Gas Industry Standard

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1 Gas Industry Standard GIS/L2:2006 Specification for Steel pipe 21.3 mm to mm outside diameter for operating pressures up to 7 bar (supplementary to BS EN )

3 Contents Foreword Mandatory and non-mandatory requirements Disclaimer Brief history Page ii ii ii iii 1 Scope 1 2 References 1 3 Terms and definitions 1 4 Classification and designation 2 5 Information to be provided by the purchaser 2 6 Manufacturing 2 7 Requirements 2 8 Inspection 3 9 Marking of the pipes 4 10 Coating 4 Annex A (normative) Information to be supplied by the gas transporter 6 Annex B (normative) Information to be provided by the manufacturer/supplier to the purchaser 7 Bibliography Error! Bookmark not defined. Table 1 Standard pipe diameter, thickness and type combinations 5 Table B.1 Table of gas transporter requirements 7 i

4 Foreword Gas Industry Standards (GIS) are revised, when necessary, by the issue of new editions. Users should ensure that they are in possession of the latest edition. Contractors and other users external to Gas Transporters should direct their requests for copies of a GIS to the department or group responsible for the initial issue of their contract documentation. Comments and queries regarding the technical content of this document should be directed in the first instance to the contract department of the Gas Transporter responsible for the initial issue of their contract documentation. This standard calls for the use of procedures that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and does not absolve the user from legal obligations relating to health and safety at any stage. Compliance with this engineering document does not confer immunity from prosecution for breach of statutory or other legal obligations. Mandatory and non-mandatory requirements For the purposes of a GIS the following auxiliary verbs have the meanings indicated: can may shall should Disclaimer indicates a physical possibility; indicates an option that is not mandatory; indicates a GIS requirement; indicates best practice and is the preferred option. If an alternative method is used then a suitable and sufficient risk assessment needs to be completed to show that the alternative method delivers the same, or better, level of protection. This engineering document is provided for use by Gas Transporters and such of their contractors as are obliged by the terms of their contracts to comply with this engineering document. Where this engineering document is used by any other party, it is the responsibility of that party to ensure that the engineering document is correctly applied. ii

5 Brief history First published as BGC/PS/ L2 Amendment No.1 published Amendment No.2 published Amendment No.3 published Amended issue published as GBE/L2 Amendment No.1 published Editorial update to reflect demerger November 2000 Editorial update to reflect merger October 2002 Editorial update to comply with GRM Edited by BSI in accordance with BS 0-3:1997 Reviewed on behalf of the technical standard forum or Gas National collaboration forum by BSI August 1983 September 1985 June 1986 October 1989 November 1992 September 1994 June 2001 November 2002 August 2004 August 2006 September 2013 National Grid, Northern Gas Networks, Scotia Gas Networks, and Wales and West Utilities. This Gas Industry Standard is copyright and must not be reproduced in whole or in part by any means without the approval in writing of either National Grid, Northern Gas Networks, Scotia Gas Networks, or Wales and West Utilities. iii

