BUTT WELD FITTINGS MATERIALS

The most common material grades for butt weld fittings are:

Carbon steel / alloy steel fittings

  • ASTM A234 (specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service
    • ASTM A 234 WPB / WPC (carbon steel) - ASTM A 234 WP1 / WP5 / WP9 / WP12 / WP22 / WP91 / WP92 (alloy steel)
  • ASTM A860 (specification for high yield wrought carbon steel fittings)
    • ASTM A850 WPHY 42 to WPHY70
  • ASTM A420 Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Low-Temperature Service
    • ASTM A 420 WPL3 / WPL6

Stainless steel fittings

  • ASTM A403 Specification for Wrought Austenitic Stainless Steel Piping Fittings (TP 304 to TP 347) 
  • ASTM A790 UNS S31803 S32205 (duplex wrought fittings) / ASTM A 790 UNS S32750 S32760 (superduplex butt weld fittings)

Nickel alloy fittings

  • B366 Specification for Factory-Made Wrought Nickel and Nickel Alloy Fittings (Inconel, Incoloy, Hastelloy, ...)

Aluminium and aluminium alloy pipe fittings

  • B361 Specification for Factory-Made Wrought Aluminum and Aluminum-Alloy Welding Fittings
     

ASTM A234 BUTTWELD FITTINGS (CARBON STEEL FITTINGS)

Composition, %
Grade C Mn P max S max Si Cr Mo Ni Cu Others
WPB
(1,2,3,4,5)
0.30
max
0.29-1.06 0.050 0.058 0.10
min
0.40
max
0.15
max
0.40
max
0.40
max
V 0.08
max
WPC
(2,3,4,5)
0.35
max
0.29-1.06 0.050 0.058 0.10
min
0.40
max
0.15
max
0.40
max
0.40
max
V 0.08
max
WP1 0.28
max
0.30-0.90 0.045 0.045 0.10-0.50   0.44-0.65      
WP12 CL1 0.05-
0.20
0.30-0.80 0.045 0.045 0.60
max
0.80-1.25 0.44-0.65      
WP12 CL2 0.05-
0.20
0.30-0.80 0.045 0.045 0.60
max
0.80-1.25 0.44-0.65      
WP11 CL1 0.05-
0.15
0.30-0.60 0.030 0.030 0.50-1.00 1.00-1.50 0.44-0.65      
WP11 CL2 0.05-
0.20
0.30-0.80 0.040 0.040 0.50-1.00 1.00-1.50 0.44-0.65      
WP11 CL3 0.05-
0.20
0.30-0.80 0.040 0.040 0.50-1.00 1.00-1.50 0.44-0.65      
WP22 CL1 0.05-
0.15
0.30-0.60 0.040 0.040 0.50
max
1.90-2.60 0.87-1.13      
WP22 CL3 0.05-
0.15
0.30-0.60 0.040 0.040 0.50
max
1.90-2.60 0.87-1.13      
WP5 CL1 0.15
max
0.30-0.60 0.040 0.030 0.50
max
4.0-6.0 0.44-0.65      
WP5 CL3 0.15
max
0.30-0.60 0.040 0.030 0.50
max
4.0-6.0 0.44-0.65      
WP9 CL1 0.15
max
0.30-0.60 0.030 0.030 1.00
max
8.0-10.0 0.90-1.10      
WP9 CL3 0.15
max
0.30-0.60 0.030 0.030 1.00
max
8.0-10.0 0.90-1.10      
WPR 0.20
max
0.40-1.06 0.045 0.050       1.60-
2.24
0.75-1.25  
WP91 0.08-
0.12
0.30-0.60 0.020 0.010 0.20-0.50 8.0-9.5 0.85-1.05 0.40
max
  V 0.18- 0.25
Nb 0.06-0.10
N 0.03-0.07
Al 0.02 max(6)
Ti 0.01 max(6)
Zr 0.01 max(6)
WP911 0.09-
0.13
0.30-0.60 0.020 0.010 0.10-0.50 8.0-9.5 0.90-1.10 0.40
max
  V 0.18-0.25
Nb 0.060-0.10
N 0.04-0.09
Al 0.02 max(6)
B 0.0003-0.006
W 0.90-1.10
Ti 0.01 max(6)
Zr 0.01 max(6)

