wells have been drilled in the basin and Great Western has more than 600 operating wells there, producing nearly 13 800 bpd of oil.

Tough regulationsThe State of Colorado has some of the oil industry’s toughest environmental regulations. The Colorado Department of Public Health and Environment requires

Vance Ray, R3 Automation, USA, explains how wireless sensing helps producers and facilities cut emissions and comply with tough regulations.

60Summer 2018

monitoring of thief hatches on oil and water tanks to prevent the release of methane and volatile organic compounds to the atmosphere. The XII.E.4.d regulation reads: “For all atmospheric condensate storage tanks, the owner or operator shall check for and document on a weekly basis that the thief hatch is closed and latched.”

To enforce the regulation, Colorado inspectors regularly check for emissions from leaks and open thief hatches with thermal scopes and infrared cameras. The state inspectors document any open thief hatches, and compare their records to the producers’ by time and location. If the producer can confirm the thief hatch was open, perhaps for maintenance or sampling, when the inspector found it open, then there is no problem and no penalty. If the producer cannot confirm why the hatch was open from its records, penalties and fines are assessed. Penalties are severe, with fines reaching up to US$15 000/d per open thief hatch, with many facilities having many thief hatches per site.

Oil producers across the US fear that the US Environmental Protection Agency (EPA) will soon adopt a similar regulation, and are searching for ways to monitor their thief hatches in a cost-effective manner.

Inside thief hatchesA thief hatch is a rugged device that is designed for harsh environments and handling by ‘less than gentle’ users. Made from cast aluminium, thief hatches are used on fibreglass and steel tanks in the oil and gas, chemical, and other industries. Most tanks used in these heavy industry applications come with a thief hatch (Figures 1 and 2).

The thief hatch has a latch that locks the lid closed. If an operator opens the hatch to check tank level or take a sample, he or she lifts the latch, raises the lid, performs the necessary function, and closes and latches the hatch. If the lid is not properly latched, the tank will not be sealed and will, therefore, vent to atmosphere. Colorado wants to eliminate the unnecessary release of methane and volatile organic compounds (VOCs) into the atmosphere from production facilities.

Monitoring thief hatchesR3 Automation has been working with Emerson Process Automation and several oil and gas companies to develop a thief hatch monitoring system. Rosemount 702 discrete WirelessHART® transmitters can be installed on existing thief hatches and tank batteries to ensure the hatches are closed and latched (Figure 3).

The concept is fairly simple: a switch at the latch detects when the latch is closed (Figure 4). The switch is non-powered, has no magnets, is easy to install on new or existing thief hatches, and no hot work is required. The switch is wired to an intrinsically safe wireless transmitter. The

Figure 1. A thief hatch has a lid that can be opened manually. The latch (upper left) keeps the lid closed and the tank sealed when closed.

Figure 2. An unlatched thief hatch allows volatile gases to escape.

Figure 3. A Great Western thief hatch fitted with a WirelessHART monitoring system. When the latch is open, the transmitter sends a signal to the facility’s controller so it can be logged or an alert can be sent out.

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Signatory Union Contractor

A T C“A wholly-owned subsidiary of Associated Construction and Engineering Inc.”

23232 Peralta Dr.—Ste 109 | Laguna Hills, CA | 92656 (949) 299-5766

ASSOCIATED TANK CONSTRUCTORS, INC.

www.a-t-c-inc.com

62Summer 2018

battery-powered transmitter is also easy to install. It requires no power wiring and no signal wiring, so it can be mounted in any convenient location on top of the tank. To conserve battery life, the scan rate is once per minute, which is more than sufficient for this monitoring application.

The estimated cost for installing a WirelessHART thief hatch monitoring system on one tank battery (eight tanks) was calculated to be approximately US$8300, including switches, wire, terminations, transmitters and labour.

The cost per tank can be substantially reduced if latches on a tank battery are wired in series to a single WirelessHART transmitter. This type of installation will indicate if one of the hatches in the bank is open, but not which one. In practice, once alerted, an operator would be sent to site to determine which hatch needs to be fully closed and latched. This method of monitoring complies with regulations, is practical, and allows quick response to any open hatch conditions.

