NORSOK L-004

This NORSOK standard is developed with broad petroleum industry participation by interested parties in the Norwegian petroleum industry and is owned by the Norwegian petroleum industry represented by The Norwegian Oil Industry Association (OLF) and The Federation of Norwegian Industry. Please note that whilst every effort has been made to ensure the accuracy of this NORSOK standard, neither OLF nor The Federation of Norwegian Industry or any of their members will assume liability for any use thereof. Standards Norway is responsible for the administration and publication of this NORSOK standard.

Standards Norway Telephone: + 47 67 83 86 00 Strandveien 18, P.O. Box 242 Fax: + 47 67 83 86 01 N-1326 Lysaker Email: [email protected] NORWAY Website: www.standard.no/petroleum

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NORSOK STANDARD L-004 Edition 2, September 2010

Piping fabrication, installation, flushing and testing

NORSOK standard L-004 Edition 2, September 2010

NORSOK standard of 30

Foreword 5

1 Scope 6

2 Normative and informative references 6 2.1 Normative references 6 2.2 Informative references 6

3 Terms, definitions and abbreviations 6 3.1 Terms and definitions 7 3.2 Abbreviations 7

4 Materials 7 4.1 Colour marking of materials 7 4.2 Material storage, handling, recieval and identification control 7

5 Fabrication of pipework 8 5.1 General requirements 8 5.2 Welding and NDE 8 5.3 Butt welds for orifice runs 8 5.4 Screwed pipework 8 5.5 Dimensional tolerances for pre-fabricated piping assemblies 8 5.6 Branch connections and outlets 10 5.7 Pipe flanges, mechanical hub and clamp coupling 11

6 Installation of piping 11 6.1 Pipework erection 11 6.2 Flanged joints 11 6.3 Strain sensitive equipment with flange connections 12 6.4 Gaskets 12 6.5 Bolting 12 6.6 Pipe support 13 6.7 Global tolerances, installation 13

7 Cleaning of pipework 14 7.1 General 14 7.2 Hydro flushing 14 7.3 Pressurised air shockblowing 14 7.4 Pneumatic flushing 15 7.5 Soft pigging 15 7.6 Verification of cleanness 15

8 Pressure tests 15 8.1 General 15 8.2 Test preparation 15 8.3 Test media 16 8.4 Hydrostatic testing 17 8.5 Pneumatic testing 17 8.6 After completion of test 17 8.7 Test acceptance criteria 17 8.8 Test documentation 17

9 Chemical cleaning 18 9.1 General 18 9.2 Documentation 18

10 Hot oil flushing 19 10.1 General 19 10.2 Marking 19 10.3 Documentation 19

11 Tightness testing 20

12 System colour coding of piping 20 12.1 Purpose 20 12.2 Types of markers 20 12.3 Insulated lines 21



12.4 Plastic/rubber lined piping 21 12.5 Obstruction 21 12.6 Materials of markers 21 12.7 Fastening materials 22 12.8 Marker text 22 12.9 Size and use of markers 22 12.10 Positioning of markers 23 12.11 Valve marking 23 12.12 Fluid description/colour code tabulation 23 12.13 Colour coding information 23

Annex A (normative) Alternative test methods 24

Annex B (informative) Requirements for internal treatment of piping after prefabrication and installation before commissioning 26



Foreword

The NORSOK standards are developed by the Norwegian petroleum industry to ensure adequate safety, value adding and cost effectiveness for petroleum industry developments and operations. Furthermore, NORSOK standards are, as far as possible, intended to replace oil company specifications and serve as references in the authorities’ regulations. The NORSOK standards are normally based on recognised international standards, adding the provisions deemed necessary to fill the broad needs of the Norwegian petroleum industry. Where relevant, NORSOK standards will be used to provide the Norwegian industry input to the international standardisation process. Subject to development and publication of international standards, the relevant NORSOK standard will be withdrawn. The NORSOK standards are developed according to the consensus principle generally applicable for most standards work and according to established procedures defined in NORSOK A-001. The NORSOK standards are prepared and published with support by The Norwegian Oil Industry Association (OLF), The Federation of Norwegian Industry, Norwegian Shipowners’ Association and The Petroleum Safety Authority Norway. NORSOK standards are administered and published by Standards Norway.



1 Scope

This NORSOK standard covers the basis for fabrication, installation, flushing, pressure testing, chemical cleaning, hot oil flushing and system colour coding of process, drilling and utility piping for offshore oil and/or gas production facilities. This NORSOK standard does not cover the following: • all instrument control piping downstream of first piping block valve; • subsea pipework and risers; • flexible hoses; • sanitary piping systems within living quarters and other domestic areas, see NORSOK H-003; • GRP piping; • marine systems in hulls of vessels and floating platforms and land based plants.

2 Normative and informative references

The following standards include provisions and guidelines which, through reference in this text, constitute provisions and guidelines of this NORSOK standard. Latest issue of the references shall be used unless otherwise agreed. Other recognized standards may be used provided it can be shown that they meet the requirements of the referenced standards.

2.1 Normative references

ASME B31.3, Process Piping ASME B1.20.1, Pipe Threads, General purpose, Inch ASME PCC2, Repair of Pressure Equipment and Piping ASME VIII, Boiler and Pressure Vessel Code, Section VIII – Rules for construction of Pressure Vessels, Division 1 API 6A, API standard 6A NORSOK L-001, Piping and Valves NORSOK L-002, Piping design, layout and stress analysis NORSOK L-CR-003, Piping details NORSOK L-005, Compact flanged connections NORSOK M-601, Welding and inspection of piping NORSOK M-630, Material data sheets and element data sheets for piping NORSOK Z-DP-002, Coding system NORSOK Z-006, Preservation NS 813, Piping systems – Identification colours for the content NS 4054, Colours for identification ISO 4406, Hydraulic fluid power – Fluids – Method for coding the level of contamination by solid particles ISO 9095, Steel tubes – Continuous character marking and colour coding for material identification

2.2 Informative references

ASME PCC-1, Guidelines for Pressure Boundary Bolted Flange Joint Assembly EN 1591, Flanges and their joints ISO 19900, Petroleum and natural gas industries – General requirements for offshore structures OLF guideline 118, Håndbok for flensarbeid NORSOK H-003, Heating, ventilation and air conditioning (HVAC) and sanitary systems NORSOK N-001, Integrity of offshore structures

3 Terms, definitions and abbreviations

For the purposes of this NORSOK standard, the following terms, definitions and abbreviations apply.



