Steel Piping and Fittings for Refrigeration Duties

Transcription

1 Steel Piping and Fittings for Refrigeration Duties Introduction The purpose of this standard is to bring together the information relative to design, manufacture and installation of refrigeration carbon and stainless steel pipework on all Star specified refrigeration equipment. The application of thin wall stainless steel (TWSS) piping and fittings for glycol and water duties and for pressure relief discharge lines are treated as special cases and are covered in Star Standard Specifications No. 150 and 156. On contracts where an application standard is specified by a client or by an inspecting authority on a client s behalf that standard will take precedence over the Star standard. Pressure testing on vessels and packaged unit piping will be carried out in accordance with Star Standard Specifications No s 113 and 125. This specification covers: Section Title Steel Pipe and Fittings Pipe Specification Pipework Design and Allowable Pressures Butt Weld Fittings Socket Weld Fittings Flanges Saddle Bosses Purchasing Requirements Installation Standards, Welding Standards and Welding Processes Installation Standards Welding Standards Welding Processes Inspection Screwed Joints and Compression Fittings Screw Thread Joints Compression Fittings Refrigeration Valves and Controls Refrigeration Stop Valves Bore Match L:\Standard Specifications\SS024.K.Steel Piping.doc Page 1 of 16

2 1.0 Steel Pipe and Pipe Fittings for Welded Pipework 1.1 Pipe Specification Carbon Steel Pipe Specification The selection of material specification for carbon steel pipe will be taken from Figure 1 of this standard. In general, the pipe material specification used in Star installations and units will be ASTM A106 GR.B or ERW API5L (where available). Where we are using carbon steel and where the working conditions are such that there will be a combination of high pressure (i.e. above 4 Bar (G)) and low temperature (i.e. below 29.0ºC) the pipe material used will be ASTM A333 GR6. Where the pressure is less than 4 Bar (G) ASME B31.3 allows the use of ASTM A106B material down to -45C The pipe dimension specification for pipe from 17.1mm OD (3/8 NB) to 168.3mm OD (6 NB) will be ANSI B Sch 40 (BS1600) with the following dimensions and weights: Table for ANSI.B.36.10: Sch 40 (BS1600) Outside Diameter mm Nominal Bore ins Wall Thickness mm Weight kg/m / ½ ¾ ¼ ½ ½ For pipe 219.1mm OD (8 NB) or above, Sch 20 will be specified with the following dimensions and weights: Table for ANSI.B.36.10: Sch 20 Outside Diameter mm Nominal Bore ins Wall Thickness mm Weight kg/m L:\Standard Specifications\SS024.K.Steel Piping.doc Page 2 of 16

3 Screwed pipework and fittings to EN10255:2004 (formerly BS 1387) and BS3799 may be used for water, brine and glycol pipework with design pressures up to 10 Bar(G). Caution: Where pipework to EN10255 and fittings to BS EN and BS EN (formerly BS 1965) ( Blue Band pipework) are to be used they must be selected to give correct matches on bore and outside diameter to satisfy the welding specifications To comply with the painting specification we may choose to purchase pipework in a cleaned and primed condition. If different grades of pipework are to be used on the same project they should be pre-primed in different colours to avoid confusion and mistakes on site Mapress pipework system may be used for small bore low pressure drains Stainless Steel Pipe Specification The stainless steel material specification shall be ASTM A312 grade 316L or 304L. 1.2 Pipework Design and Allowable Pressures Allowable Pressures for Carbon Steel Pipe Table of carbon steel pipe diameters up to 150NB and maximum allowable pressures Nominal Pipe Size (ins) Nominal Pipe Size (mm) API5L GrB ASTMA106 & A333 Gr 6 Sch 40 Bore (mm) Maximum Allowable Pressure (Bar(G)) API5L GrB ASTMA106 & A333 Gr 6 Sch 80 Bore (mm) Maximum Allowable Pressure (Bar(G)) ⅜ ½ ¾ ¼ ½ ½ L:\Standard Specifications\SS024.K.Steel Piping.doc Page 3 of 16

