ASTM A403 WP304L Wrought Austenitic Stainless Steel Piping Fittings
1. Scope :
1.1 This specification covers wrought stainless steel fittings for pressure piping applications .
1.2 Several grade of austenitic stainless steel alloy are included in this specification grades are designated with a prefix , WP or CR , based on the applicable ASME or MSS dimensional and rating standard , respectively .
1.3 For each of the WP stainless grades , several classes of fittings are covered , to indicate whether seamless or welded construction was utilized . Class designations are also utilized to indicate the non-destructive test method and extent of non-destructive examination (NDE) . Table 1 is a general summary of the fitting classes applicable to all WP grade of stainless steel covered by this specification . There are covered elsewhere .
1.4 This specification is expressed in both inch-pound units and in SI units . However, unless the order specifies the applicable “M” specification designation (SI uints), the material shall be furnished to inch-pound units .
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard . Within the text , the SI units are shown in brackets . The values stated in each system may not be exact equivalents ; therefore , each system shall be used independently of the order . Combining values form the two systems may result in non-conformance with the standard .
1.6 This specification does not apply to cast steel fittings . Austenitic stainless steel castings are covered in specifications A351/A351M , A743/A743M , and A744/A744M .
2. Referenced Documents
2.1 ASTM Standards :
A351/A351M Specification for castings , Austenitic , for Pressure-Containing Parts
A370 Test Method and Definitions for Mechanical Testing of Steel Products
A743/A743M Specifications of Castings , Iron-Chromium , Iron-Chromium-Nickel , Corrosion resistant . for General Application
A744/A744M Specifications of Castings , Iron-Chromium-Nickel , corrosion Resistant , for server service
A751 Test Methods , Practices , and terminology for Chemical Analysis of steel Products
A960/A960M Specification for Common Requirements for Wrought Steel piping fittings E112 Test Method for Determining Average Grain Size
E165 Practice for Liquid Penetrant Examination for general Industry
2.2 ASME Standards :
ASME B16.9 Factory-Made Wrought Steel Butt-Welding Fittings
2.3 MSS Standards :
MSS-SP-25 Standard Marking System for Valves,fittings,flanges,and Unions
MSS-SP-79 Socket-Welding Reducer Inserts
2.4 ASME Boiler and Pressure Vessel Code :
Section VIII Division I , Pressure Vessels Section IX , Welding Qualifications
2.5 AWS Standards :
5.4 Specification for Corrosion – Resisting Chromium and Chromium-Nickel Steel Covered Welding Electrodes A 5.9 Specification for Corrosion – Resisting Chromium and Chromium-Nickel Steel Welding Rods and Bare Electrodes A 5.11 Specification for Nickel and Nickel – Alloy Welding Electrodes for Shielded Metal Arc Welding 2.6 ASNT: SNT-TC-1A (1984) Recommended Practice for Nondestructive Testing Personnel Qualification and Certification 3. Common Requirements and Ordering Information :
TABLE 1 Fitting Classes for WP Grades
|Seamless||Radiography or Ultrasonic||WU|
ate degassing and refining optional) ,
4.2.2 Vacuum furnace , or 4.2.3 One of the former followed by vacuum or electroslagconsumable remelting .
4.3 If secondary melting is employed , the heat shall be defined as all ingots remelted from a primary heat .
5. Manufacture :
5.1 Forming – Forging or shaping operations may be performed by hammering , pressing , extruding , upsetting , rolling , bending , fusion welding , machining , or by a combination of two or more of these operations . The forming procedure shall be so applied that it will not produce injurious defects in the fittings .
5.2 All fittings shall be heat treated in accordance with Section 6 .
5.3 Grade WP fittings ordered as Class S shall be of seamless construction and shall meet all requirements of ASME B 16.9 , ASME B 16.11 , MSS SP-79 , MSS SP-83 , MSS SP-95 , or MSS SP-97 .
5.4 Grade WP fittings ordered as Class shall meet the requirements of ASME B16.9 and :
5.4.1 Shall have all pipe welds made by mill or the fittings manufacture with the addition of filler metal radiographically examined throughout the entire length in accordance with the Code requirements stated in 5.5 .
5.4.2 Radiographic inspection is not required on single longitudinal seam welds made by the starting pipe manufacture if made without the addition of filler metal. ;
5.4.3 Radiographic inspection is not required on longitudinal seam fusion welds made by the fitting manufacturer when all of the following conditions have been met :
188.8.131.52 no addition of filler metal ,
184.108.40.206 Only one welding pass per weld seam , and ,
220.127.116.11 Fusion welding from one side only .
5.4.4 In place of radiographic examination , welds made by the fitting manufacturer may be ultrasonically examined in accordance with the code requirements stated in 5.6 .
5.5 Grade WP fittings ordered as Class WX shall meet the requirements of ASME B16.9 and shall have all welds , whether made by the fitting manufacture or the starting materials manufacturer , radiographically examined throughout their entire length in accordance with Paragraph UW-51 of Section VIII , Division I , of the ASME Boiler and Pressure Vessel Code .