3.1 Terms and definitions

3.1.1 shall verbal form used to indicate requirements strictly to be followed in order to conform to this NORSOK standard and from which no deviation is permitted, unless accepted by all involved parties 3.1.2 should verbal form used to indicate that among several possibilities one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required 3.1.3 may verbal form used to indicate a course of action permissible within the limits of this NORSOK standard 3.1.4 can verbal form used for statements of possibility and capability, whether material, physical or casual

3.2 Abbreviations

ABS absolute API American Petroleum Institute ASME American Society of Mechanical Engineers EN European Standard GRP glass fiber reinforced plastic He helium HVAC heating, ventilation and air conditioning ISO International Organisation for Standardisation IX special metallic seal ring, see NORSOK L-005, clause 5 N2 nitrogen N2He nitrogen helium NCR non conformance request NDE non destructive examination NPT National Pipe Thread Taper NS Norwegian Standard O2 oxygen OD outside diameter P&ID piping and instrument diagram PAS pressurised air shock blowing PVC polyester vinyl chloride UV ultra violet

4 Materials

4.1 Colour marking of materials

Colour marking shall be according to ISO 9095. If possible, gaskets shall be marked to be visible after installation.

4.2 Material storage, handling, recieval and identification control

Procedures for off-loading, storage, recieval, control, traceability and inspection of piping material supplied for fabrication and installation shall be worked out. In general, the following applies: • storage and preservation shall adhere to requirements in NORSOK Z-006; • storage of piping and piping equipment shall be under cover and protected against contact with the

ground;



• carbon steel and stainless steel components shall be segregated to avoid any cross contamination. • all fittings and equipment shall be protected against damage during handling from supplier to fabrication

yard and further to final installation plant. Especially focus shall be made to sealing surfaces, bevelled areas, and contact between different material qualities to avoid surface contamination. This also includes protection during erection phase in order to protect against contamination from other activities on site.

5 Fabrication of pipework

5.1 General requirements

Prefabricated pipe spools shall be cleaned, painted (if required) and preserved prior to installation. Internal cleaning of pipe spools shall be done by hydro flushing or hydro jetting. The fabrication yard shall be outfitted for work with relevant materials. Intermediate storing, lifting devices and handling equipment shall have a surface not causing contamination of the materials they are used for. All tools shall be restricted to the relevant material group to avoid rust contamination and shall be marked to avoid mixing of tools for different materials. Different grades of stainless steel materials can be handled with the same tools. Separate tools shall be used for titanium materials. All welded attachments to piping, including pads and doubler plates, shall be of a material 100 % compatible with the piping material. Fabrication of high alloy piping shall take place in areas separated from areas where carbon steel piping is fabricated. Titanium fabrication shall also be separated from stainless steel and carbon steel fabrication areas. Bending and forming of pipe shall be carried out in accordance with ASME B31.3, NORSOK M-630 (EDS NBE1 and EDS NBE2) and shall be carried out according to documented procedures.

5.2 Welding and NDE

All welding and NDE shall be in accordance with NORSOK M-601. Internals of in-line valves and equipment that could be damaged due to heat transfer shall be removed prior to welding and/or heat treatment.

5.3 Butt welds for orifice runs

When the design of an orifice run necessitates welds, these shall be ground smooth and flush with the inside of the pipe. Pipe-tap connections, where required, shall be drilled through the pipe wall and be smooth inside.

5.4 Screwed pipework

Unless otherwise stated on approved drawing or specifications, pipe threads shall conform to ASME B1.20.1. All threading shall be carried-out after bending, forging or heat treatment, but where this is not possible, suitable thread protection shall be provided. NPT threads need special attention to dimensional tolerances due to the conic configuration. Minimum engagement shall be 4.5 for NPT threads.

Tape shall not be used on threads for screwed piping connections.

5.5 Dimensional tolerances for pre-fabricated piping assemblies

Dimensional control of prefabricated piping spools shall be performed in a systematic manner, assuring that the final installation will be correct. Prefabricated spools for offshore installation shall be 100 % dimensionally controlled. The tolerances on linear dimensions (intermediate or overall) are illustrated in Figure 1 and Figure 2. These tolerances are not accumulative.



Angularity tolerances across the face of flanges, weld end preparation and rotation of flanges shall be as stated in Figure 1 and Figure 2. Closer tolerances on weld end preparations than stated in Figure 1 and Figure 2, may be specified in the relevant welding specification for the material in question, and shown on the fabrication isometric(s). When closer tolerances other than those given above are required, these shall be as specified on the isometric drawing in question.

L

L

L

L

3 mm per 1 m

Max 6 mm

T

L

L

L

L

L [m] ∆∆∆∆ L T

Tolerances [mm]

≤ 6 ± 5 ± 1,5 > 6 ± 10 ± 1,5

Figure 1 ― Tolerances for prefabricated piping assemblies



L

L

A

T

L2d L1

L2

d L1

K

T

H

L [m] L A T 2 in ≤≤≤≤ d ≤≤≤≤ 10 in

12 in ≤≤≤≤ d ≤≤≤≤ 20 in

d >20 in

Tolerances [mm] Tolerances [mm]

≤ 6 ± 3 ± 1,5 ± 1,5 L1 ± 3 ± 5 ± 5 > 6 ± 5 ± 1,5 ± 1,5 L2 ± 3 ± 5 ± 5

H ± 3 ± 3 ± 3 T ± 1,5 ± 1,5 ± 1,5

d = nominal diameter K ± 2 ± 3 ± 3

1.5 mm

X" X"

NOTE 1 Before reworking any spools contact engineering department in order to check complete isometric. NOTE 2 Cut to fit requirement to be stated on fabrication isometrics (typically 100 mm). NOTE 3 Bolt holes on flanges shall straddle the horizontal or vertical lines or plant north/south centre lines when orientation is

not given on drawings.

Figure 2 ― Tolerances for prefabricated piping assemblies

5.6 Branch connections and outlets

All welded branch connections shall be jointed to the header with full penetration welds. Stub-in connections shall be set-on type. Set-in type is not acceptable.



