6.20-offshore-mechanical-equipment-selection-philosophy.pdf

KCP-GNS-MEC-DPR-0001 Rev.: 04

Project Title: Kingsnorth Carbon Capture & Storage Project Page 1 of 13

Document Title: Offshore Mechanical Equipment Selection Philosophy

Kingsnorth CCS Demonstration Project The information contained in this document (the Information) is provided in good faith. E.ON UK plc, its subcontractors, subsidiaries, affiliates, employees, advisers, and the Department of Energy and Climate Change (DECC) make no representation or warranty as to the accuracy, reliability or completeness of the Information and neither E.ON UK plc nor any of its subcontractors, subsidiaries, affiliates, employees, advisers or DECC shall have any liability whatsoever for any direct or indirect loss howsoever arising from the use of the Information by any party.

Offshore Mechanical Equipment Selection Philosophy

Table of Contents 1 SCOPE AND FUNCTIONAL REQUIREMENTS 1.1 SCOPE OF DOCUMENT 1.2 DEFINITIONS 1.3 ABBREVIATIONS 2 ASSUMPTIONS 3 DESIGN REQUIREMENTS 3.1 DESIGN OBJECTIVES 3.2 PACKAGED EQUIPMENT 3.3 PUMPS 3.4 ATMOSPHERIC TANKS 3.5 PRESSURE VESSELS 3.5.1 General 3.5.2 Non-metallic Internal Lining 3.5.3 External Coating 3.5.4 Vessel Supports 3.6 PIPING AND VALVES 3.6.1 General 3.6.2 Pressure Relief Systems 3.6.3 Flexible Piping 3.6.4 Threaded Construction 4 MANDATORY REFERENCES 4.1 UK STATUTORY INSTRUMENTS / CODES & STANDARDS 5 SUPPORTING REFERENCES 5.1 PROJECT DOCUMENTATION

Sch 7 ref.: 6.58 Approved for Knowledge Transfer

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1 SCOPE AND FUNCTIONAL REQUIREMENTS

1.1 Scope of Document This document has been produced to outline the philosophy for the mechanical equipment selection for the offshore facility at the Hewett gas reservoir. This mechanical equipment selection philosophy is proposed in order to ensure that appropriate mechanical (rotating and static) equipment is selected for the offshore facilities of the Kingsnorth Carbon Capture & Storage Project. Therefore, it should be noted that this philosophy will be used derive specifications and datasheets for each item of mechanical equipment.

1.2 Definitions

1.3 Abbreviations ANSI American National Standards Institute ASME American Society of Mechanical Engineers ATEX Atmosphere Explosive API American Petroleum Institute BEP Best Efficiency Point BS British Standards CAPEX Capital Expenditure CE Conformit Europene CO2 Carbon Dioxide DCS Distributed Control System FEED Front End Engineering Design HP High Pressure IP Ingress Protection JT Joule-Thompson LAT Lowest Astronomical Tide LO Locked Open LC Locked Closed LP Low Pressure NPSH Net Positive Suction Head NPT National Pipe Thread OD Outside Diameter PFD Process Flow Diagram PPM Parts per million PSV Pressure Safety Valve P &I D Piping and Instrumentation Diagram TSA Thermally Sprayed Alloys





2 ASSUMPTIONS The CO2 from the Kingsnorth Power Station is intended to be captured in the depleted Hewett reservoir. It has been assumed that this selection philosophy shall apply to mechanical equipment contained at the offshore topsides only. It has been assumed that the design life for these facilities is 40 years. It is assumed that an Instrument Air System shall not be provided on the offshore facility. It is also assumed that CO2 shall not be used as a motive medium due to low temperatures and solids forming when venting. Hydraulic power is to be the preferred motive medium for valve operation.