Notes:

  1. Fittings from bar or plate 0.35 max carbon.
  2. Fittings from forgings 0.35 max Carbon and 0.35 max Silicon with no minimum.
  3. For each reduction of 0.01% below the specified Carbon maximum, an increase of 0.06% Manganese above the specified maximum is permitted, up to a maximum of 1.35%.
  4. The sum of Cu, Ni, Niobium, and Moly shall not exceed 1.00%.
  5. The sum of Niobium and Moly shall not exceed 0.32%.
  6. Applies to heat and product analyses.

 

ASTM A234 (source: ASME)

This specification covers wrought carbon steel and alloy steel fittings of seamless and welded construction. These fittings are for use in pressure piping and in pressure vessel fabrication for service at moderate and elevated temperatures. The material for fittings shall consist of killed steel, forgings, bars, plates, seamless or fusion-welded tubular products with filler metal added. Forging or shaping operations may be performed by hammering, pressing, piercing, 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 imperfections in the fittings. Fittings, after forming at an elevated temperature, shall be cooled to a temperature below the critical range under suitable conditions to prevent injurious defects caused by too rapid cooling, but in no case more rapidly than the cooling rate in still air. The fittings shall be subjected to tension test, hardness test, and hydrostatic test. This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification covers wrought carbon steel and alloy steel fittings of seamless and welded construction covered by the latest revision of ASME B16.9, B16.11, MSS-SP-79, MSS-SP-83, MSS-SP-95, and MSS-SP-97. These fittings are for use in pressure piping and in pressure vessel fabrication for service at moderate and elevated temperatures. Fittings differing from these ASME and MSS standards shall be furnished in accordance with Supplementary Requirement S58 of Specification A960/A960M.

1.2 Optional supplementary requirements are provided for fittings where a greater degree of examination is desired. When desired, one or more of these supplementary requirements may be specified in the order.

1.3 This specification does not cover cast welding fittings or fittings machined from castings. Cast steel welding fittings are governed by Specifications A216/A216M and A217/A217M.

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 units), 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 other. Combining values from the two systems may result in non-conformance with the standard.

 

ASTM A403 BUTTWELD FITTINGS (STAINLESS STEEL FITTINGS)