Reinforcement pads or saddles required by specifications and drawings shall be of the same material as the main pipe (unless specified otherwise) and shall be formed and countered to provide a good fit to both main and branch pipe. Branch reinforcement pads shall be according to ASME B31.3. Branch reinforcement pads or each segment thereof shall be provided with a minimum 3,0 mm drilled and tapped hole prior to fitting to the pipe, to ensure leak detection, venting and testing facilities. Whenever possible, pad should be made in one piece before fitting onto pipe. After welding and testing the hole shall be permanently plugged, e.g. welded or metal plug in piping material.

5.7 Pipe flanges, mechanical hub and clamp coupling

Seal faces of mechanical hub and clamp couplings and flanges shall be protected during fabrication and storage. Where possible, hub and clamp couplings shall be protected by fitting and hand tightening the complete coupling assembly. Particular attention shall be paid to protection of compact flange seal faces where reference is made to requirements in NORSOK L-005.

6 Installation of piping

6.1 Pipework erection

All pipes shall be inspected before erection to ensure that they are free from loose contamination. Pipework shall be erected on permanent supports designated for the line. Temporary supports shall be kept to an absolute minimum, but to an extent sufficient to protect nozzles and adjacent piping from excessive loads during the erection. Tubing shall not be used inside walls or other enclosed compartments without access. The weldolets shall be fully welded to the extent needed to confirm with the design requirements in ASME B31.3, and NORSOK L-001. Pipework shall be fitted in place without springing or forcing to avoid undue stressing of the line or strain being placed on a vessel or item of equipment, etc. All temporary pipe spools and supports that are an aid to erection, testing/flushing, sea fastening, etc. are to be specially marked for removal identification.

All valves shall be protected against ingress of dirt during any temporary storage.

6.2 Flanged joints

Before assembly, flanges shall not have any damage that will interfere with the integrity of the joint. The flanges shall be clean and free from any rust, dirt or other contamination. The joints shall be brought up flush and square without forcing so that the entire mating surfaces bear uniformly on the gasket and then mated-up with uniform bolt tension. With the piping flange fitted and prior to bolting-up the joint, the following shall be maintained: • bolting shall move freely through accompanying bolt-holes at right angle to the flange faces; • there shall be a clear gap between two flange faces before gasket installation. There shall be sufficient

flexibility to install and replace gaskets. Compact flange heel are one of two sealing surfaces and are vulnerable to damage from corrosion and rough handling and need special attention. For handling, installation and assembly of compact flanges, see NORSOK L-005. For work on flanges, OLF guideline 118 gives a practical view on flange work.



6.3 Strain sensitive equipment with flange connections

Flange covers shall be retained on all flange connections to valve or equipment, until ready to connect the mating piping. All equipment shall be blanked, either by pressure test blanks, spades or blinds, to stop the ingress of internal pipe debris. Flanges connecting to strain sensitive mechanical equipment (e.g. pumps, compressors, turbines, etc.) shall be fitted-up in close parallel and lateral alignment prior to tightening the bolting. Unacceptable forces transferred on to the nozzles shall be prevented. To achieve this true alignment, full advantage shall be taken of the 'cut to fit' allowances and loose flanges provided. In general, flange connections to strain sensitive equipment shall be the last connection made on completion of a line or interconnecting system of lines. With reference to NORSOK L-002, connections to strain sensitive equipment shall always be subject to stress analysis with true misalignment. As a minimum the following shall be evaluated:

• the stiffness of the system; • sufficient tightening force for flange connections; • allowable nozzle loads for the equipment. With the piping flange fitted and prior to bolting-up the joint, the tolerances shown in Figure 3 shall be maintained. Maximum angular misalignment:

Figure 3 ― Flange alignment for strain sensitive mechanical equipment In general, flange connections to equipment shall be the last connection made on completion of a line or interconnecting system of lines.

6.4 Gaskets

Gaskets (all types) shall be treated in accordance with manufacturers’ instructions. Gaskets shall not be re-used. Gaskets shall not under any circumstances, protrude into the bore of pipe. Ring type joints (RTJ) rings are to be lightly smeared on the mating surface with a propriety anti-friction lubricant prior to fitting between the flange grooves. Anti-friction lubricant, compatible with the flange material and process fluid shall be used. IX seal rings used in compact flange connections may be reused provided that the conditions in NORSOK L-005 are followed.

6.5 Bolting

Bolting shall be in accordance with NORSOK L-001, or the piping specification for the project.

B

A

D1

D

0.11

1000)(:"14

0.3mmB)(A:14"D4"

mm0.2B)(A:3"D

≤⋅−

≥

≤−<≤

≤−≤

D

BAD



Bolt tightening shall be calculated according to a recognized industry standard, e.g. ASME VIII, ASME PCC-1, API 6A and EN 1591. Manually torqued flange bolts and stud bolts shall extend fully through their nuts with minimum one and maximum five threads. To archive the required bolt tension lubrication is important, all flange bolts, stud bolts threads as well as nut spot faces shall be thoroughly lubricated prior to fitting. All flanged stud bolts shall be progressively controlled to equalise bolt pressure on the gasket. A detailed procedure shall be developed prior to start. All bolted flange connections shall have controlled tightening by means of manual torque wrenches or hydraulic bolt tightening. Hydraulic bolt tightening (tension or torque) shall be used on all bolts greater than 25,4 mm (1 in) diameter. If required the bolts shall have extra overlength of 1 x bolt diameter in order to accommodate tensioning tool. The Contractor is responsible to have a traceable system to document all bolted flange connections tightening by means of manual torque wrenches or hydraulic tightening. The flange connections shall be marked on a suitable document, e.g. a mark-up isometric drawing, “kontroll og aktivitetsskjema” in OLF guideline 118, or by using an electronically tracking system for flange tightening. Information shall include, but not be limited to the following information: • piping class; • tension/torque; • nominal flange size, pressure class, bolt size and length; • type of tool and hydraulic pump pressure; • date and signature by the operator. Nuts and bolts shall have their grade marks visible after installation. Stud bolts cut from long lengths of studding shall have material grade stamped on the end of each cut. For bolts larger than 25,4 mm (1 in) protection against mechanical damage and corrosion shall be evaluated, e.g. thread/nut protection caps.