If a tank farm does not already have a WirelessHART infrastructure, the cost of a gateway must be added. To date, R3 Automation has installed

its thief hatch monitoring systems on more than 100 tanks at five different oil producers in the DJ Basin.

Tank monitoring in ColoradoAt Great Western’s tank farm in Colorado, R3 Automation’s thief tank monitors were installed on two water and 12 oil tanks. The tank monitoring system is arranged in banks, as shown in Figure 5. At the top of the image, oil tanks 2, 4 and 6 are wired in series to channel 1 of the transmitter. Water tank 1 and oil tanks 1, 3 and 5 are wired in series to channel 2 of the transmitter. Meanwhile, at the bottom of the image, oil tanks 7, 8, 10 and 12 are wired in series to channel 1 of the transmitter. Water tank 2 and oil tanks 9 and 11 are wired in series to channel 2 of the transmitter.

The wireless transmitters send data to a gateway mounted on a DIN rail in the facility’s main control room.

In addition to the thief hatch monitors, the tank farm has 30 more Rosemount level switches, temperature transmitters and pressure transmitters mounted on the tanks to create a comprehensive tank monitoring system. The data from all transmitters goes to the WirelessHART gateway, which is hardwired to a TotalFlow remote terminal unit. The system is programmed to monitor the thief hatch signals and report any open hatches to the operators.

Because the tanks are wired in four banks, operators can narrow down an open hatch condition to four tanks at most, making it quick and easy for field technicians to locate the offending hatch and latch it closed.

ResultsThe monitoring system alerts operators to open hatch conditions within 1 min., allowing quick resolution of any problems. Field technicians do not need to periodically monitor and document the status of thief hatches manually. Instead, they only need to respond to an open hatch alert. This reduces manpower requirements for monitoring thief hatches, and demonstrates that Great Western is employing an efficient technology to protect the environment and comply with regulations.

In addition to the tanks in Colorado, R3 Automation has installed its thief hatch monitors at two other

Great Western tank farms. At the time of writing, none of the thief hatches have been detected open by the State of Colorado because the facility can react quickly to open hatch conditions.

SummaryAlthough Colorado is the only state to issue tough regulations for monitoring thief hatches, such regulations are probably coming from the EPA, or from individual states. The R3 Automation thief hatch monitoring technology is a cost-effective solution to avoid fines, reduce product loss to the atmosphere, and cut emissions.

Figure 4. A simple switch (yellow) detects if the latch is open or closed.

Figure 5. Great Western’s tank farm has WirelessHART thief hatch monitors on two water and 12 oil tanks.

Summer 2018636

W ireless remote monitoring networks provide industries with the capability to automatically track and control fi eld assets. Increasingly, wireless sensor systems can monitor tank levels (and other

parameters) and use radio technology to transmit the data to control centres. These wireless systems prove cost-effective by eliminating the need for wiring and trenching, especially in applications covering long distances. This is particularly the case for tank farms.

However, not all wireless remote monitoring systems are the same. In some cases, the radio network limits the control system’s effectiveness in certain terrains. The following is a comparison of the three basic radio network schemes:

A 1:1 system is the simplest network. The most basic configuration of this system is a level switch wirelessly controlling a remote pump/valve. Essentially, this system replicates the sensor signal (a switch) at some other location. For a simple, unmonitored tank application, this type of system can be ideal. It has the control element but does not have any remote monitoring or historical data capabilities.

The next level of sophistication is a star system featuring multiple wireless nodes that send sensor data into a single point. Because the system involves multiple sources of data, the data must be addressed so its source can be identified.

Mesh networks are self-forming and self-healing networks where messages are passed from device to device until they arrive at a central point, called a gateway. While similar to the star system, mesh networks improve the robustness of communications. Ranges can be greatly extended and obstacles that might impede transmission can be detoured. When hills, buildings and other obstructions block a radio signal, a star system becomes impractical. The use of long-range radios, coupled with mesh networking technology, resolves the problem faced with obstacles, providing the installer with options to connect every node to the gateway.