3 DESIGN REQUIREMENTS

3.1 Design Objectives Although the design life for the project options is 40 years, it may be difficult for equipment vendors to ensure support for all their components for this duration. Therefore the onus is on the supplier to identify all consumables and limited life components on the spare parts listings, so that mitigation measures can be considered at the design stage. Materials of construction selected for any mechanical component shall be suitable for the design conditions stated in the Basis of Design for Studies [S1]. The mechanical equipment in direct contact with the transported fluid shall be designed for the stated CO2 properties, whilst all mechanical equipment exposed to atmospheric conditions shall be designed for the stated environmental conditions (i.e. ambient temperature). The water content of CO2 must be limited by the need to avoid the formation of solid hydrates or a corrosive, free-water phase during the injection process. Further guidance is provided in the Material Selection and Integrity Protection Report [S4]. Most natural gas developments will identify the major accident events to arise from the hydrocarbon processing activities. The inert nature of CO2 makes it a non-contributory factor to a major fire event. Whilst carbon dioxide is itself inert, the processing of it presents risks of its own. These include asphyxiation, pressure hazard and hazard from the contaminants present in the stream. Great attention must therefore be paid to the concept safety aspects (such as plant location and proximity to people, volumes of fluid, uncontained release events). As engineering develops there is also much in the engineering detailing, such as in the gas detection and warning, system isolation philosophies, etc. The operating philosophy must go hand-in-hand with the design to prescribe where, for example, breathing apparatus will be





required, and where other risks must be managed such as confined space access or pressure source isolation. A further feature of carbon dioxide, common to natural gas, is Joule-Thomson (JT) cooling on reduction of pressure. In the case of carbon dioxide, very low temperatures may be produced at pressure let-down points, requiring careful engineering and detailing of metallurgy. Cold thermal creep upstream of the pressure let-down point is one example. Therefore, a staged blow-down strategy should be considered. Venting CO2 to atmosphere can produce hazardous solid deposits (dry ice) due to the JT effect. Since dry ice is capable of burning human skin, vent discharges should be carefully located away from normally manned areas. In addition, careful design should ensure the number of bends in the outlet piping which could be subject to impact by solids is minimised. As far as possible, inherently safe design shall be used in order to avoid HP/LP interfaces.

All equipment shall be designed to permit rapid and economical maintenance. Major parts, such as casing components and bearing housing shall be designed (shouldered and/or dowelled) to ensure accurate alignment on reassembly. Shaft seals and bearings shall be accessible for inspection and replacement with the minimum of disassembly. Oil reservoirs and housing which enclose moving lubricated parts; such as bearings, shaft seals, highly polished parts, instrument and control elements, shall be designed to minimise the entrance of moisture, dust and other foreign matter during periods of operation and idleness. The maintainability of equipment must be considered at the equipment selection stage. This shall include:

Documentation comprising instruction, operation and maintenance manuals, drawings with full parts listing, a full list of spare parts relating to the drawings supplied.

Special tooling where applicable. Any special drawings or instruction regarding the use of such tools shall be included in the instruction, operation and maintenance manual. These tools shall be available before commissioning starts. These shall include any special lifting facilities, which may be required (e.g. a certified lifting frame or beam(s), including slings and shackles).





Lists of the following spare parts with current pricing and delivery shall be made available at the procurement stage for;

commissioning spares;

list of recommended spares for two years, five years and forty years operation.

3.2 Packaged Equipment Packaged equipment shall be used wherever possible instead of custom designs. This shall facilitate a modular construction approach and standardisation. Reliability of all offshore facilities equipment, including the packaged units, shall meet project requirements and support the overall availability/operation efficiency targets. Generally, equipment items shall be selected from Vendor's standard ranges. Prototype equipment shall not be considered. Only equipment which is of a similar size, type, rating and method of manufacture with which the Vendor can demonstrate satisfactory experience shall be supplied. A potential Vendor shall provide with his proposal details of such equipment packages in service. A review of critical systems shall be performed in FEED to ensure this target is met. Details of all items which are not of the Vendor's own manufacture shall be disclosed to the Contractor. Similarly any intent to employ Sub-contractors to partly or wholly manufacture, assemble or fabricate any part of the packaged unit shall be disclosed to the Contractor. All packaged equipment shall comply with the ATEX Directive 94/9/EC, Pressure Equipment Directive (97/23/EC) and the CE Marking Directive. The CE marking shall be indicative that the product meets the essential requirements of all relevant European Directives. Packaged equipment shall include earthing connections to allow isolation. Provisions for fire and gas detection and protection for packaged equipment shall be provided. Packaged equipment shall be fully instrumented with the Vendors standard instrumentation in order to mitigate the need for custom specifications. The Vendor shall supply the packaged equipment complete with tappings and the instruments that are an integral part of the proprietary equipment. Instrumentation shall be supplied to the Vendor's standards, except that each instrument shall be given a tag number following the Contractor's tagging system. The Vendor's scope of supply includes the functional specification, special tools, special test equipment, drawings and documents which shall include the factory acceptance test procedures.