4 Table of carbon steel pipe diameters 200NB and above maximum allowable pressures Nominal Pipe Size (ins) Nominal Pipe Size (mm) API5L GrB ASTMA106 & A333 Gr 6 Sch 20 Bore (mm) Maximum Allowable Pressure (Bar(G)) API5L GrB ASTMA106 & A333 Gr 6 Sch 40 Bore (mm) Maximum Allowable Pressure (Bar(G)) Allowable pressures for stainless steel pipe Table of stainless steel pipe diameters up to 300NB and maximum allowable pressures Nominal Pipe Size Nominal Pipe Size 304L & 316L Sch 40 Maximum Allowable Pressure 304L & 316L Sch 80 Maximum Allowable Pressure (ins) (mm) Bore (mm) (Bar(G)) Bore (mm) (Bar(G)) ½ ¾ ¼ ½ ½ General Arrangement All pipework between anchors or other restraint points (eg connections and branches) shall be arranged and supported to allow normal movement due to expansion and contraction without the need for expansion joints. All connections are to be made to headers and equipment using formed fittings, except as below: Cold Formed Bends Cold formed bends, instead of forged bends, will be allowed on carbon steel pipework 40NB or less. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 4 of 16

5 1.2.5 Stab-ins Stab-ins will be allowed according to the following Table and notes, provided the branch size is greater than 25NB. The designs include a 10% allowance to cover system pressure tests at 1.1 times the allowable pressure and a further safety factor of 10%. Table of maximum allowable stab in sizes Header NB Maximum Branch Size NB Allowable Pressure/Application 52.0 Bar (G) and 65.0 Bar (G) (1) 25.5 Bar (G) 10.0 Bar (G) on Glycol Notes (1) For the case of 52.0 Bar (G) and 65.0 Bar (G) allowable pressure, all pipes (ie both header and branch) will be SCH 40 thickness regardless of diameter whereas for the other cases SS53 Sizing of Refrigerant Pipe Lines allows SCH 20 thicknesses for header and branch pipe sizes 200 NB and above. (2) All branches will be perpendicular to the header and on the centre line. (3) A full penetration weld as per Star standard drawing type C or type E is required. (4) Olets will be allowed, instead of T pieces, for branches of 25NB or less where the main pipe is at least two standard pipe sizes larger than the branch. Where stab-in branch connections are permitted, the end of the branch pipe shall be shaped to match the internal curvature of the header pipe and the protrusion into the header pipe shall be 3mm all round, not significantly more. Refer to example figures below (extract from BS 2633). Root run to be dressed to clean metal then seal welded. (a) Single-bevel preparation Root run to be dressed to clean metal then seal welded. (b) Single-J preparation Figure g f (max.) l r mm mm mm mm (a) (b) Typical preparation and assembly of stab-in branches L:\Standard Specifications\SS024.K.Steel Piping.doc Page 5 of 16

6 1.2.6 Minimum Distance Between Welds The minimum distance between the toe of adjacent welds shall be 25mm. Where this is impractical, this should be agreed with the Production Department on a case by case basis Pipe Closures Welded dished end caps shall be used for closures at ends of all refrigerant pipework. Flat closures are not allowed. 1.3 Butt Weld Pipe Fittings Carbon steel fittings The selection of material specification for butt welded pipe fittings, bends, tees, reducers and caps will be taken from Figure 1 of this standard. In general, the material specification for carbon steel butt welded pipe fittings, bends, tees, reducers and caps used in Star installations and units will be ASTM A234 WPB where the pipe is ASTM A106 Gr B or ERW API 5L. Where the working conditions are such that there will be a combination of high pressure (i.e. above 4 Bar (G)) and low temperature (i.e. below 29.0ºC), the material used will be ASTM A420 WPL6 in all cases where the pipe is ASTM A333 Gr The dimensions of all butt weld fittings will confirm to ANSI B16.9 (BS1640). For all pipe work from 42.2mm OD (1¼ NB) to 168.3mm OD (6 NB) Sch 40/STD fittings for pipework will be specified. For 219.1mm OD (8 NB) and above, Sch 20 fittings will be specified Stainless steel fittings In general, the material specification for stainless steel butt welded pipe fittings, bends, tees, reducers and caps will be ASTM A Socket Weld Fittings Carbon steel socket weld fittings Socket weld fittings will be used for all pipework up to and including 48.3mm OD (1½ NB) where practical. For the avoidance of doubt, it is not considered practical to use socket weld fittings on DIN Standard pipework. The dimensions of the fittings will conform to ANSI B16.11 (BS3799). The selection of material will be taken from Figure 1. In general, the fitting material will be ASTM A105. The rotor oil feed pipework on Vilter compressor packs will be a special exception and butt welded as standard. Contract specific requests for butt weld connections will take precedence over the requirement for socket weld fittings in this specification. Where working conditions are such that there will be a combination of high pressure (over 4 Bar(G)) and low temperature (below 29.0ºC), the material used will be ASTM A350GR.LF2. Note: Where the end of a pressure carrying pipe is to be sealed, a standard butt weld or socket weld cap fitting must be used. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 6 of 16