Mesh network configurationMesh networking is a wireless technology that permits many wireless devices to self-confi gure into a web-like structure. Each

wireless node moves data in a peer-to-peer fashion (from one node to another) until the data reaches the gateway. The route taken will depend on the situation, as a good mesh network will pick the best route from each node to the gateway.

The gateway is a data concentration point typically connected to a local programmable logic controller (PLC) or to an internet device such as a cell modem (Figure 1). The range can be greatly extended due to the multiple ‘hops’ between the remote monitoring and control points and the central gateway.

Three critical attributes of a well-designed mesh network include:

The data moves in ‘hops’ from device to device as it travels from one point in the mesh to another. This hopping permits lower power data transmissions and the placement of devices over a larger area, leading to increased coverage and reduced installation problems.

Data may also take alternative paths to its ultimate destination, ensuring robust operation should a node become lost. Routing paths are constantly adjusted by the system to ensure optimal paths to the gateway.

Nodes self-install into the network, with no configuration required.

Most mesh networks use three types of devices:Gateway – the interface between the wireless system and another network (often the internet or computer). It often provides administrative functions to manage the mesh. The gateway is the ‘centre’ of the wireless system.

Routing nodes – these are standard nodes that connect to devices (sensors, actuators or computers). In addition to monitoring and/or controlling the device, the routing node participates in the mesh network. Routing nodes are usually line/solar powered, but battery operation is practical in some cases.

Client nodes – clients perform a subset of the functions of a node. Typically, they can send and receive data from the device to which they are attached, but do not participate in the mesh. Clients are usually battery powered as the routing capabilities can be power hungry tasks.

Scott Keller, SignalFire Wireless Telemetry, USA, examines how self-configuring mesh networks address the challenges associated with the wireless monitoring of

outdoor tank level applications.

Crossed signals

64Summer 2018

In outdoor environments, a wireless system may spread over many square miles. When hills and buildings obstruct a radio signal, a mesh network allows wireless nodes to utilise neighbouring nodes to relay or ‘hop’ messages to a central location (gateway) (Figure 2). Each node determines the ‘best path’ to the gateway, based on the information derived from the nearby nodes. The intuitiveness of the nodes allows the system to automatically adjust to changes so that the data can fi nd and take alternative routes, when necessary, to its ultimate destination.

Mesh network at work in a tank level applicationThe self-confi guring capability of the mesh network proved essential in the following tank level monitoring application that required frequent network changes.

In the original confi guration of a network supporting the wireless remote monitoring of tank levels, eight short-range wireless nodes were measuring tank levels and checking into a gateway approximately 1000 ft away. The hydrostatic pressure sensors that were monitoring the tank level, as well as the wireless nodes, were installed at ground level. However, four of the nodes were on the ‘wrong’ side of the tank battery and had

to transmit a signal ‘through’ the tanks in order to deliver data to the gateway. This confi guration worked well until a tanker truck parked between the tanks and the gateway. Once the tanker was in the way, a few of the nodes on the far side of the tank battery could not directly reach the gateway.

The solutionThe problem was solved by solar powering one of the nodes that was located on the near side of the tank battery, which allowed it to forward messages automatically, if and when it was necessary. When the truck was not present, all nodes were able to check into the gateway directly. However, when the truck came back to offl oad oil and again blocked some of the nodes on the backside of the tank battery, those nodes would automatically reroute (Figure 3) their message path through the always-on node on the front. Once the truck moved away, those nodes reverted back to direct communications with the gateway.

Without the mesh networking capability, the wireless remote monitoring and control system would not work under varying circumstances. No confi guration or setup is needed with a true mesh system as it operates automatically, freeing the installer of complicated radio frequency (RF) concerns.

The outdoor challengeIn outdoor applications that monitor assets such as tank levels, operators often do not have control over the location of wireless nodes or what might be placed between each node and the gateway. In this instance, having a robust mesh capability can help with this problem as the unique network enables clever monitoring schemes.

