BUTT WELD FITTINGS MATERIALS


Butt weld fittings are manufactured from seamless or welded pipes or steel plates. In this article, we give an overview of the most common ASTM materials for carbon, alloy, stainless and nickel-alloy butt weld fittings.


BW FITTINGS MATERIAL GRADES

The most common material grades for butt weld fittings are:

CARBON AND ALLOY STEEL FITTINGS MATERIALS

  • ASTM A234 WPA/WPB/WPC (carbon steel for high-temperature service) to match ASTM A53, ASTM A106 and API 5L Gr. B pipes
  • ASTM A420 WPL3/WPL6 the (carbon steel for low-temperature service) to match ASTM A333 Gr.3 and ASTM A333 Gr. 6 pipes
  • ASTM A 234 WP1/WP5/WP9/WP12/WP22/WP91/WP92 (alloy steel fittings, WP91 is a common grade for power generation) to match ASTM A335 chrome-moly pipes
  • ASTM A860 WPHY52/WPHY60 (the specification for high yield wrought carbon steel fittings) to match high yield API 5L pipes from Gr. X52 to X60 and above

carbon steel fittings

STAINLESS AND NICKEL-ALLOY STEEL FITTINGS MATERIALS

  • ASTM A403 WP304/WP316/WP321 etc. (austenitic steel fittings) to match ASTM A312 TP304/TP316/TP321, etc., pipes
  • ASTM A815 UNS S31803 (duplex steel fittings) and UNS S32750/UNS S32760 (super duplex fittings) to match ASTM A790 and ASTM A928 pipes
  • ASTM B366 Specification for Factory-Made Wrought Nickel and Nickel Alloy Fittings (Inconel, Incoloy, Hastelloy, …)

stainless steel fittings

Aluminum and aluminum-alloy butt weld fittings

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


ASTM A234 FITTINGS MATERIAL (CARBON/ALLOY STEEL)

ASTM A234 CHEMICAL COMPOSITION

ASTM A234 Grade for Butt Weld Fittings: Chemical 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 MECHANICAL PROPERTIES

TENSILE AND YIELD STRENGTH

CARBON & ALLOY BW FITTINGS

WPB WPC,
WP11-CL2
WP11-CL1,
WP22-CL1
WP5-CL1
WP9-CL1
WP11-CL3,
WP22-CL3
WP5-CL3
WP9-CL3
WP91
Tensile strength, minimum unless a range is given ksi (MPa) 60 (415) 70 (485) 60 (415) 75 (520) 90 (620)
Yield strength, min ksi (MPa) (0.2% offset or 0.5% extension under-load) 35 (240) 40 (275) 30 (205) 45 (310) 60 (415)

ELONGATION OF  CARBON & ALLOY BW FITTINGS

WPB,
WPC, WP11, WP22
WP91
  Longitud. Transverse Longitud. Transverse
Standard
round specimen, or small proportional specimen, min % in 4 D
22 14 20 13
Rectangular specimen for wall thickness 5/16″ and over, and
for all small sizes tested in full section; min % in 2 in.
30 20
Rectangular specimen for wall thickness less than 5/16″;
min % in 2 in (1/2″ wide specimen)
see note

Note:  For each 0.79 mm decrease in wall thickness below 7.94 mm, a deduction of 1.5 % for longitudinal and 1.0 % for transverse from standard values is permitted


ASTM A403 FITTINGS MATERIAL (STAINLESS STEEL)

ASTM A403 CHEMICAL COMPOSITION

ASTM A403 Butt Weld Fittings. Chemical 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 MECHANICAL PROPERTIES

Tensile and Elongation Requirements WP304, WP316 WP304L, WP316L
Yield Strength, min, ksi [MPa] 30 [205] 25 [170]
Tensile Strength, min, ksi [MPa] 75 [515] 70 [485]
Elongation Longitudinal 28 28
Transverse 20 20

 


 

ASTM A815 FITTINGS MATERIALS (DUPLEX/SUPER DUPLEX)

ASTM A815 CHEMICAL COMPOSITION

DUPLEX FITTINGS CHEMICAL COMPOSITION (UNS S31803/UNS S32205)

Grade C Mn Si P S Cr Mo Ni N Fe
S31803 0.030 max 2.00 max 1.00 max 0.030 max 0.020 max 22.0 – 23.0 3.0 – 3.5 4.50 – 6.50 0.14 – 0.20 63.72 min
S32205 0.030 max 2.00 max 1.00 max 0.030 max 0.020 max 21.0 – 23.0 2.50 – 3.50 4.50 – 6.50 0.8 – 0.20 63.54 min

DUPLEX FITTINGS MECHANICAL PROPERTIES (UNS S31803/UNS S32205)

Grades Density (g/cm 3) Density (lb/in 3) Melting Point (°C) Melting Point (°F)
S31803 / S32205 7.805 0.285 1420 – 1465 2588 – 2669

 

SUPER DUPLEX FITTINGS CHEMICAL COMPOSITION (UNS S32750/UNS S32760)

Grade C Mn Si P S Cr Mo Ni N Fe
S 32750 0.030 max 1.20 max 0.80 max 0.035 max 0.020 max 24.00 – 26.00 3.00 – 5.00 6.00 – 8.00 0.24 – 0.32 58.095 min
S 32760 0.05 max 1.00 max 1.00 max 0.030 max 0.010 max 24.00 – 26.00 3.00 – 4.00 6.00 – 8.00 0.20 – 0.30 57.61 min

SUPER DUPLEX FITTINGS MECHANICAL PROPERTIES  (UNS S32750/UNS S32760)

Grades Density (g/cm 3) Density (lb/in 3) Melting Point (°C) Melting Point (°F)
S32750 / S32760 7.8 0.281 1350 2460

 


EUROPEAN AND ASTM MATERIALS FOR FITTINGS

Butt Weld Fittings Materials Comparison Chart
Werkstoff Number European Grade ASTM Grade
CARBON STEEL FITTINGS MATERIALS
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 STEEL FITTINGS MATERIALS
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 CARBON STEEL FITTINGS MATERIALS
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 CARBON STEEL FITTINGS MATERIALS
– –
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 CARBON STEEL FITTINGS MATERIALS
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 MATERIALS
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