Composition, %
Grade UNS
nbsp;
C
strong>(1)
Mn
strong>(1)
P
strong>(1)
S
strong>(1)
Si
strong>(1)
Ni Cr Mo Ti N
strong>(2)
Others
WPXM-19 S20910 0.06 4.0-6.0 0.045 0.030 1.0 11.5-13.5 20.5-23.5 1.50-3.0   0.20-0.40 (3)
WP304 S3040 0.08 2.0 0.045 0.030 1.0 8.0-11.0 18.0-20.0        
WP304L S30403 0.030
(4)
2.0 0.045 0.030 1.0 8.0-12.0 18.0-20.0        
WP304H S30409 0.04-0.10 2.0 0.045 0.030 1.0 8.0-11.0 18.0-20.0        
WP304N S30451 0.08 2.0 0.045 0.030 1.0 8.0-11.0 18.0-20.0     0.10-0.16  
WP304LN S30453 0.030 2.0 0.045 0.030 1.0 8.0-11.0 18.0-20.0     0.10-0.16  
WP309 S3090 0.20 2.0 0.045 0.030 1.0 12.0-15.0 22.0-24.0        
WP310S S3108 0.08 2.0 0.045 0.030 1.0 19.0-22.0 24.0-26.0        
WPS31254 S31254 0.020 1.0 0.030 0.010 0.80 17.5-18.5 19.5-20.5 6.0-6.5   0.18-0.22 Cu0.50-1.0
WP316 S3160 0.08 2.0 0.045 0.030 1.0 10.0-14.0 16.0-18.0 2.0-3.0      
WP316L S31603 0.030 align="center"(4) 2.0 0.045 0.030 1.0 10.0-14.0
(5)
16.0-18.0 2.0-3.0      
WP316H S31609 0.04-0.10 2.0 0.045 0.030 1.0 10.0-14.0 16.0-18.0 2.0-3.0   0.10-0.16  
WP316N S31651 0.08 2.0 0.045 0.030 1.0 10.0-13.0 16.0-18.0 2.0-3.0   0.10-0.16  
WP316LN S31653 0.030 2.0 0.045 0.030 1.0 10.0-13.0 16.0-18.0 2.0-3.0   0.10-0.16  
WP317 S3170 0.08 2.0 0.045 0.030 1.0 11.0-15.0 18.0-20.0 3.0-4.0      
WP317L S31703 0.030 2.0 0.045 0.030 1.0 11.0-15.0 18.0-20.0 3.0-4.0      
WPS31725 S31725 0.030 2.0 0.045 0.030 1.0 13.5-17.5 18.0-20.0 4.0-5.0   0.20  
WPS31726 S31726 0.030 2.0 0.045 0.030 1.0 13.5-17.5 17.0-20.0 4.0-5.0   0.10-0.20  
WPS31727 S31727 0.030 1.0 0.030 0.030 1.0 14.5-16.5 17.5-19.0 3.8-4.5   0.15-0.21 Cu2.8-4.0
WPS32053 S32053 0.030 1.0 0.030 0.010 1.0 24.0-26.0 22.0-24.0 5.0-6.0   0.17-0.22  
WP321 S3210 0.08 2.0 0.045 0.030 1.0 9.0-12.0 17.0-19.0   (6)    
WP321H S32109 0.04-0.10 2.0 0.045 0.030 1.0 9.0-12.0 17.0-19.0   (7)    
WPS33228 S33228 0.04-0.08 1.0 0.020 0.015 0.30 31.0-33.0 26.0-28.0       Ce 0.05-0.10 Al 0.025Nb 0.6-0.10
WPS34565 S34565 0.030 5.0-
7.0
0.030 0.010 1.0 16.0-18.0 23.0-25.0 4.0-5.0   0.40-0.60 Nb 0.10
WP347 S3470 0.08 2.0 0.045 0.030 1.0 9.0-12.0 17.0-19.0       (8)
WP347H S34709 0.04-0.10 2.0 0.045 0.030 1.0 9.0-12.0 17.0-19.0       (9)
WP348 S3480 0.08 2.0 0.045 0.030 1.0 9.0-12.0 17.0-19.0       Nb+Ta= 103(C)-1.10Ta 0.10Co 0.20
WP348H S34809 0.04-0.10 2.0 0.045 0.030 1.0 9.0-12.0 17.0-19.0       Nb+Ta= 83(C)-1.10Ta 0.10Co 0.20
WPS38815 S38815 0.030 2.0 0.040 0.020 5.5-
6.5
13.0-17.0 13.0-15.0 0.75-1.50     Cu 0.75-1.50Al 0.30

Notes:

  1. Maximum, if not otherwise indicated.
  2. The method of analysis for Nitrogen is agreed between the purchaser and manufacturer.
  3. Niobium 0.10-0.30%; Vanadium, 0.10-0.30%.
  4. For small diameter or thin walls a Carbon maximum of 0.040% is mandatory in grades TP304L and TP316L. Small outside diameter tubes are those less than 0.50 in. [12.7 mm] 5) in outside diameter and light wall tubes as those less than 0.049 in. [1.24 mm] in average wall thickness.
  5. On pierced tubing, the Nickel may be 11.0-16.0%.
  6. 5 X (C+N2)-0.70.
  7. 4 X (C+N2) -0.70.
  8. The Niobium % shall be ten times above the Carbon content and not more than 1.10%.
  9. The Niobium % shall be eight times above the Carbon content and not more than 1.10%.