For example, when monitoring assets that are located outside, it is unlikely that all wireless nodes at each site will be able to reach a central gateway. To combat this, the placement of a high power, long-range node along with low powered nodes that can operate in hazardous areas will (automatically without confi guration) connect to the gateway through the long-range node. The use of a mesh network allowed the wireless nodes to utilise neighbouring nodes to relay or ‘hop’ messages to a central location.

ConclusionMesh networking overcomes the limitations experienced by older telemetry systems. It provides the power and stability needed for reliable data transfer, especially for widely dispersed assets (up to three miles point-to-point) that transfer simple data in small volumes. The use of long-range radios addresses the problems with hills and buildings causing obstructions, while the self-confi guration feature eliminates the burden of a reconfi guring system as changes are made to the sensor network.

Figure 3. When a truck blocked radio nodes from directly communicating to a gateway in a tank level monitoring application, a mesh network enabled those nodes to automatically reroute their message path.

Figure 2. A mesh network permits many wireless devices to self-configure into a web-like structure. In a wireless sensor control system, data moves from one radio node to another or between a node and an external connection (gateway).

Figure 1. Wireless sensor control systems consist of nodes that integrate with different sensors to send data to a gateway, where it is transferred to a PC, PLC, or other control system.

Summer 2018656

O rganisations across the globe are looking to the Cloud to provide protection and ensure the safety and integrity of their facilities. This search has been brought about by new regulatory burdens, as well as

a shift in organisational culture toward a safety-minded workforce. The challenge has been finding the right-sized solutions to empower this workforce. The solutions need to manage the growing mountain of safety-related data, without adding additional workload to the front-line operations and maintenance staff. In addition, the correct solution must deal with constrained IT and information management resources.

In the past, the answer to this type of increased regulatory and organisational change was to develop procedures for

Jeremy M. Lucas, Mangan Software Solutions,

USA, discusses the development and implementation of

safety lifecycle management point-to-point testing in the

Cloud for midstream oil and gas origination, tank storage, and

delivery terminals.

66Summer 2018

capturing the initial data, typically on paper forms. This documentation was then filed or stored electronically in either local record storage or an electronic document management system. Translation to digital records added data entry and management requirements, as well as IT information management systems and support. All of this required annual compliance training and manual scheduling of activities, because they were not part of a holistic system designed to manage and interconnect information or data being collected. Finally, deeper complexity was then added with the retrieval of information when required by regulatory audits, as well as leadership level key performance indicators (KPIs) to track the compliance of the organisation as a whole. This detailed, high level reporting could take weeks or months to determine the overall status of an organisation’s compliance to their own documented procedures.

The good news is that with complete Cloud-delivered solutions targeting safety lifecycle management (SLM), data entry and information management is no longer a burden and reporting takes

Figure 1. An SLM-P2P home dashboard.

Figure 2. A colonial pipeline system map.

seconds, rather than days, to complete. This new information is now actionable insight that can be leveraged across the organisation instantly on any device or platform.

Examining the case of point-to-point supervisory control testing, validation and checkout as part of US-PHMSA 49 CFR 190 – 199 for liquid petroleum and natural gas pipeline operators, facility operations and maintenance staff are required to test and validate safety related alarm (SRA) data points that monitor and control facilities on a fixed annual, or semi-annual basis. These tests and results must be documented and available for discovery by regulatory inspection and audit.

PHMSA control room management states: “The requirement is to verify all safety-related points in the SCADA system. This would also include calculated (software generated) points that are safety-related. Safety related points often, but do not necessarily, have alarms associated with them. Examples of points that may be considered safety related (and therefore would need to be verified when changes are made to field equipment or SCADA displays) include, but may not be limited to: status of main line valves, mainline pressures and flow rates, tank levels, station in local control, personnel in normally unmanned station, station inlet and discharge pressures, pump/compressor status, leak detection, pressure regulator inlet and outlet pressures, PLC/RTU communications status, emergency shutdown status, odorant alarms, composition alarms, such as H2S and water content, filtering equipment levels-scrubbers, flame, gas and vapour detectors, power supply indications, security monitoring."1-3