7 1.4.2 Stainless steel socket weld fittings Socket weld fittings material will be ASTM A Flanges Carbon steel flanges All flanges will be to ASME B16.5 (equivalent to BS 1560 or its direct replacement BS EN ) Class 300 (unless higher pressure is required or DIN flange to suit line component). The format of the flanges for pipe sizes up to and including 33.4mm OD will be socket weld raised face and from 42.4mm OD slip on raised face The selection of material will be taken from Figure 1. In general, flange material will be ASTM A105. Where the working conditions are such that there will be a combination of high pressure (above 4 Bar(G)) and low temperature (below 29.0ºC), the flange material used will be ASTM A350 LF Flange bolt hole dimensions are given in imperial units only in ASME B16.5. However, BS 1560 and BS EN (equivalent to ASME B16.5) do not preclude the use of metric bolts and provide tables of comparable imperial and metric nominal bolt sizes. Due to better availability, Star specify metric bolting as standard. Several similar standards are available which apply to metric bolts. Due to better availability, Star specify metric bolting in accordance with DIN-931 M1.6 to M39 Hexagon Head Bolts, Screws and Nuts. Acceptable alternative standards are BS EN ISO 4014 Hexagon Head Bolts (direct equivalent of DIN 931) and BS 3692 ISO Metric Precision Hexagon Bolts, Screws and Nuts. Bolts for use in systems with design temperatures down to -50 C shall have mechanical properties compliant with grade 8.8 of BS EN ISO Mechanical Properties of Fasteners Made of Carbon Steel and Alloy Steel. Several similar standards are available which apply to metric nuts. Due to better availability, Star specify metric nuts in accordance with DIN 934 Hexagon Nuts with Metric Coarse and Fine Pitch Thread. Acceptable alternative standards are BS EN ISO 4032 and 8673 (direct equivalents of DIN 934) and BS 3692 ISO Metric Precision Hexagon Bolts, Screws and Nuts. Nuts shall have mechanical properties compliant with grade 8 of ISO (identical properties are also given in BS 3692). Marking of bolts and nuts shall be in accordance with BS EN ISO (bolts) and BS EN ISO (nuts). Where bolts and nuts are specified to DIN standards, the marking requirements of DIN 267 are acceptable (similar to ISO 898 parts 1 and 2). Bolts for use in systems with design temperatures below -50 C shall have mechanical properties compliant with grade A2 70 of BS EN ISO Mechanical Properties of Corrosion Resistant Stainless Steel Fasteners, Bolts, Screws and Studs. Nuts shall have mechanical properties in accordance with BS EN ISO L:\Standard Specifications\SS024.K.Steel Piping.doc Page 7 of 16

8 Comparable metric and imperial bolt sizes are given in the table below (as given in BS EN 1759). Imperial ½ ⅝ ¾ ⅞ 1 1⅛ 1¼ 1⅜ 1½ Metric M14 M16 M20 M24 M27 M30 M33 M36 M39 The following table shows the bolt sizes to use for Class 150, 300 and 600 flanges. Imperial sizes are also given for information. Nominal Flange Size Nominal Diameter of Bolts Class 150 Class 300 Class 600 mm ins Metric Imperial Metric Imperial Metric Imperial 15 ½ M14 ½ M14 ½ M14 ½ 20 ¾ M14 ½ M16 ⅝ M16 ⅝ 25 1 M14 ½ M16 ⅝ M16 ⅝ 32 1¼ M14 ½ M16 ⅝ M16 ⅝ 40 1½ M14 ½ M20 ¾ M20 ¾ 50 2 M16 ⅝ M16 ⅝ M16 ⅝ 65 2½ M16 ⅝ M20 ¾ M20 ¾ 80 3 M16 ⅝ M20 ¾ M20 ¾ M16 ⅝ M20 ¾ M24 ⅞ M20 ¾ M20 ¾ M M20 ¾ M20 ¾ M M20 ¾ M24 ⅞ M30 1⅛ M24 ⅞ M27 1 M33 1¼ M24 ⅞ M30 1⅛ M33 1¼ M27 1 M30 1⅛ M36 1⅜ M27 1 M33 1¼ M39 1½ Where use of imperial bolting is a strict customer requirement then the applicable standard must be agreed with the customer and Star s Production Department. Where strict compliance with ASME B16.5 is specified, then for applications with a minimum design temperature no lower than -48 C, mechanical properties shall be compliant with ASTM A193 Grade B7 and for lower temperature applications mechanical properties shall be compliant with ASTM A320 Grade L7. Bolts should be specified in accordance with ASME B and nuts should be specified in accordance with ASME B Stainless steel flanges Flange material will be ASTM A Pipe Saddle Bosses (e.g. Weldolets/Threadolets) Carbon steel bosses Saddle Boss fittings will be used on all pipe work where a screwed stud coupling or threaded insert is to be fitted. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 8 of 16