7 1 Scope This Gas Industry standard covers steel pipe sizes from 21.3 mm to mm outside diameter for maximum operating pressures up to 7 bar. Standard steel pipe dimensions are given in Table 1. 2 References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Formal standards BS 21, Specification for pipe threads for tubes and fittings where pressure-tight joints are made on the threads (metric dimensions). BS EN :2001, Welding Recommendations for welding of metallic materials Part 2: Arc welding of ferritic steels. BS EN 10204:2004, Metallic materials Types of inspection documents. BS EN :1998, Steel pipes for pipelines for combustible fluids Technical delivery conditions Part 1: Pipes of requirement class A. BS EN , Seamless steel tubes for pressure purposes Part 1: Technical delivery conditions. BS EN , Welded steel tubes for pressure purposes Technical delivery conditions Part 1: Non-alloy steel tubes with specified room temperature properties. BS EN 10226, Pipe threads where pressure tight joints are made on the threads Taper external threads and parallel internal threads Dimensions, tolerances and designation. Individual Gas Distribution Network Standards */SP/CM1, Procedure for internal coating operations for steel line pipe and fittings. */SP/CM2, Internal coating materials for steel line pipe and fittings. */SP/CW4, Specification for polyethylene cladding on steel pipe. */SP/CW5, The selection and application of field applied external pipework coatings. */SP/CW6-1, The external protection of steel line pipe and fittings using fusion bonded powder and associated coating systems Part 1: Requirements for coating materials and method of test. */SP/CW6-2, The external protection of steel line pipe and fittings using fusion bonded powder and associated coating systems Part 2: Factory applied coatings. */SP/P1, Specification for the welding of steel pipe for distribution systems and installations (operating at pressures below 7 bar). */PR/ND*/1, Carrying out non destructive testing of plant and equipment. * = Denotes each gas distribution network reference 3 Terms and definitions For the purposes of this document, the terms and definitions given in BS EN apply. 1

8 4 Classification and designation See Clause 4 of BS EN : Information to be provided by the purchaser 5.1 Required information See 5.1 of BS EN : Other information See Annex B. 6 Manufacturing 6.1 General No change to BS EN Pipe manufacturing Pipe type shall be as indicated in Table 1. Where more than one option is indicated for a given pipe size, the choice of pipe type is left to the manufacturer unless otherwise indicated by the gas transporter at the time of order. SAWL pipe manufactured with two weld seams is not permitted. 6.3 Jointers The delivery of jointers is not permitted. 6.4 Magnetic particle test for EW pipe For EW pipe, a magnetic particle test shall be carried out in accordance with */PR/ND*/1, on each end of the strip of every coil, either when the strip is in the flat form or in the form of pipes. The indication of any lamination or other defect may be cause for rejection of the entire strip or of all pipes manufactured from the same strip. 7 Requirements 7.1 General Steel pipe supplied in accordance with this standard shall be of material grade L245GA and shall in all respects conform to the requirements of BS EN , except where supplemented or amended by the requirements of this Gas Industry Standard. The requirements detailed in this Gas Industry Standard shall take precedence over BS EN Add the following: Pipe shall be of Grade L245GA. Steel pipes from 15 mm to 50 mm nominal sizes (21.3 mm to 60.3 mm outside diameters) are intended for socket welding in accordance with */SP/P1 and shall be supplied with square ends. These sizes of steel pipe are also suitable for threading conforming to BS 21 and BS EN Steel pipe greater than 50 mm nominal size are intended for full penetration welding in accordance with */SP/P1 and shall be supplied with a weld bevel as detailed in of BS EN :

9 7.2 Chemical composition Cast analysis and Product analysis GIS/L2:2006 The maximum sulphur content for EW pipe shall not exceed % and for other pipe types shall not exceed 0.02 %. The boron content for all pipe types shall not exceed %. The carbon equivalent shall not exceed 0.43 % based on the formula given in BS EN :2001, Annex C method A. The above limits shall apply to both cast and product analyses. 7.6 Dimensions, masses and tolerances Tolerances on the pipe Diameter and out of roundness Except for seamless pipes, Table 6 of BS EN :1998 shall be modified as follows: Outside diameter D mm D 610 Diameter tolerance Pipe except the end 0,5 % D (max. = 3 mm min. = 0,5 mm) Pipe end 0,3 % D (max. = 1,1 mm min. = 0,5 mm) 1) 610 < D 914 1,3 mm 1) 914 < D < mm 1,6 mm 1) Out-of-roundness Pipe except the end 1,5 % (1,0 % for SAW pipe) Pipe end D mm 1,6 mm 1) 1,5 % 1 % (D/T 75) 1,25 % (D/T > 75) 1) See options O9 and O10. The other notes in Table 9 apply. 1 % For SAW pipe, both ends of every pipe shall be additionally checked using an internal ring gauge, the external diameter of which shall be 6 mm ± 0.25 mm less than the nominal inside diameter of the pipe, and for mm outside diameter pipe, where the D/T ratio exceeds 75 for this pipe size, the internal ring gauge external diameter shall be 7.4 mm ± 0.25 mm less than the nominal inside diameter of the pipe Length The length group shall be r2 of BS EN :1998, Table 8. 8 Inspection 8.1 Types of inspection and inspection documents The inspection document requirement shall be in accordance with type 3.1 of BS EN 10204:

10 9 Marking of the pipes 9.1 General marking Delete: e)1) the mark of the inspection representative Add: i) the BUYER s order and item number; ii) GIS/L2; iii) pipe type i.e. SAWL or SAWH, S (seamless) or EW (as applicable); iv) outside diameter and wall thickness in millimetres; v) cast number; vi) pipe length in metres; Delete existing text and replace with: For pipe sizes up to and including 457 mm outside diameter, as an alternative to paint stencil marking, low stress dot matrix stamping may be employed positioned at one the end of the pipe within the coating cut back area. For EW pipe low stress dot matrix stamping shall be adjacent to the weld seam. In all cases, the area to be stamped shall be clean and free from paint, other coating and rust. Any original coating shall be replaced after stamping. Alternative procedures for die stamping may be submitted for the approval of the gas transporter. 10 Coating The heading of Clause 10 of BS EN :1998 is to be amended to that shown above, and text replaced with the following Internal protection All pipes shall be internally coated in accordance with the requirements of */SP/CM1 and */SP/CM External protection All pipes of size greater than mm outside diameter shall be externally coated in accordance with the requirements of */SP/CW6-1 and */SP/CW6-2. Pipes mm to mm inclusive outside diameter shall also be externally coated in accordance with the requirements of */SP/CW6-1 and */SP/CW6-2, unless at the time of order it is indicated by the gas transporter that external coating is to be field applied. In this case, the pipe is to be supplied with a temporary external coating to prevent rusting in transit and storage. This temporary coating shall be an epoxy holding primer or equivalent and not a grease based coating. The subsequent field applied coating shall be a spray applied multi-component liquid in accordance with the requirements of */SP/CW Weld end preparation protection All weld end preparations shall be protected against corrosion using a method approved by the gas transporter. Protection against mechanical damage of weld end preparations shall also be applied if specified by the gas transporter. 4

11 Nominal size mm Table 1 Standard pipe diameter, thickness and type combinations Outside diameter mm Nominal wall thickness EW/S EW/S EW/S EW/S EW/S EW/S EW/S EW/S EW/S mm EW EW EW Permitted pipe types EW/SAWL/SAWH EW/SAWL/SAWH EW/SAWL/SAWH SAWL/SAWH SAWL/SAWH SAWL/SAWH SAWL/SAWH NOTE 1 Pipe grade for all sizes indicated above shall be L245GA. NOTE 2 Pipe types are as follows: a) S seamless; b) EW electric welded; 1) (HFW high frequency welded type in BS EN is also permitted); 2) this category equates to the ERW pipe type in earlier versions of this Gas Industry Standard; c) SAWL submerged arc welded (longitudinal seam); d) SAWH submerged arc welded (helical seam). 5

12 Annex A (normative) Information to be supplied by the gas transporter The gas transporter shall state the following in the enquiry and order: a) the number of this standard; b) the pipe nominal size; c) the quantity in metres or number of lengths; d) whether protection of weld end preparations against mechanical damage is required; e) for pipe of 15 mm and 50 mm inclusive size, whether a product analysis is required. Additionally, for pipes of 15 mm to 150 mm inclusive nominal size where the standard cladding in accordance with */SP/CW4 is not required, the gas transporter shall specify varnished pipe. 6