6.6 Pipe support

Pipe supports shall be in accordance with the valid pipe support detail drawings developed for the project. For lines subject for comprehensive stress analysis (see NORSOK L-002), contractor shall ensure that the stress isometric drawings fully comply with the installed system with regard to pipe routing, pipe support locations and support functionality. Piping shall not be forced to fit with support locations in such a manner that additional stress is introduced. Where spring supports are installed, the spring shall be in fixed position with preinstalled load until mechanical complete is achieved. Pipes shall not be supported by other pipes, i.e. individual supporting is required. Bracing is, however, allowed according to NORSOK L-CR-003. Vent holes in wear plates and trunnions is not required. However, when the wear plate or a trunnion covers a circumferential weld that has not been pressure tested, a vent hole is required for leak detection.

6.7 Global tolerances, installation

Hook-up termination points shall be within ±25 mm in all directions. Overlength may be provided, where required. Installation tolerances of piping components shall be as required by the individual service of the piping component including requirements for



• maintenance access, • position relative to surrounding steelwork, equipment, cable tray and heating, ventilation and air-

conditioning (HVAC) duct routings, • positioning of pipe supports relative to the structural steel, • pipe stress.

7 Cleaning of pipework

7.1 General

The initial flushing shall be carried out prior to pressure testing. For austenitic steelwork flushing can be performed after pressure testing, upon agreement. General requirements for flushing for specific systems are listed in Table B.1. All pipework shall be free from all foreign materials (e.g. as dirt, grease, oxide scale, weld deposits and temporary protective coating) which could cause operational disturbances for the relevant service class. All flushing shall be performed according to a documented procedure. Cleaning shall be documented by visually inspection (including video, boroscope etc) of critical parts of the system, as agreed with Company. All items that can be damaged during cleaning shall be removed or blocked prior to cleaning, e.g. pressure gauges, flow meters, signal sensors, relief valves, permanent strainers, check/globe/control valves having reduced cross sectional areas, rupture discs, instrument probes, thermo wells, connection to vessels/pumps level instruments, etc. All orifice plates shall be installed after flushing and pressure testing.

7.2 Hydro flushing

Items of equipment which would be sensitive to damage during hydro flushing shall be removed, blocked off or isolated. A list shall be prepared and be part of the flush and test procedure. Ball valves shall be flushed in fully open position. Flanged ball valves shall not be installed until flushing is completed. Flanged ball valves may be installed when flushing is completed and prior to pressure testing, provided the fabrication contractor has verified acceptable cleanness of the system. For flanged riser- and pipeline valves, the valves shall not be installed before flushing, pressure testing and all clean-up pigging operations of the pipelines are completed. Welded ball valves shall only have the valve body installed during flushing and pressure testing. The valve internals shall not be installed until the flushing and pressure testing activities are completed. For welded in riser valves shall the pigging sleeves be used during all pressure testing activities and clean-up pigging operations of the pipelines. Valve internals shall be installed when all pipeline and riser activities are completed. All piping systems shall be flushed using high pressure jetflushing equipment, e.g. rotating hose or rotating nozzle. Minimum pressure shall be 60 MPa, and in the range 100 litres to 150 litres per min. The connection points shall be located such that all parts of the system are properly flushed. The piping system shall be hydro flushed to ensure that weld deposits are removed. The flushing medium shall be fresh water, the chloride ion content shall be less than 50 x 10

-6 (50 ppm), the

Ph value shall be between 6,5 and 7,5. After flushing shall the piping systems be completely drained and protected against corrosion.

7.3 Pressurised air shockblowing

This method may be used as an initial cleaning method for instrument air, plant air and as an alternative method for initial cleaning of small bore pipe (typical less than 50,8 mm (2 in)). This method may also be



used when there are problems removing trapped liquid in the circuit, or to verify cleanness of small bore pipe where video inspection is impossible or inadequate due to pipe dimension or configuration. When using PAS method for cleaning or verification the procedure shall be repeated until cleanness is acceptable. The air shocking pressure shall never exceed the working pressure of the system and shall never be more than 0,8 MPa. Safety precaution shall be taken when this method is used.

7.4 Pneumatic flushing

In cases where water is not desirable in the piping system (e.g. instrument/utility air), flushing by pressurised air or PAS shall be carried out. When pressurised air is used, the minimum velocity shall be 35 m/s. Procedure covering all safety aspects shall be established.

7.5 Soft pigging

Soft pig can be propelled using compressed air, vacuum, or water. Pressure shall not exceed design pressure of the system. When using compressed air, a procedure covering all safety aspects shall be established. A procedure developed for the operation shall describe in detail the arrangement for catching/receiving the pig in a safe manner. Items which can be sensitive to damage during soft pigging shall be removed. Inline valves except ball valves shall be removed. Ball valves shall be fully open. When using soft pigging for cleaning or verification the procedure shall be repeated until level of cleanness is acceptable.

7.6 Verification of cleanness

All systems shall be internal visual inspected for acceptable cleanness by spot check. Internal visual inspection includes the use of video or equivalent equipment. If pipe configuration in critical parts of systems as defined in Table B.1 is too complicated for visual inspection, the PAS method or other suitable methods shall be used for verification of cleanness.

8 Pressure tests

8.1 General

The test pressure shall, unless otherwise specified, be in accordance with ASME B31.3. The test pressure shall be calculated based on the maximum design pressure of the piping class (not the design pressure of the individual line) at 20 ºC. Special requirements for pressure testing of GRP plastic piping shall be clarified with the manufacturer. The following are excluded from pressure tests: • all small bore instrument control piping downstream of the first piping block valve; • open drains and vents to atmosphere (hydrostatic test with liquid fill). For alternative testing of tie-in welds, see annex A.

8.2 Test preparation

Pressure, temperature and time recorders shall be used for all pressure tests. The pressure shall be shown in barg. Pressure gauges and recorders used to indicate and record test pressure shall be dead weight tested for accuracy according to a procedure, dependent of type of equipment. Pressure and temperature gauges and recorders shall be calibrated in accordance with recognized calibration standards.