ImplementationFor a single facility, conducting, documenting and managing point-to-point tests, using traditional paper, spreadsheets, or document management toolsets may be a simple exercise. However, many organisations have tens or hundreds of facility locations and a multitude of users requiring simultaneous access to this data. As each facility is added, the information management debt grows. In addition, the complexities with disparate control systems and control schemes can introduce even greater difficulties to manage a consistent set of data points for each facility. Naming schemes for tagging, alarm descriptions and devices change and need to be accounted for as new assets. Lastly, all of this data will need to be interconnected across regional or even global physical locations. How is it possible to bring these technical challenges, as well as the operational goals, into alignment with technology?

In November 2016, Mangan Software Solutions began a case study with Colonial Pipeline Co. (CPC), one of the largest refined petroleum pipeline companies in the US. The case study deployed a

Summer 201867

Cloud-based SLM point-to-point test management software across CPC’s refined products pipeline, with over 300+ physical asset locations.

The stated goals of the project were to: Provide a Cloud-based system that removes

operations burden of duplicate data entry. Provide a single simplified solution that reduces

training requirements. Manage reoccurring test schedules for each SRA

data point. Increase overall organisational test compliance. Fully integrate with the organisation of the

existing IT infrastructure. Mirror the existing operations and technical

procedures that are in place.

To accomplish these goals, an initial assessment of the existing paper and digital data entry methods and processes was evaluated. These processes were simplified and streamlined with an all-digital Cloud-based system designed around SLM. Site operational data and control system data points were imported and mapped against a standard set of data field criteria. Additionally, reporting, event schedule, and metrics were set for each type of SRA and device. Finally, procedure and device type mapping was completed to ensure standardisation across all sites and to provide immediate familiarity with the subject matter to ensure system adoption. The result is a point-to-point testing system that, while simple in its design and function, can effectively manage a vast data set, and provide an information base for growth across the safety lifecycle needs for the organisation.

Development of technology and processWith increased scrutiny over elements related to control room management (CRM), point-to-point documentation processes and reporting have become a focal point when dealing with inspectors. Previously, CPC used a paper form that had to be printed out, filled in, scanned back to a PC, loaded to SharePoint, and then various fields completed to allow for searching at a later date. This process then migrated to a word document e-form that had similar restraints but reduced overall workload.

Leveraging a Cloud-based technology provides more of a ‘one-stop shop’, allowing for easier assignment of point-to-point tasks and completion based on required maintenance. The documentation went from a manual process that left opportunity for numerous errors and was nearly impossible to research historical data, to one that is more streamlined and provides direction for upcoming required testing, as well as historical records that are searchable and capable of performing analytical reporting and research.

The transition from the age of paper and pencil to Cloud technology may seem very complicated, but in reality the change is less difficult and more

rewarding. The reduction in time of data input and analysis, documentation and retention, and tools that provide fully functional prescriptive due dates with charts as well as notifications, provides a company with significant time to focus on other tasks and operations.

The continued adoption and integration of data centric information for this system will be ongoing. Some areas of future expansion include safety critical and alternate set point management, as well as integrated historical monitoring of events for safety trip and set point deviation.

ConclusionAs organisations continue to evolve SLM practices to meet and stay ahead of regulatory and organisational challenges, so too will technology and data management methodologies. By deploying right-sized Cloud-based data management systems, information can be shared across a diverse landscape of systems and devices that will help drive adoption of policies, procedures and compliance. The true benefit of a Cloud-based SLM approach is that it allows organisations to quickly and effectively put safety first without compromising operations or maintenance effectiveness.

References1. Ecfr.gov, CFR Title 49 - Subtitle B - Chapter I - Subchapter D

- Part 192.631 Control Room Management [online], (2009), available at: https://www.ecfr.gov/cgi-bin/text-idx?SID=e7ca99c974e6e1f85cb9a4707f0052a4&mc=true&node=pt49.3.192&rgn=div5#se49.3.192_1631, (accessed 21 July 2017).