9 The dimensions of saddle fittings will be to ANSI B31.1 In general, the saddle fittings material specification used in Star installations and units will be ASTM A105. Where working conditions are such that there will be a combination of high pressure (i.e. above 4 Bar(G)) and low temperature (i.e. below 29.0ºC), the material will be ASTM A350 LF The thread of the fitting will be ANSI B National Standard Tape Pipe Thread NPT If a non standard boss is required on an installation it will be manufactured from bar material BS A Stainless steel bosses Boss material will be ASTM A Purchasing Requirements All orders for the following carbon steel material grades will state our requirement for a maximum carbon content (C MAX) of 0.25%: Pipe ASTM A106 GRB ERW API5L ASTM A333 GR6 Butt Weld Fitting ASTM A234 WPB ASTM A420 WPL6 Forgings, Flanges, Socket Fittings, Saddle Fittings ASTM A105 ASTM A350LF Material Certification Material certification for all pipe, fittings and flanges is required. The material must be marked with the test certificate reference to ensure conformity and traceability. The certificates will be filed with the installation records by the Branch Manager or, in the case of package units, by the Works Office Painting All carbon steel pipe purchased for Star installations and units will be externally cleaned and prime painted. The work may be carried out by the pipe stockist on our behalf. Alternatively, the purchaser may arrange for this work to be carried out by a third party Paint Specification All carbon steel pipe will be shot blasted externally to a minimum standard SA2½ (BS7079). After blast cleaning all pipes will be blown clear. After cleaning, the pipe is to be capped and externally painted with one 20 micron coat of METAGARD G250 red oxide primer for A106 pipe and grey oxide primer for A333 pipe (W & J Leigh & Co) or alternative material agreed in writing on a contract specific basis. The pipe will be identified with the material certificate reference number. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 9 of 16

10 2.0 Installation Standards, Welding Standards, Welding Processes and Inspection 2.1 Installation Standards The application standards for all carbon steel pipe work on Star installations and package units is dependent on the system design and will be as follows: System Design Pressure According to the Diagram of Connections Up to and including 17 Bar (G) Over 17 Bar (G) Application Standard BS Class II Category A. ARC welding of carbon steel pipework for carrying fluids BS2633:1987 Class I. ARC welding of carbon steel pipework for carrying fluids For all primary refrigerant stainless steel pipework above a system design pressure of 8 Bar (G) the application standard shall be BS EN ISO (Welding fusion welded joints in steel, nickel, titanium and their alloys quality level C). For lower pressure primary refrigerant stainless steel pipework or for secondary fluids refer to Star Standard Specifications 150 and Welding Standards All welding on pressure carrying pipework on Star installations and package units will be carried out to verified procedures to BS EN288, Pt 3: Specification and qualification of welding processes for metallic materials or its direct replacement BS EN ISO : Other recognised standards may be used if it is agreed in writing with Star s Production Department on a contract specific basis. The procedures will cover the range and type of welds required for the pipework being welded All welders working on pressure carrying pipework on Star installations and units will have current verified approval to BS EN287, Pt 1:1992 (or 2001) - Qualification testing of welders for fusion welding. The approvals will cover the range and type of welds required for the pipework being welded Other national welding standards such as ASME VIII may be accepted, provided welding procedures and current qualifications of the welders cover the range and type of welds required for pipework being welded. Where it is proposed that an alternative standard is used, this should be agreed with the Technical Department and the accredited inspection authority where appropriate. 2.3 Welding Processes All butt welded joints will be rooted using tungsten inert gas arc welding (TIG). The welds will be completed using TIG or manual metallic arc welding (MMA) Oxyacetylene welding is not allowed. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 10 of 16