Minimum of one gauge shall be positioned at the highest point and one recorder to be positioned at the lowest point. Accuracy of pressure gauge shall be at least 1 % to 2 % at full scale and 1 % to 2 % for the recorder. The test pressure shall be within 60 % of the gauge range (20 % from top and 20 % from bottom). If there is a deviation of more than 2 % between gauge and recorder during test, the test shall be stopped and the equipment recalibrated. Piping joints, welds (including those used in the manufacturing of welded pipe and fitting, and structural attachment welds to pressure-containing components), and bonds shall not be insulated or physically covered until satisfactory completion of testing in accordance with this NORSOK standard, expect previously tested according to this NORSOK standard. All joints may be primed and painted prior to pressure testing. All piping shall be adequately supported before the pressure test. Spring or other variable type supports shall be blocked to prevent movement. Unless otherwise noted, all valves are to be through body tested. First block valve for pressure instruments shall be included in the test. If valves are included in the pressure test, the following applies: ball, plug, slab gate valves and other valves where the cavity pressure may differ from the bore pressure, shall be pressure tested in the half open position. All other valves shall be tested in the fully open position. When check valves are included in pressure test they shall be jacked open or have their internals removed. Where the test pressure to be applied to the piping is greater than the maximum allowable test pressure for valves, the valves shall be blinded off on the side to be tested, or removed and replaced by dummy spools. Turbines, pumps, compressors and vessels shall be blinded off prior to pressure testing. A list shall be prepared for sensitive equipment (i.e. expansion joints, relief valves, inline instruments, etc) that shall be removed, blocked off or isolated during testing. This list shall be a part of the test procedure.

8.3 Test media

For hydrostatic testing the test medium shall in general be fresh water, except that other suitable liquid may be used if • the piping or inline equipment would be adversely affected by water, • the liquid is flammable (it's flash point shall be at least 49 °C

and consideration shall be given to the

environment). The flushing medium shall be fresh water, the chloride ion content shall be less than 50 x 10

-6 (50 ppm), the

Ph value shall be between 6,5 and 7,5. The line shall be properly drained as soon as possible after testing. If ambient temperature falls below 2 °C some time during the entire testing period (until dried system), the test water shall have antifreeze added. Carbon steel systems as defined in Table B.1 shall be tested with an acceptable preservation fluid to prevent rust. For pneumatic testing, the test media shall be oil free, dry air or any inert gas. The use of air for testing shall be limited to a maximum pressure of 0,7 MPa overpressure. Above this pressure nitrogen shall be used. The extent of pneumatic testing shall be approved. All safety aspects using compressible test media shall be evaluated. For instrument/utility air systems, where the introduction of water is undesirable, test media shall be oil free dry air or any inert gas.



8.4 Hydrostatic testing

The test pressure shall be maintained for a sufficient length of time to permit visual examination to be made of all surfaces, welds and connections, but not less than 30 min. 1 h test duration shall apply for piping systems with pressure rating class 600 and above. Care shall be taken to ensure that overpressuring due to static head does not take place.

8.5 Pneumatic testing

The sequence of test pressuring installed systems shall be as follows: 1. A pressure of 0,05 MPa overpressure shall be introduced in the system and a leak test performed. The

pressure shall gradually be increased to 50 % of the specified test pressure and kept for minimum 10 min to equalize strain.

2. The pressure shall then be increased in steps of 10 % of the specified test pressure, until the specified test pressure is reached. At each step, the pressure shall be kept for minimum 10 min to equalize strain.

3. The specified test pressure shall be kept for 1 h. The pressure shall than be reduced to the design pressure before examining for leakage.

4. The piping systems shall not show any sign of plastic deformation or leakage.

8.6 After completion of test

The tested systems shall be depressurised by opening the depressurising valve in the test rig. After depressurisation, all vents and low point drain valves shall be opened and the system shall be thoroughly drained where the test medium is water. Where required, blowing by dry air or pressurised air shock blowing to remove any trapped water shall be performed to remove any residual or trapped water. Systems with drying requirement as defined in Table B.1 shall be dried out after hydro testing with dry oil free air with a dew point of -10 °C. Drying can be terminated when the dew point at the outlet is equal to the dew point at the inlet. Other methods (e.g. vacuum drying or air shocking) may also be used if the same dryness can be documented. Requirement for drying as defined in Table B.1 shall take in to consideration the time for start up of system. If more than 3 months to commissioning, drying shall be followed by preservation with nitrogen to keep the pipe system completely dry and to avoid condense. Other alternatives are subject to agreement. Reinstallation of the system shall be performed in accordance with the test procedure. After completion of flushing and pressure testing, the valve internals for welded in ball valves shall be installed by the valve supplier. Prior to installation, the ball valves shall be inspected for cleanness. All ball valves shall be pad-locked in open position. After the installation of the valve internals the valve shall be pressure tested through the body cavity drain port. Where permanent or temporary strainers have remained in place for the hydrostatic pressure test, they shall be removed following the test and thoroughly cleaned before reinstalling. Ends of pipes and nozzles shall be fully protected against the ingress of foreign material by the use of caps, plugs or plate blinds sealed with gaskets. These shall not be removed until just prior to final assembly. Flange parallellity and alignment to equipment shall be checked prior to reinstatement. All lines or joints that fail to pass the pressure test shall be re-tested to the same procedure after repairs.

8.7 Test acceptance criteria

The piping systems shall not show any sign of plastic deformation or leakage.

8.8 Test documentation

For all pressure tests, documentation shall be fully traceable during the commissioning period of the tested pipe. The documentation shall include, but not be limited to • a valid test certificate specifying date, location, line numbers, test pressure, test medium and test duration,



• a test record chart fully specifying the pressure, temperature and time relation during the test period.

9 Chemical cleaning

9.1 General

Lines to be chemical cleaned shall be identified on the P&IDs and Line Index. For system overview, see Table B.1. Acceptance criteria for chemical cleaning shall be according to ISO 4406. As a minimum the following piping systems shall be chemically cleaned: • lubrication oil; • seal oil/gas or other seal fluids; • fuel oil/gas (critical parts only); • relevant part of gas compressor suction lines; • process discharge to anti-surge control and safety relief valves; • hydraulic oil systems with requirement to cleanness. A procedure shall describe in detail the steps for chemical cleaning and shall include, but not be limited to • degassing, • chemical cleaning/descaling, • neutralization, • passivation, • water flushing, • drying. The end result shall be a clean smooth surface. Maximum temperatures used during these operations shall not exceed maximum design temperature for the systems as listed in the Line Index. For equipment such as turbines, generators, pumps and compressors, the piping to be cleaned shall have all sensitive items that can be damaged by the cleaning medium removed or blanked off. Generally, the following items shall not be chemically cleaned (items shall be identified on isometric drawings for chemical cleaning): • all instrument tubing downstream the first piping block valve; • piping systems with copper alloy materials; • flexible hoses; • vessels; • exchangers; • pumps; • all bolted/screwed valves and instruments. Removed or blanked off items shall be cleaned separately. The systems to be cleaned shall have high and low point vents and drains installed. "Dead legs" shall be avoided. To assure turbulent flow and proper transportation of particles, the flow requirements used for hot oil flushing (see Table B.1) shall apply. Cleaning shall be carried out after pressure testing unless otherwise specified. If more than 3 months to start up of commissioning activities the system shall be preserved with nitrogen. Overpressure shall be 0,05 MPa.