2. Ecfr.gov, CFR Title 49 - Subtitle B - Chapter I - Subchapter D - Part 195.446 Control Room Management [online], (2009), available at: https://www.ecfr.gov/cgi-bin/text-idx?SID=e7ca99c974e6e1f85cb9a4707f0052a4&mc=true&node=pt49.3.195&rgn=div5#se49.3.195_1446, (accessed 21 July 2017).

3. PHMSA.gov., PHMSA Control Room Management FAQ - Section C - 01 - Is point-to-point verification required [online], (2017), https://primis.phmsa.dot.gov/crm/faqs.htm#c, (accessed 21 July 2017).

Figure 3. An SLM-P2P test entry form.

Summer 2018 68

Miriam Wennberg, Connect LNG AS, Norway, in collaboration with Gas Natural Fenosa, Spain, introduces a transfer solution that can help to make LNG accessible to a number of locations where it was previously not deemed feasible.

Summer 2018696

Initially, gas was a byproduct from the gasifi cation of coal to produce coke. As such, the original gas value chain was not based on methane, but on what has often been called ‘city gas’ – a mix of carbon monoxide and hydrogen. In the UK, it was

discovered in the late 18th Century that gas manufactured from coal could be used for lighting, and soon after gas lit lamps illuminated London’s streets. In the US, Baltimore was the fi rst city with gas lighting, with the fi rst street lamp in 1817.

In the beginning, gas was primarily used as a fuel for lamps before the invention of the Bunsen burner in 1855 opened up new opportunities by allowing for controlled burning of gas to be used as a source for heating and cooking.

The production of gas grew as the manufacturing of coke became vital for the emerging steel industry. Eventually, most of the world developed gas works in order to deliver gas specifi cally for the household and commercial sector. Such networks grew, and thereby became large interconnected pipeline grids. This gas grid would later be the foundation for distribution of natural gas.

Figure 1. Connect LNG’s UTS® is a fl oating system that replaces a jetty or quay and transfers LNG between the LNG carrier and onshore terminals.

70Summer 2018

Natural gas infrastructure developsIn the early days of oil production, associated gas was seen as a nuisance byproduct of oil production and eliminated as cheaply as possible through methods such as venting or fl aring.

The modern age of natural gas began with the discovery of the giant Groningen fi eld in the Netherlands in 1959, brought into production in 1963 with exports to Germany, Belgium and France. Transmission pipelines were built and natural gas was introduced and mixed with the city gas.

This put North-Western Europe on the map as a petroleum district, leading to rapid developments of oil and gas fi elds across the region. These discoveries coincided with the fi rst and second oil crisis, when oil prices skyrocketed due to export embargoes and cartel practices. Europe feared for the security of energy supply, turning to natural gas as an alternative to oil. In addition, US President Ronald Reagan was hesitant to let Europe become too dependent on Soviet gas, pushing both the buyers and sellers of Norwegian gas to reach delivery agreements from the giant Norwegian gas fi eld Troll to North-Western European buyers. As a result, the market for natural gas in Europe grew rapidly.1

LNG catalyses a new era for natural gasTechnology for the liquefaction of natural gas on a commercial scale was developed during the fi rst decades of the 20th Century, which was a major breakthrough for the storage and transportation of natural gas in tanks.

The fi rst large LNG production facility was built in Arzew, Algeria, and the fi rst commercial cargo of LNG was delivered to the UK in 1964. The fi rst purpose-built LNG carrier, Methane Princess, embarked upon a fi ve-day journey to Canvey Island, where the LNG was regasifi ed and was offl oaded via pipelines to major cities in the UK.

Natural gas could now be transported between continents, which had previously been unfeasible. It could then be transported further on smaller LNG carriers, and fi nally on trucks with small LNG tanks.

Today, the LNG industry is growing at an unprecedented pace, and new exporters and importers are continuously joining the mix. Although it was expected that the new supply currently coming onstream would lead to oversupply of LNG, this does not seem to be the case and the pace of growth shows no signs of abating.