The scope of package instrumentation shall also address remote operation requirements for this normally unmanned installation. The Contractor shall be responsible for defining the interfacing requirements of the equipment with the DCS. The Contractor shall specify the amount and type of data that shall be transmitted to the DCS, together with the required faceplates, graphics, trends, etc., which shall be made available on the DCS operator interface. The equipment package Vendor shall configure their system for transmitting the specified amount and type of data and work out with the DCS Vendor how the data shall be received, together with the required presentation format at the operator interface. Packaged equipment shall be designed to include all necessary stairs, ladders, platforms to access all PSVs and instrumentation. However, ladders shall be minimised in favour of stair access, especially where frequent or prolonged access is required. All skids / units shall be protected in an enclosed environment capable of being sealed from the ingress of dust, moisture, weld splatter and other damaging objects. The covering shall be of a non-flammable material and sufficiently strong to prevent penetration of falling objects. Units shall also be protected from dropped objects by the use of lightweight scaffolding boards or similar, each closely butted to the next, which shall be securely fastened to the supporting frame. The top of the packaging to be provided with the ability to shed rainwater. The skid should be positioned such that the skid shall not be damaged by localised flooding.

Exotic piping systems, including stainless steel, duplex, 6 Mo and CuNi, shall be protected externally from construction activities (i.e. shot blasting, fireproofing, painting and weld splatter). 3.3 Pumps The Vendor shall be responsible for the complete pump packages. For example, the scope of the sea water lift pump shown on Utility Flow Diagram Sea Water System [S2] shall include but not be limited to the following equipment:

pump unit (bowl assembly);

rising main (with line-shaft);

anti-marine fouling system;

overhead tank with hoses (if specified);

electric motor driver;

piping, valves and ancillaries;

base-frame;





pump controller (if required). The sea water lift pump unit shall be a vertically mounted, radial split, multi-stage assembly of mixed flow impellers. The Vendor shall estimate losses in the riser pipe in order to determine the total differential head required whilst assuming the pumped fluid is at the minimum operating level (Lowest Astronomical Tide LAT) and allowing for wave motion and the potential draw-down within the caisson. An allowance shall also be made for the pressure drop around the anti-fouling device and through the suction strainer, assuming that the free area of the strainer has been reduced by 50 % by fouling. The bowl as well as the impeller shall be single-piece castings with solid hubs. The bowl assembly and line shafts shall be sized to transmit the maximum torque required under any specified operating conditions as well as withstand all continuous stresses resulting from supported weights, thrusts and starting. The pumps shall be provided with eyebolts or lugs to facilitate lifting. Each type of pump packages shall be designed for continuous operation at design conditions or intermittent duty at specified conditions. This requirement will determine the quality of the pump package design. It should be possible to separate and remove the electric-motor or the pump unit for inspection and maintenance. The head/capacity curve shall be stable and rising continuously to shut-off. The shut-off head shall be between 110% and 140% of the head at the rated capacity. It shall be possible to increase the head by 5% at rated conditions by installing a new impeller or impellers. The best efficiency point (BEP) shall be close to the normal operating point and within 80% to 115% of the rated flow. Pumps shall have a non-overloading power/capacity characteristic unless otherwise approved by the Contractor. The Vendor shall specify the minimum Net Positive Suction Head (NPSH) when the pump is operated on water at the rated capacity and rated speed. Electric motor and terminal boxes shall be waterproof. The ingress protection of the motor shall be at least IP 55 and the ingress protection of the terminal boxes shall be at least IP 65, in accordance with IEC 60529. The motor shall be supplied complete with one-piece power cable. The cable shall terminate at deck level in a flameproof junction box to IP56 suitable for mounting directly on the deck, with a support structure high enough to allow for the minimum bending radius of the incoming feeders into the bottom of the box. The junction box and support structure shall be supplied by the Vendor and shall be coated with a paint system suitable for an open marine environment.





3.4 Atmospheric Tanks The atmospheric tank shall be complete with a stand suitable for mounting directly on the deck. Unless otherwise agreed each tank shall be complete with at least the following:

local gooseneck vent;

valve operated level gauge;

man-way / inspection opening;

level switch for low tank level alarm;

filling connection;

flanged connections for chemical dosing. The overhead tank shall be provided with an earthing boss consisting of a bar welded directly to the tank. The face of the boss shall be machined square. The thread and machined face shall be left unpainted.