11 2.4 Inspection Requirements The requirements in this section are the minimum to be used on Star installations and packaged units. The requirements apply to all welded pipe including relief valve vent pipework, glycol and water piping (refer to Standard Specifications 150 and 156 for inspection requirements where the water, glycol or relief valve vent pipework is thin wall stainless steel) Visual inspection of all pipework welds to ensure conformity with the requirements of the application standard being used Non destructive inspection of butt welds will be carried out. The percentage of welds subjected to non destructive inspection will be as follows: Application Standard BS2633:1987 BS2971:1991 BS EN ISO 5817:2014 (for stainless steel) 10% of each welders production of butt welds 10% of each welders production of butt welds 10% of each welders production of butt welds In addition to the above inspection requirements, all butt weld and socket weld end caps on headers and distribution manifolds on hot gas defrost pipework will be subjected to non destructive inspection (NDI) Radiographic inspection to BS2910 or its direct replacement BS EN ISO : 2013 will be used for butt welds. Ultrasonic inspection to BS3923 Pt 1 or its direct replacement BS EN ISO : 2010 may be used, provided the procedure used is suitable for the material thickness being inspected. Other recognised standards may be used if it is agreed in writing with Star s Production Department on a contract specific basis. For socket welded joints where inspection is required, Magnetic Particle Inspection (MPI) will be used Defect limitation and any rectification work required will be in accordance with the application standard being used for the inspected pipework All non destructive inspection will be carried out to approved procedures and the interpretation of the inspection report will be by qualified personnel. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 11 of 16

12 2.4.2 Records A weld identification record will be created each time a non destructive inspection is carried out. The record will have the following information: 1. Star order number and job number 2. Application standard to be used for interpretation of NDI results 3. Weld identification reference 4. Weld location this may require a location sketch. 5. Welder s identification reference All non destructive test records and radiographs will record: 1. Date 2. Job number 3. Weld identification reference 4. Welder identification reference The weld identification record and the non destructive inspection records will be filed together and kept with the installation records by the Branch Manager or package unit records by the Works Office It has been agreed with Lloyds that there is no requirement to retain a copy of the radiograph. However, this will be retained for all petrochemical contracts. 3.0 Screwed Joints and Compression Fittings 3.1 Screw Thread Joints Screw thread joints will be used in conjunction with stud couplings, gauge and instrument valves and small bore pipework. In general, the screw thread will be ANSI B NPT. 3.2 Compression Fittings Use of compression fittings will be restricted to pipe sizes 42mm OD and below The fitting used will be to DIN 2353 and will be steel L Series. The preferred compression fittings will be Ermeto EO Range L Series. An alternative and interchangeable fitting is EMB L Series The preferred size range of compression fittings will be: 10mm ¼ NB approx 28mm ¾ NB approx 15mm 3/8 NB approx 35mm 1 NB approx 22mm ½ NB approx 42mm 1¼ NB approx Metric OD pipe for use with DIN Standard L Series fitting will be to DIN2391/C material ST35.4/ST37.4. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 12 of 16

13 3.2.5 Pipe dimensions will be: OD Wall Thickness (minimum) The assembly and installation of compression fittings will be in accordance with the manufacturer s recommendations. 4.0 Refrigeration Valves and Controls 4.1 Refrigeration Stop Valves The selection of stop valve format for welded pipework is applicable for the DANVALVE, Robinet and other similar valve ranges The selection of valve terminations will be as follows: OD mm Pipe Size NB ins Valve Size Termination Format Weld Type /8 10 ANSI B Socket 21.3 ½ 15 ANSI B Socket 26.7 ¾ 20 ANSI B Socket ANSI B Socket ¼ 32 ANSI B Socket ½ 40 ANSI Sch 40 Butt ANSI Sch 40 Butt ½ 65 ANSI Sch 40 Butt ANSI Sch 40 Butt ANSI Sch 40 Butt ANSI Sch 40 Butt ANSI Sch 40 Butt ANSI Sch 20* Butt ANSI Sch 20* Butt ANSI Sch 20* Butt ANSI Sch 20* Butt *Note that for Robinet (RFF) valves, these are not available with ANSI Sch 20 connections and so should be specified with DIN connections which more closely matches the bore of the Sch 20 pipework Seal Caps All manually operated stop valves will be fitted with seal caps regardless of refrigerant unless specified otherwise on a contract specific basis. On low temperature insulated pipework where polystyrene, polyurethane or similar is used, the valves will have an extended spindle or long bonnet and seal cap. L:\Standard Specifications\SS024.K.Steel Piping.doc Page 13 of 16