LNG: the solution for new markets, but bottlenecks remainHistory shows that the lack of technology and solutions for transporting natural gas effi ciently has always been a bottleneck for development of infrastructure to get the gas from source to consumer. The abundance of natural gas, combined with the fl exibility of transportation as compared to pipelines, makes LNG

the obvious solution for markets without an established gas grid that are considering switching to cleaner energy.

However, LNG terminal construction can be diffi cult due to the ‘not in my backyard’ (NIMBY) premise. It is hard to fi nd suitable locations for terminals as proximity to existing harbour structures with accompanying harbour activities and habitation areas is often important for keeping costs down. Without making use of existing facilities, the development of infrastructure with jetty and quay structures is time consuming, costly, and may pose diffi culties with local regulatory compliance. Dredging may be required in shallow areas, which adds to cost and construction lead time, while environmental concerns regarding potentially polluted seabeds also need to be addressed.

Efficient loading and unloading of LNG Connect LNG has developed the patented Universal Transfer System (UTS®) in collaboration with the Spanish multinational gas and electricity company, Gas Natural Fenosa. The system is the fi rst of its kind, based on state-of-the-art jettyless technology.

It is a fl oating solution, consisting of a small platform with fl oating fl exible hoses that remove the need for a quay or jetty. The system can be produced anywhere in the world, easily installed, and is fully mobile, should it be benefi cial to move the system from one location to another.

Enabling LNG transfer anywhereThe transfer system can be deployed anywhere, regardless of local conditions (e.g. shallow waters). For greenfi eld terminal projects, the solution can be located away from highly populated areas and protected environments, which pose diffi culties with permitting. For brownfi eld terminal projects, where harbour space is limited and other activities prevalent, the transfer solution can be fl exibly situated where deemed optimal for LNG loading and unloading.

On 7 October 2017, the world’s fi rst jettyless LNG loading system, the UTS, carried out its fi rst commercial operation in

Figure 2. Connect LNG delivers a mobile turnkey solution that enables distribution of cleaner energy to areas that were deemed economically unfeasible.

LNG Industry

For more news visit:www.lngindustry.com

Global coverage of the entire

LNG value chain

72Summer 2018

one of Norway’s busiest ports, at Herøya outside Porsgrunn. The system was installed in less than a day, proving the rapid deployment ability of the solution. Two days later, the system was safely connected to the SkanGas chartered LNG carrier Coral Energy. LNG was transferred from the ship manifolds

through the UTS to Skagerak Naturgass’ onshore tanks. When the operation was completed, the system was safely disconnected from the LNG carrier and guided back to its idle position near shore. The UTS is designed to comply with all applicable rules and regulations, and has undergone full class approval by DNV GL.

Enabling cleaner energyThere is an increased focus on natural gas due to its vast range of application areas, favourable price and increasing environmental concerns. Natural gas is the cleanest fossil fuel with the potential to have a global impact on greenhouse gas (GHG) emissions. Due to the fact that it is burned at lower temperatures, combustion of natural gas is relatively free of soot, carbon monoxide and nitrogen oxides.

However, transportation bottlenecks have hindered the development of natural gas availability in the past, and this issue still needs to be resolved in order to effi ciently enable access to natural gas worldwide.

It can be diffi cult for markets to switch their energy source from diesel or coal to natural gas due to a lack of infrastructure. Construction of long jetties in shallow areas are most often independent of terminal size and can make the business case unfeasible for any terminal size, let alone small to mid-scale terminals. Connect LNG’s UTS is a proven jettyless solution, enabling quick access to LNG in diffi cult to access locations. Connect LNG and Gas Natural Fenosa have brought to life a jettyless solution that enables quick access to LNG in diffi cult to access locations.

Reference1. HALMØ, T. M. et al, 'The Gas Value Chain', University of Stavanger, (2017).

Figure 3. The UTS in operation at Herøya in Norway, transferring LNG from the SkanGas chartered LNG carrier Coral Energy to Skagerak Naturgass’ onshore LNG terminal.

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