9.2 Documentation

The compliance to specified ISO 4406 requirements shall be documented by relevant laboratory analysis certificate. The level of cleanness shall be documented from an automatic particle counter or a membrane checked in a microscope, before the water flushing operation is considered finalised.



10 Hot oil flushing

10.1 General

All piping subject to hot oil flushing, shall in advance be chemically cleaned to the required cleanness level. Required cleanness for systems subject to hot oil flushing shall be in accordance with Table B.1. Acceptance criteria for hot oil flushing shall be the same as for chemical cleaning of the similar systems. A detailed procedure for hot oil flushing shall be written and approved by Company prior to start. Filters used for hot oil flushing shall be • ≤ 3 µm ABS for hydraulic systems, • ≤ 10 µm ABS for lube and seal oil. Filling of lubricant oil shall take place through filters with 10 µm ABS. Flushing and sampling to verify cleanness shall take place at turbulent flow, upstream any filters. The fluid samples shall be representative of the system with 2 to 3 test points. To assure turbulent flow and proper transportation of particles, the flow requirements given in Table 1 shall be met during flushing.

Table 1 ― Minimum velocity requirements

Pipe size inch

Reynolds number Minimum flow velocity m/s

1/2 to 1 > 4 000

1 1/4 to 4 1,25

6 0,5

The oil used for flushing shall be identical to the oil used in operation. The oil viscosity shall be lower than or equal to the viscosity of the oil used in operation. Flushing oil shall, if possible, remain in the system after completion of flushing. Preservation shall be performed, either by N2 overpressure, chemical additive or other suitable method. The level of cleanness shall be documented from an automatic particle counter or a membrane checked in a microscope before a flushing operation is considered finalised. A flowmeter shall be installed to verify flow used during flushing operation. Maximum water content in oil used for flushing shall be less than 500 x 10

-6 (500 ppm).

10.2 Marking

Piping spools or systems that have been chemical cleaned or hot oil flushed shall be marked in a unique manner.

10.3 Documentation

The compliance to specified ISO 4406 requirements shall be documented by relevant laboratory analysis certificates or other acceptable methods. Hot oil flushing documentation shall be fully traceable during the project period of the flushed system. The documentation shall include • a certificate specifying level of cleanness according to ISO 4406, date, location, line numbers and flushing

medium, • a chart from automatic particle counter or the membrane for microscope used to verify particle cleanness.



11 Tightness testing

A tightness test (sensitive leak test) can be performed to check that all external (e.g. mechanical joints, stuffing box) and internal (closed valves) potential leakage points meet the maximum leakage requirements. The tightness test is performed in the commissioning phase, after all construction work is finished and mechanical completion is achieved. The leak test shall be performed with a suitable test medium. The test medium can be divided into the following four types: • Type 1 medium: N2He (1 % He) • Type 2 medium: N2 • Type 3 medium: Air • Type 4 medium: Medium with equal or lower viscosity than actual service medium

The different test medium shall be used in connection with the following services: • Type 1 medium: All services containing toxic or flammable gases or volatile liquids, including first valve

connecting utility systems. Both external and internal leakage points to be checked. • Type 2 medium: Utility systems containing gas where O2 present in the system is not acceptable. Only

external leakage points to be checked. • Type 3 medium: Utility systems containing gas where O2 present in the system is acceptable. Only

external leakage points to be checked. • Type 4 medium: All other services not falling into category type 1, 2 or 3 medium. Only external leakage

points to be checked.

The pressure to be used in the test shall be according to ASME B31.3, ASME PCC2, or other recognized industry standard. Leakage at flanged joints may be evident at much lower pressures when using sensitive leak detection methods; therefore, the minimum test pressure should be specified which enables the test sensitivity requirements to be met. Precautions shall be taken regarding hazard of released energy stored in compressed gas. The pressure shall be maintained for a sufficient length of time to permit visual and/or electronically examination of all external/internal potential leakage points. The maximum allowed leakage rates should be as follows:

• Type 1 medium: Maximum 1 m

3/year (35,3 ft

3/year) for mechanical joints and 5 m

3/year (176,5 ft

3/year) for

stuffing boxes. The requirements for maximum leakage through closed valves set forth by vendor, shall be met.

• Type 2 medium: No visible or audible leakages. Soap water can be used for identification of possible leakages.

• Type 3 medium: No visible or audible leakages. Soap water can be used for identification of possible leakages.

• Type 4 medium: No visible leakages.

The leak test shall be performed according to accepted procedures and the test results shall be documented.

12 System colour coding of piping

12.1 Purpose

In addition to line-numbering, the purpose of having a system for colour coding of piping is to ensure quick recognition of medium and flow direction for any system.

12.2 Types of markers

12.2.1 General

One out of the markers described in 12.2.2 to 12.2.4 shall be used.



12.2.2 Adhesive band/plastic tape glued to the pipe surface

Shall be used • inside living quarters/ administration/ service buildings (HVAC-controlled areas). Shall not be used • inside buildings provided with deluge systems or where water flushing will take place, • on stainless and high-alloyed material and on pipes with a surface temperature of more than 60 °C.

12.2.3 Laminated plastic signs

Shall be used • on all painted carbon steel piping and on insulated piping Shall not be used • on piping in areas where there is a high probability for accumulation of dirt/mud e.g. wellhead area due to

drilling activity, • on stainless and hiqh-alloyed material and on pipes with a surface temperature of more than 60 °C, • on small line sizes with OD 76,2 mm (3 in) and below and tubing 25 mm OD and below.