5.6 Grade WP fitting ordered as Class WU shall meet the requirements of ASME B16.9 and shall have all welds , whether made by the fittings manufacture or the starting material manufacturer , ultrasonically examined throughout their entire length in accordance with appendix 12 of Section VIII , Division I , of ASME Boiler and Pressure Vessel Code .
5.7 The radiography or ultrasonic examination of welds for this class of fittings may be done at the option of the manufacturer , either prior to or after forming
5.8 Personnel performing NDE examinations shall be qualified in accordance with SNT-TC-1A .
5.9 Grade CR fittings shall meet the requirements of MSS SP-43 and do not require non-destructive examination .
5.10 All fitting shall have the welders , welding operators , and welding procedures qualified under the provisions of Section IX of the ASME Boiler and Pressure Vessel Code except that starting pipe welds made without the addition of filler metal do not require such qualification .
5.11 ALL joints welded with filler metal shall be finished in accordance with the requirements of Paragraph UW-35(a) Of Section VIII , Division I , Of the ASME Boiler and Pressure Vessel Code .
5.12 Fittings machined from bar shall be restricted to NPS or smaller . Elbows , return bends , tees , and header tees shall not be machined directly from bar stock .
5.12.1 All caps machined from bar shall be examined by liquid penetrant in accordance with Supplementary Requirements S52 in Specification A960/A960M.
5.13 Weld build up is permitted to dimensionally correct unfilled areas produced during cold forming of stub ends . Radiographic examination of the weld buildup shall not be required provided that all the following steps are adhered to : 5.13.1 The weld procedure and welders or welding operators meet the requirements of 5.10 .
5.13.2 Annealing is performed after welding and prior to machining . 5.13.3 All weld surface are liquid penetrant examined in accordance with Appendix 8 of Section VIII , Division 1 of the ASME Boiler and Pressure Vessel Code .
5.13.4 Repair of areas in the weld is permitted , but 5.13.1 , 5.13.2 , and 5.13.3 must be repeated .
5.14 Stub ends may be produced with the entire lap added as weld metal to a straight pipe section provided the welding satisfies the requirements of 5.10 for qualifications and Section 6 for post weld heat treatment.
5.14.1 Grade WP Class WX – Radiographic inspection of the weld is required . See 5.4 .
5.14.2 Grade WP Class WX – Radiographic inspection of all welds is required See 5.5 .
5.14.3 Grade WP Class WU – Ultrasonic inspection of all welds required . See 5.6 .
5.14.4 Grade CR – non-destructive examination is not required . See 5.12.1 .
5.15 Stub ends may be produced with the entire lap added by the welding of a ring , made from plate or bar of the same alloy grade and composition , to the outside of straight section of pipe , provided the weld is double welded , is a full penetration joint , satisfies the requirements of 5.10 for qualifications and Section 6 for post weld heat treatment .
5.15.1 Grade WP Class W – Radiographic inspection of the welds , made with the addition of filler metal , is required (see 5.4) .
5.15.2 Grade WP Class WX – Radiographic inspection of all welds , made with or without the addition of filler metal , is required (see 5.5) .
5.15.3 Grade WP Class WU – Radiographic inspection of all welds , made with or without the addition of filler metal , is required (see 5.6) .
5.15.4 Grade CR non0destructive examination is not required (see 5.9) . 5.16 After final heat treatment , all “H-Grade” steel fittings shall have a grain size of 7 or coarser in accordance with Test Methods E112 .
TABLE 2 Chemical Requirements
|Grade WP||Grade CR||UNS||Cᴮ||Mnᴮ||Pᴮ||Sᴮ||Siᴮ||Ni||Cr||Mo||Ti||N2Cᶜ|
|WP 304||CR 304||S 30400||0.08||2||0.045||0.03||1||8.0-11.0||18.0-20.0|
|WP 304L||CR 304L||S 30403||0.03||2||0.045||0.03||1||8.0-12.0||18.0-20.0|
|WP 304H||CR 304H||S 30409||0.04-0.10||2||0.045||0.03||1||8.0-11.0||18.0-20.0|
|WP 304N||CR 304N||S 30451||0.08||2||0.045||0.03||1||8.0-11.0||18.0-20.0||….||….||0.10-0.16|
|WP 304LN||CR 304LN||S 30453||0.03||2||0.045||0.03||1||8.0-11.0||18.0-20.0||…..||….||0.10-0.16|
|WP 316||CR 316||S 31600||0.08||2||0.045||0.03||1||10.0-14.0||16.0-18.0||2.00-3.00|
|WP 316L||CR 316L||S 31603||0.03||2||0.045||0.03||1||10.0-14.0||16.0-18.0||2.00-3.00|
|WP 316H||CR 316H||S 31609||0.04-0.10||2||0.045||0.03||1||10.0-14.0||16.0-18.0||2.00-3.00|
|WP 316N||CR 316N||S 31651||0.08||2||0.045||0.03||1||10.0-13.0||16.0-18.0||2.00-3.00||….||0.10-0.16|
|WP 316LN||CR 316LN||S 31653||0.03||2||0.045||0.03||1||10.0-13.0||16.0-18.0||2.00-3.00||…||0.10-0.16|
|WP 321||CR 321||S 32100||0.08||2||0.045||0.03||1||9.0-12.0||17.0-19.0||…||G||…|
|WP 321H||CR 321H||S 32109||0.04-0.10||2||0.045||0.03||1||9.0-12.0||17.0-19.0||….||H||….|
6. Heat Treatment :
6.1 All fittings shall be furnished in the heat – treatment condition . For H grades , separate solution heat treatments are required for solution annealing ; in-process heat treatments are not permitted as a substitute for the separate solution annealing treatments . The heat – treat procedure , except for those grades listed in 6.2 , shall consist of solution annealing the fitting at the temperatures listed for each grade in Table 4 units the chromium carbides go into solution , and then cooling at a sufficient rate to prevent reprecipitation .