14 4.2 Bore Match The matching of the bore of a valve or a mating flange must be checked to ensure that the bore variation is generally in line with the application. In some cases we may choose to fit a transition piece so that a butt weld will conform to the requirements of the application standard. Alternatively, the works may choose to machine the flange to suit the pipe Typical limits for bore difference and alignment using TIG welding with a root gap: Over Up to and including BS2633 (1) BS2971 (2) 1.0mm 1.5mm 2.5mm (1) Class I arc welding of ferritic steel pipework for carrying fluids use when design pressure is greater than 17 Bar (G) (refer to section 2.1.1). (2) Class II arc welding of carbon steel pipework for carrying fluids use when design pressure is less than or equal to 17 Bar (G) (refer to section 2.1.1) L:\Standard Specifications\SS024.K.Steel Piping.doc Page 14 of 16

15 Date Issue Originator Changes Sections Affected August DMF July DJH May DJH March DJH July 2002 E DJH October 2003 F DJH 05/07/06 G DJH Now includes designs to 65.0 bar allowable pressure bar stab-in into 100NB header now limited to 65NB (was 80NB). Socket weld fittings allowed up to 48.3mm OD (was 33.4mm OD). OD for 12 pipe size corrected to 323.9mm. Revision table now includes a list of latest changes. Details of bolting material added Table 1B /05/07 H DJH Pressure and temperature limits on use of and Figure 1 ASTM A106 Gr B clarified 08/10/09 I DJH 32NB valve now listed as a socket weld type. 08/10/09 I DJH Allowable pressures for carbon and stainless steel pipe added and and subsequent sections renumbered 08/10/09 I DJH Reference to SS150 added Introduction 08/10/09 I BC Material specification for stainless steel pipe and fittings added , 1.3.2, 1.5.2, /10/09 I DJH Tables of ANSI B pipes and 1.1 dimensions and weights moved to section /03/13 J RWT Wording of introduction modified Introduction 18/03/13 J RWT Reference to updated specs added to section /03/13 J RWT Nominal pipe sizes corrected in tables in and sections and /03/13 J RWT Distance between branches updated and /03/13 J RWT Wording of section modified to add where practical 18/03/13 J RWT Guidance on Vilter compressor oil feed pipework added 18/03/13 J RWT Reference to updated specs added to section /03/13 J RWT Clarification of paint colours for A106 pipe and A333 pipe 18/03/13 J RWT Reference to alternative welding codes 2.2 added 18/03/13 J RWT Reference to SS150 and SS156 added /03/13 J RWT Reference to alternative NDT specifications added 18/03/13 J RWT Note added concerning RFF valves /03/13 J RWT Requirement added that all stop valves are capped 18/03/13 J RWT Refrigeration controls section completely removed 18/03/13 J RWT Figure 2 removed Figure 2 10/03/14 K RWT Example stab in branch detail added /03/14 K RWT Note added covering DIN piping /03/14 K RWT Bolting section re-written for clarification /03/14 K RWT Reference to application standard ISO 5817 added for stainless steel & L:\Standard Specifications\SS024.K.Steel Piping.doc Page 15 of 16

16 SS 24 FIGURE 1 Material selection for welded pipework WELDING BS2633 CLASS 1 Pressure Bar G PIPE: ASTM A333 Gr6 FITTINGS: ASTM A420 Gr.WPL 6 FLANGES SOCKETS: ASTM A350 LF PIPE: ASTM A106 GrB ERW AP15L FITTINGS: ASTM A234 WPB FLANGES SOCKETS: ASTM A105 WELDING BS2971 CLASS II Low temp references ANSI B31.5 para PD5500 Appendix.D Temperature C REFRIGERATION Star Standard Specification No. 24 L:\Standard Specifications\SS024.K.Steel Piping.doc Page 16 of 16