12.2.4 Laminated plastic signs, mounted in aluminium or stainless steel frame brackets

Shall be used • on all pipes of stainless and hiqh-alloyed materials, • on all pipes with a surface operating temperature of more than 60 °C, • on all pipes of OD 76,2 mm (3 in) and below and all tubing of OD 25 mm and below. Can be used on all pipes and in all areas mentioned in 12.2.2 and 12.2.3.

12.3 Insulated lines

Insulated lines with hidden electrical tracing shall have additional marking band.

12.4 Plastic/rubber lined piping

In addition to the markings described in 12.2.2 to 12.2.4, each spool of all plastic or rubber lined piping shall be marked with the warning "Ikke sveis, innvendig belagt/Do not weld, inner lining". The warning shall be with red letters on a white background.

12.5 Obstruction

The warning tape shall be yellow with black diagonal stripes. This tape is used in conjunction with a standard marker to indicate special precaution requirements.

12.6 Materials of markers

12.6.1 Adhesive tape/band

The adhesive tape/band shall be manufactured from PVC or polypropylene film on which the colour is printed on the reverse (adhesive) side or frontside printed with laminate. The pigmentation shall secure colour retention when exposed to sunshine, oil, grease, steam wash etc. Material shall be suitable for a marine atmosphere and for application in sheltered or exposed positions. The adhesive used shall secure the tape firmly to pure metal surface or to surfaces coated or insulated in accordance with project specifications. Tape shall have an adhesive free from chlorides.

12.6.2 Laminated plastic signs

Laminated plastic signs shall be manufactured of minimum 2 separate units. One layer where the colours and the text are printed, and one transparency layer to protect colours and text. The tag shall be manufactured to cover both right and left flow directions, with right direction on one side and left direction on the opposite side to give full flexibility to installation.



The pigmentation shall secure colour retention when exposed to sunshine, oil, grease and steam wash, etc. The material shall be suitable for a marine atmosphere and for application in sheltered or exposed positions. The laminated tag shall be soft/elastic down to -5 °C. Bending tests shall be documented. Minimum bending radius is 10 to 12 times the thickness of the tag (minimum thickness is 1,5 mm). Laminated PVC-signs to be mounted in brackets made from stainless steel or seawater-proof aluminium.

12.7 Fastening materials

The tape/marker adhesive used shall secure the tape firmly to pure metal surface or to surfaces coated or insulated in accordance with project specifications. The adhesive shall be free from chlorides. The signs shall be fastened to the bare pipe or over insulated pipe by means of non-metallic, UV-resistant PVC-straps and locks. Strap shall be proportionate to the size of the sign. The brackets shall be fastened to the pipes with PVC-covered stainless steel straps and locks. Such straps shall also be used for fastening of signs on all pipes with surface temperature of more than 60 °C

12.8 Marker text

Each marker text shall contain the following information: • Line 1 - Name of flowing medium. • Line 2 - Line number consisting of outside dimension, product code, system number, line sequence

number and pipe classification code. • Line 3 - Short description of function/service (optional) The text shall be in letters and figures of minimum height of 5 mm according to Table 2, but size may be adjusted to fit all required information within the arrow. Longer words can be abbreviated using standard approved abbreviations. However, maximum 2 lines can be used for the abbreviation. On laminated plastic signs, the size of the letters is to be adjusted to fit the size of the sign. The marking shall be with Norwegian text only. Exception is potable water, which shall have both Norwegian and English text, thus: "Drikkevann/Potable water".

12.9 Size and use of markers

Tape markers can be used for all dimension pipes (above 304,8 mm (12 in) OD not recommended) provided it is cut long enough to ensure minimum 10 % overlap on the pipes reverse side. Laminated PVC signs shall be as given in Table 2.

Table 2 ― Size of coloured area on markers

Pipe size inch

Coloured area size mm x mm

Text hight mm

Up to 1 ¾ (Size no. 0) 35 x 110 5 to 7

2 to 3 (Size no. 1) 70 x 110 5 to 7

4 to 8 (Size no. 2) 100 x 155 6 to 8

10 to 16 (Size no. 3) 170 x 305 8 to 10

18 and above (Size no. 4) 260 x 440 10 to 17

The outside diameter of the cladding shall be the basis for determination of the size for insulated lines.



12.10 Positioning of markers

Markers shall be installed with the arrow pointing in the direction of flow. The following special application rules shall be followed: • markers shall be positioned specially considering operational aspects of the plant, and shall be easily

readable from deck, platform or ordinary access way. Ladders, scaffolding or other temporary equipment shall not be needed for identification of markers;

• markers shall be placed at each branching point; • markers shall be placed on each side of bulkheads, decks and other penetration points; • markers shall be positioned on the pipe close to major components of the actual system (vessel, pumps,

etc.); • maximum spacing between markers shall not exceed 10 m; • marker shall be positioned by inlet and outlet of process train; • on elevated pipes, markers shall be positioned adjacent to stairways and platforms; • markers shall be positioned at start and end of pipe racks.

12.11 Valve marking

Each valve (spade, spacer, spectacle blind, inline item and removable special items) shall carry a minimum of one identification tag plate (number plate) in addition to makers tag. The number plate shall be of stainless steel on which the tag number shall be permanently printed. Minimum plate size shall be 20 mm x 50 mm with capital letters of height minimum 5 mm. The tags shall be fastened close to the valve, not onto the valve. This to ensure the tag in position even if the valve is removed or dismantled.

12.12 Fluid description/colour code tabulation

Colour coding shall be in accordance with NS 813 and NS 4054. A detailed coding for systems within oil and gas production is given in NORSOK Z-DP-002.

12.13 Colour coding information

The platform shall have a complete easy readable chart of the used colour coding. The chart shall be mounted, easy to read, at strategic locations in the applicable area.



Annex A (normative)

Alternative test methods

A.1 Scope

This annex defines the alternative test options and methods that may be applied to replace the pressure test requirement for closure welds in hook up spools, and for minor changes and addition in piping system which have already been hydrostatically tested.