6.2 A solution annealing temperature above 1950 °F [1065 °C] may impair the resistance to intergranular corrosion after subsequent exposure to sensitizing conditions in 321 , 321H , 347 , and 347H . When specified by the purchaser a lower temperature stabilization or resolution anneal shall be used subsequent to the initial high temperature solution anneal (see supplementary requirements S2) .
6.3 All welding shall be done prior to heat treatment .
6.4 Fittings machined directly from solution – annealed forgings and bar stock need not be resolution annealed .
7. Chemical Composition :
7.1 The chemical composition of each cast or heat used shall be determined and shall conform to the requirements of the chemical composition for the respective grades of material listed in Table 2 . The ranges as shown have been expanded to include variations of the chemical analysis requirements that are listed in the various specifications for starting materials (pipe , tube , plate , bar , and forgings) normally used in the manufacturing of fittings to this specification . Methods and practices relating to chemical analyses required by this specification shall be in accordance with Test Methods , Practices , and Terminology A751 . Product analysis tolerances in accordance with Specification A960/A960M are applicable .
7.2 The steel shall not contain any unspecified elements for the ordered grade to the extent that it conforms to the requirements of another grade for which that element is a specified elements having a required minimum content .
7.3 In fittings of welded construction , the alloy content (carbon , chromium , nickel , molybdenum , columbium , and tantalum) of the deposited weld metal shall conform to that required of the base metal or for equivalent weld metal as given in the AWS filler metal specification A 5.4 or A 5.9 (Type 348 weld metal is listed in AWS A 5.9 but not in AWS A5.4) . Exceptions are when welding on Types 304L and 304 base metals , the deposited weld metal shall correspond , respectively , to AWS E308L(ER308L) and E308 (ER304) , when welding on Type 321 base metal , the weld metal shall correspond to AWS Type E347 n(ER347 or ER321) ; and when welding on S31725 , S31726 , S31254 or S33228 deposited weld metal shall correspond either to the alloy content of the base metal or to AWS A 5.11 E NiCrMo. 3 (UNS W86112) (AWS A5.14 Ni Cr Mo. 3 (UNS N06625)) . On S38815 base metals , the deposited weld metal and filler metalused shall be agreed upon between purchaser and manufacturer .
7.3.1 Supplementary Requirements SI may be specification may be specified where 16-8-2 filler metal is required for joining thick section of Types 316 , 321 , or 347 and has adequate corrosion resistance for the intended service .
8. Tensile Properties :
8.1 The tensile properties of the fitting material shall conform to the requirements of table 5 . The testing and reporting shall be performed in accordance with Test Methods and Definitions A370 .
8.1.1 specimens cut either longitudinally or transversely shall be acceptable for the tensile test . 8.1.2 While Table 5 specifies elongation requirements for both longitudinal and transverse specimens it is not the intent that both requirements apply simultaneously . Instead , it is intended that only the elongation requirement that is appropriate for the specimens used be applicable .
8.2 Records of the tension test made on the starting material shallbe certification that the material of the fitting meets the requirements of this specification provided that heat treatments are the same .
8.3 If the raw material was not tested , or if the heat treatment of the raw material was different than the heat treatment of the fitting , the fitting manufacturer shall perform at least one tension test per heat on material representative of the fitting , and in the same condition of heat treatment as the fitting it repre
sents . qualification of welding procedures shall be in accordance with 5.8 .
8.4 If a tension test through the weld is desired , Supplementary Requirement S51 in Specification A960/A960M should be specified .
TABLE 6 Product Marking Examples for Grades and Classes
|Grade and Class Marking||Description|
|CR304||Singe grade : No classes in CR grade|
|CR304/304L||Multiple grades , meet chemical and mechanical properties of each|
|WP304-S||Single grade : seamless|
|WP304-W||Single Grade ; welded : RT or UT pipe welds with filler metal and all fitting manufacture´s welds|
|WP304-WX||Single grade: welded : RT all welds with or without filler metal|
|WP304-WU||Single grade ; welded : UT all welds with or without filler metal|
|WP304-304L-S||Multiple grades : meet chemical and mechanical properties of each : seamless|