3.5 Pressure Vessels

3.5.1 General

Pressure Vessels (i.e. Electric Heaters E-0001A and E-0001D shown on P.F.D Offshore & Transport System CO2 Process System Demo Phase (Base Case) [S3]) are to be designed to one of the following National and International Standards and Codes. Pig receivers shall also be designed to one of the following pressure vessel codes and not to pipeline codes as standard. Latest editions of all referenced documents shall apply.

Pressure Vessels ASME VIII Div 1 & 2

Unfired Fusion Welded Pressure Vessels PD 5500

Unfired Pressure Vessels EN13445

For flanges and bolts, the design temperature shall be as in the following table:

Mechanical Items % of vessel design temperature

Flanges: Un-insulated Insulated

Lap-joint flanges 85 100

Other type flanges 90 100

Bolts for Flanges 80 100

The Contractor shall specify on the data / requisition sheets whether a detailed fatigue analysis is required to be performed by the Vendor. If a detailed fatigue analysis is specified, the Contractor shall specify the required fatigue service lifetime and all operating data necessary for the Vendor to





perform the analysis. If a vessel is intended to be used in a service where more than one set of operating parameters (pressure and temperature) is envisaged, the data shall include this information and shall state the duration of each envisaged operating mode.

3.5.2 Non-metallic Internal Lining

Where vessel fabrication is carbon steel, internal corrosion protection may be provided by non-metallic lining. In such cases, where corrosion resistant attachments are used then protection against galvanic corrosion should be demonstrated. Quality control of coating application is crucial and it should be demonstrated how this shall be managed.

3.5.3 External Coating

The adequacy of coating selection and application should be ensured. Thermally Sprayed Alloys (TSA) is generally regarded as the most effective external corrosion protection but quality control of its application including sealing coats is crucial. A cold repair technique (for offshore use) should be confirmed as compatible with the selected TSA coating. Pressure vessels constructed from corrosion resistant alloys may not require external coating.

3.5.4 Vessel Supports

Legs may be used as supporting structures in proven applications. All vessel supports shall be provided with at least 2 earthing bosses. The baffles in separators can cause internal damage to linings if they become loose. Screw-based jack out systems anchored to the external shell can fail if the design does not allow for vessel movement. Baffle failure may be monitored by acoustic methods. Permanent monitoring at specific monitoring points is to be trialled on the existing design and may be a requirement for the new vessels.

All vertical vessels shall be provided with lifting trunnions, or lifting lugs as specified on the data / requisition sheets. Lifting lugs and trunnions shall be designed for a total load of 1.5 times the lifted weight of the equipment to allow for dynamic effects, etc., attached by full penetration welds.

3.6 Piping and Valves

3.6.1 General

All piping shall be installed and supported in such a way that items of equipment can be maintained or replaced with the minimum of disturbance





to the pipe work. All pipe work shall be installed within the base frame plan.

Piping terminations shall be grouped at the edge of the base-plate at locations to suit the Contractor's piping layout. Main process connections shall be the subject of negotiation between the Vendor and Contractor.

All terminations shall have flanges to ASME/ANSI B16.5 Pipe Flanges and Flanged Fittings.

Piping shall be in accordance with ASME B31.3 Chemical Plant and Petroleum Refinery Piping.

Piping shall be routed so that the shortest practical length and a minimum number of fittings and valves are used consistent with a safe, operable and maintainable layout without causing obstruction to access routes.

All equipment shall have provision for drainage. The minimum size of drain pipe work shall be 1 in. nominal bore.

Where a piping system is connected to another system or to equipment of a higher design rating, the higher rating shall prevail for all piping components up to and including the first block valve in the system of the lower rating.

Access for bolt torquing / tensioning equipment shall be provided.

3.6.2 Pressure Relief Systems

Unless specified otherwise, the selection, sizing and design of relief valves or rupture discs shall be in accordance with API RP 520 Part 1 Recommended Practice for the Design and Installation of Pressure-Relieving Systems in Refineries, API 521 Guide for Pressure Relief and Depressurising Systems and PD5500 Specification for unfired fusion welded pressure vessels.

Relief devices in gas or vapour service should normally be connected to either the vessel vapour space or the outlet piping.