A.2 General

All installed piping shall have been pressure tested at the test conditions and medium as specified in accordance with the requirements laid down in ASME B31.3 and this NORSOK standard. All integral welds in a hook-up spool shall have been previously pressure tested. Prior to any alternative testing taking place, acceptance shall be obtained from Company, by issuing a NCR. The NCR shall be the formal documentation of this acceptance. The NCR shall contain • technical/safety reason for deviation, • statement explaining why an alternative test is considered as an acceptable method, • reference to line no., mechanical completion pipe test no. and weld nos., and other relevant system

references, • marked up P&ID, • marked up fabrication isometric drawing, • pipe stress summary of all welds (for lines subject for comprehensive stress analysis), • procedure for internal cleaning of pipe after completed fabrication (when relevant), • alternative test to be performed shall be stated, see A.3, • confirmation of allowable stress, in according to stress analysis, does not exceed 70 % of yield. If allowable stress exceeds 70 % of yield, there are no alternative to hydrostatic test.

A.3 Alternative testing method

In all cases where pressure testing of hook-up spools welds and any minor changes or additions to the piping system will entail an extensive retest, the closure/minor welds may be alternatively tested to the stipulations of this NORSOK standard without being subjected to any pressure test requirements. The qualification of a weld by alternative testing falls into the following two categories which are determined by service/pressure. Alternative I 100 % NDE shall be performed and minimum two different NDE methods shall be employed (i.e. 2x100 % NDE). A certified welding-inspector shall follow up the welding during the entire welding operation. Alternative II The final weld (closure weld) which connects the systems is not required to be pressure tested provided the following requirements have been met: The weld is examined in accordance with ASME B31.3 and passes with • 100 % visual inspection, • 100 % radiographic inspection, • 100 % ultrasonic examination,



• 100 % MPI or dye penetrant as applicable to material. A certified welding inspector shall follow up the welding during the entire welding operation. The above alternatives are clearly depicted in Table A.1 which shall be used as a guideline to define the acceptable alternative testing method.

Table A.1 ― Alternative test methods

Fluids Alternative test method

Normal fluid service (as defined in ASME B31.3) II

Category D fluid service (as defined in ASME B31.3) I

All alternative testing shall be documented with full traceability to the applicable welds.



Annex B (informative)

Requirements for internal treatment of piping after prefabrication and installation before commissioning

Table B.1 represents typical minimum requirements.

Table B.1 ― Requirements for internal treatment of piping after prefabrication and installation before commissioning

Flush Treatment Required cleanliness

Cleaning Verification

Method Prior

Pressure test

Hot oil Flush

Chemical Cleaning

Air Shock (PAS)

ISO 4406 Video Inspection

Drying

Section reference

Service code

System/Service Description

8 11 10 8, 9.7 8, 9.7 9.6

Comments

AI Air instrument AIR X SC X AP Air plant AIR X SC X BA Bulk additives powder (Note 2) AIR X SC X BB Bulk Barite (Note 2) AIR X SC X BC Bulk cement AIR X SC X BD Bulk bentonite (Note 2) AIR X SC X BL Cement, liquid additive Water SC X BM Cement, high/low pressure (Note 2) Water SC CA Chemical, methanol (Note 2) Water SC

CB Chemical, biocide Water SC CC Chemical, catalyst Water SC CD Chemical, scale inhibitor Water X 14/10 SC CE Chemical, de-mulsifier or de-foament Water SC CF Chemical, surface active fluid Water X SC CG Chemical, glycol Water SC CH Chemical, AFFF Water SC CJ Chemical, Ph controller Water X SC CK Chemical, corrosion inhibitor Water X 14/10 SC CN Chemical, mud additive Water SC CO Chemical, oxygen scavanger Water SC CP Chemical, polyelectrolyte / Fokkulant Water SC CR Chemical, refrigerant (Note 2) Water SC CS Chemical, sodium hypochloryte solution Water SC CV Chemical, wax inhibitor Water SC CW Chemical, glycol/water (rich glycol to regen.) Water SC





Method Prior

Pressure test

Hot oil Flush

Chemical Cleaning

Air Shock (PAS)


Drying

Section reference

Service code


8 11 10 8, 9.7 8, 9.7 9.6

Comments

DC Drain, closed Water SC DM Drain, mud Water SC DO Drain, open (Note 4) Water SC DS Drain, sewer/sanitary Water SC DW Drain, water/storm Water SC FC Completion fluid high/low pressure Water SC FJ Fuel, jet Water X 14/10 SC X GA Gas, fire fighting/CO2 N2/CO2 X SC X GF Gas, fuel Water X 14/10 SC X GI Gas, inert N2 X SC X

GW Gas, waste/flue Water SC MB Mud, bulk/solid Water SC MH Mud, high pressure Water SC MK Mud, kill Water SC ML Mud, low pressure Water SC OC Oil, Crude (Note 2) Water SC OF Oil, fuel (diesel oil) Water X SC X Chemical cleaning of critical parts only OH Oil, hydraulic Water X X 14/10 SC X OM Oil, Hot system (Note 2) Water X X SC X OL Oil, lubricating Water X X 14/10 SC X OS Oil, seal Water X X 14/10 SC X PB Process blow down Water X SC Chemical cleaning of critical parts only PL Process hydrocarbons liquid Water X SC Chemical cleaning of critical parts only PT Process two phase Water X SC Chemical cleaning of critical parts only PV Process hydrocarbons vapour Water X SC Chemical cleaning of critical parts only PW Produced water Water SC SP Steam, process Water SC SU Steam, utility/plant Water SC VA Vent, atmospheric (Note 4) Water SC VF Vent, flare Water SC WA Water, sea antiliquifaction Water SC WB Water, sea ballast/grout Water SC WC Water, fresh/glycol – cooling medium Water SC WD Water, fresh potable Water SC WF Water, sea fire fighting Water SC WG Water, grouting systems Water SC WH Water, fresh/glycol – heating medium Water SC WI Water, sea injection Water SC WJ Water, jet Water SC WO Water, oily (Note 2) Water SC





Method Prior

Pressure test

Hot oil Flush

Chemical Cleaning

Air Shock (PAS)


Drying

Section reference

Service code


8 11 10 8, 9.7 8, 9.7 9.6

Comments

WP Water, fresh raw (produced water) Water SC WQ Water, fresh hot (closed circuit) Water SC WS Water, sea Water SC WT Base oil Water SC

NOTE 1 Preservation according to NORSOK Z-006. NOTE 2 Service codes is according to NORSOK Z-006, except for noted service codes which are additions/changes NOTE 3 SC – Inspection by spot check. NOTE 4 No pressure test required, see 8.1.

NORSOK L-004

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Transcript of NORSOK L-004