13 Annex B (normative) Information to be provided by the manufacturer/supplier to the purchaser Reference BS EN Table B.1 Table of gas transporter requirements Item (clause reference of BS EN ) Required agreement (indicated by M in BS EN ): a.1 Diameter tolerance for seamless > 25 mm wall thickness a.2 Diameter tolerance for pipe > mm outside diameter a.3 Party to issue inspection document Gas transporter requirement (clause reference of this standard) Not applicable Not applicable Not applicable Unless agreed left to the discretion of the manufacturer (indicated by U in BS EN ): b.1 Process of manufacture for welded pipe (see 6.2) b.2 Choice of heat treatment condition (see 6.3) b.3 Choice of welding process for jointers (see B.1) b.4 Radiographic inspection for the detection of longitudinal imperfections (see D.4.2.a) Optional agreement (indicated by O in BS EN ): c.1 Manufacture of SAWL pipe with two seams (see 6.2) Refer to Table 1 of this standard for permitted pipe types. See also 6.2 of this standard Seamless pipe in the quenched and tempered condition shall not be supplied unless agreed by the gas transporter Not applicable Required Not permitted c.2 Delivery of jointers (see 6.6) Not permitted c.3 Application of the diameter tolerance to the ID (Table 6, note 3) c.4 Application of the diameter tolerance to the OD (Table 6, note 4) c.5 Special bevel configuration (see ) c.6 Threaded ends or belled ends (see ) c.7 Offset of strip end welds (Table 10, note 1) The tolerance for pipe diameter and out of roundness shall apply to the inside diameter for outside diameter > 210 mm As above Bevel configuration shall be as given in BS EN unless specifically requested otherwise by the gas transporter Threaded ends shall only be supplied when specifically requested by the gas transporter Other offset tolerances will not be accepted unless specifically agreed by the gas transporter 7

14 Reference BS EN Table B.1 Table of gas transporter requirements Item (clause reference of BS EN ) Required agreement (indicated by M in BS EN ): c.8 Test piece direction (Table 13, note 2) c.9 Use of round test pieces (see ) c.10 Use of flattened and heat treated test coupons (see ) c.11 Non-destructive leak tightness test instead of hydrostatic test (see ) c.12 Use of special devices for measuring the pipe diameter (see ) c.13 Use of cold die stamping (see 9.1.3) Gas transporter requirement (clause reference of this standard) The orientation for tensile test pieces shall be transverse for seamless pipe 210 mm Not permitted Test coupons may only be taken before heat treatment if the procedures that provide traceability and the treatment conditions of the test coupons have been approved by the gas transporter Not permitted c.14 Special marking (see 9.2) Not applicable c.15 Coating and lining (see Clause 10) c.16 Degree of staggering of weld seams in jointers (see B.1) c.17 Verification of the quality requirement for laminations (see D.2.3) c.18 Use of fixed depth notches for equipment calibration (see D.4.1.1d) c.19 Use of hole penetrameters instead of the ISO wire penetrameter (see D.4.3.1a) c.20 Use of fluoroscopic inspection (see D.4.3.1b) The method of diameter tolerance measurement for both pipe body and pipe ends shall be by circumferential tape Die stamping permitted. Refer to of this standard Refer to Clause 10 of this standard for internal and external coating requirement. Note for pipe sizes 21.3 mm to mm inclusive outside diameter, the gas transporter is to inform supplier at time of order where external coating is to be an on-site spray applied multi-component liquid conforming to */SP/CW5 rather than factory coated conforming to */SP/CW6 Not applicable Required Not permitted Not permitted Not permitted 8

BS EN Welded steel tubes for pressure purposes Technical delivery conditions Non alloy steel tubes with specified room temperature properties

BS EN Welded steel tubes for pressure purposes Technical delivery conditions Non alloy steel tubes with specified room temperature properties BS EN 10217 1. Welded steel tubes for pressure purposes Technical delivery conditions Non alloy steel tubes with specified room temperature properties 1 SCOPE This Part of EN 10217 specifies the technical