 

ASTM A403 (source: ASME

This specification covers the standard for wrought austenitic stainless steel fittings for pressure piping applications. The material for fittings shall consist of forgings, bars, plates, or seamless or welded tubular products. Forging or shaping operations shall be performed by hammering, pressing, piercing, extruding, upsetting, rolling, bending, fusion welding, machining, or by a combination of two or more of these operations. All fittings shall undergo heat-treatment. Chemical and product analyses shall be performed and shall conform to the required chemical composition in carbon, manganese, phosphorus, sulfur, silicon, chromium, molybdenum, and titanium. Tension test shall be done on the fitting material to determine the tensile properties such as yield strength and tensile strength. Fittings supplied under this specification shall be examined visually for surface discontinuities, surface checks, and mechanical marks. This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification covers wrought stainless steel fittings for pressure piping applications.2

1.2 Several grades of austenitic stainless steel alloys are included in this specification Grades are designated with a prefix, WP or CR, based on the applicable ASME or MSS dimensional and rating standards, 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 nondestructive test method and extent of nondestructive examination (NDE). Table 1 is a general summary of the fitting classes applicable to all WP grades of stainless steel covered by this specification. There are no classes for the CR grades. Specific requirements 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 units), 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 other. Combining values from 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.

 

ASTM vs EN STEEL FITTINGS MATERIALS

Carbon steel fittings
Material number EN GRADES FOR PIPE FITTINGS ASTM GRADES FOR PIPE FITTINGS
1.0254 St 37.0 S235 -
- - - -
1.0305 St 35.8/I P235GH (1.0345) A 234 Grade WPA
1.0305 St 35.8/III P235GH (1.0345) -
1.0405 St 45.8/I P265GH (1.0425) A 234 Grade WPB
1.0405 St 45.8/III P265GH (1.0425) -
Alloy fittings
1.5415 15 Mo 3 16Mo3 A 234 Grade WP1
1.7335 13 CrMo 4 4 13CrMo4-5 A 234 Grade WP11, WP12
1.7380 10 CrMo 9 10 10CrMo9-10 A 234 Grade WP22
1.7362 12 CrMo 19 5 X11CrMo5 A 234 Grade WP5
- - - A 234 Grade WP9
1.4903  - X10CrMoVNb9-1 A 234 Grade WP91
Low temperature fittings
1.5637 10 Ni 14 12Ni14 A 420 Grade WPL3
1.0356 TTSt 35 N P215NL (1.0451) -
1.0356 TTSt 35 V - -
- - - A 420 Grade WPL6
High yield fittings
- - - -
1.0486 StE 285 - A 860 Grade WPHY42
1.0562 StE 355 P355N A 860 Grade WPHY52
1.8902 StE 420 - A 860 Grade WPHY60
1.8905 StE 460 - A 860 Grade WPHY70
High yield steels
1.0457 StE 240.7 - -
1.0484 StE 290.7 L290NB A 860 Grade WPHY42
1.0582 StE 360.7 L360NB A 860 Grade WPHY52
1.8972 StE 415.7 L415NB A 860 Grade WPHY60
- - - -
Stainless steel fittings
1.4541 X 6 CrNiTi 18 10 X6CrNiTi18-10 A 403 Grade WP321
1.4571 X 6 CrNiMoTi 17 12 2 X6CrNiMoTi17-12-2 A 403 Grade WP316Ti
1.4301 X 5 CrNi 18 10 X5CrNi18-10 A 403 Grade WP304
1.4306 X 2 CrNi 19 11 X2CrNi19-11 A 403 Grade WP304L
1.4307  - X2CrNi18-9 A 403 Grade WP304L
1.4401 X 5 CrNiMo 17 12 2 X5CrNiMo17-12-2 A 403 Grade WP316
1.4404 X 2 CrNiMo 17 13 2 X2CrNiMo17-12-2 A 403 Grade WP316L
1.4462 X 2 CrNiMoN 22 5 3 X2CrNiMoN22-5-3 UNS S 31803 (Duplex)
1.4529 X 1 NiCrMoCuN 25 20 6 X1NiCrMoCuN25-20-7 UNS N 08926
1.4539 X 1 NiCrMoCuN 25 20 5 X1NiCrMoCu25-20-5 UNS N 08904 (904L)
1.4547  - X1CrNiMoCuN20-18-7 UNS S 31254

 

 

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