If part of a system containing a liquid can be blocked in by valves and the internal pressure can rise above the maximum allowable working pressure of the piping system due to ambient influences, a thermal expansion relief valve shall be provided.





All relief valves shall be accessible from deck level or a permanent platform with safe and practical access provided via stair or ladder and a lifting plan for removal and reinstatement.

Piping for relief valves shall be arranged to avoid pockets.

The outlet line from a relief valve shall be self-draining.

Isolation valves shall only be installed before or after pressure relief valves when specifically required.

When pressure relief valves are fitted with isolation valves, these shall be indicated on P &I Ds and appropriately identified with either the symbol `LO' (Locked Open) or `LC' (Locked Closed).

Isolation valves shall be fitted where spare relief valves are installed, and their lock key release system shall be such that pressure relief protection is provided at all times.

Piping on the exhaust side of relief devices shall be designed or braced to ensure that exhaust reaction loads or moments do not exceed that specified by the relief valve Manufacturer.

3.6.3 Flexible Piping

Flexible piping shall not be used except with the Company approval.

Flexible hoses for high-pressure hydraulic applications shall be purchased in accordance with either BS 4586 or BS 3832, depending on application. Couplings shall be in steel with cadmium plating in accordance with BS 1706 Cd4 to a design to be approved by the Contractor.

Flexible hoses shall be supported by bolted clamps incorporating inserts of insulating material. The Vendor's attention is drawn to the minimum bend radii stipulated in Table 3 of either BS 4586 or BS 3832.

Flexible metallic hose assemblies shall be purchased in accordance with BS 6501 Parts 1 and 2 for corrugated and strip wound hose assemblies respectively.

Where the corrugated type is required for service in a vibrating environment then only Types B or C shall be used. Braiding shall be used when there is a requirement to withstand pressure greater than 3 barg or where vibration damping is required





Strip-wound hoses shall be of the double overlap type. If required to be leak proof they shall be of the packed double overlap (interlock) type.

Carbon steel end fittings shall not be used with stainless steel hose.

The Vendor's attention is drawn to the minimum bend radii stipulated in BS 6501 Parts 1 and 2, Table 3 Flexible metallic hose assemblies.

All flexible hoses used in process applications shall be externally braided with stainless steel.

Flexible rubber unarmoured hoses of the Vendor's standard for utilities at pressures no higher than 3 barg may be used for short lengths not greater than 10 diameters or 250mm, whichever is the greater, where there is no likelihood of external mechanical damage

3.6.4 Threaded Construction

Threaded connections shall only be used where specified in the Piping Classes. However, the Vendor may seek approval from the Contractor for their use where fully welded flanged construction cannot be used (e.g. space limitation). When approval is given, the following shall apply:

threaded pipe shall have a minimum wall thickness of Sch.80 for sizes up to DN 50 (2in NB), and Sch 40 for DN 80 (3in NB) and DN 100 (4in NB);

all threads shall be in accordance with ANSI B1.20.1 Pipe Threads General Purpose. They shall also be NPT tapered, and shall be clean cut and concentric with the OD of the pipe.

threads shall NOT be seal-welded;

where threaded flanges are necessary the pipe shall terminate 1.5mm short of the flange face.





4 MANDATORY REFERENCES

4.1 UK Statutory Instruments / Codes & Standards

[M1] SI 2005/3117 Offshore Installations (Safety Case) Regulations.

[M2] SI 1995/743 The Prevention of Fire and Explosion and Emergency Response Regulations (PFEER).

[M3] SI 1996/913 Offshore Installations and Wells (Design

and Construction, etc) Regulations (DCR).

[M4] 94/9/EC ATEX Directive.

[M5] 97/23/EC Pressure Equipment Directive.

[M6] 93 68 EEC CE Marking Directive.

5 SUPPORTING REFERENCES

5.1 Project Documentation

[S1] Kingsnorth Basis Of Design For Studies KCP-GNS-PCD-STU-0001.

[S2] Utility Flow Diagram Sea Water System - KCP-GNS-PCD-

PFD-0001.

[S3] P.F.D Offshore & Transport System CO2 Process System Demo Phase (Base Case) KCP-GNS-PCD-PFD-0003.

[S4] Material Selection and Integrity Protection Report - KCP-GNS-

PLD-REP-0009.

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