Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.

Buttweld Fittings

ASTM A234 WP22 Fittings

2.25% Chromium – 1% Molybdenum alloy steel buttweld fittings with high creep strength for main steam, hot reheat and hydroprocessing service.

ASTM A234 / ASME SA234 1/2" – 24" NB IBR Approved
2.25Cr-1Mo Grade

ASTM A234 WP22 Alloy Steel Buttweld Fittings

Tubewell Steel & Engg. Co. manufactures, stocks and supplies ASTM A234 WP22 fittings from Mumbai, India. With 2.25% chromium and 1% molybdenum, WP22 offers higher creep-rupture strength than WP11 and is the matching fitting grade for A335 P22 pipe in power, refinery and hydrogen service.

StandardASTM A234 / ASME SA234
GradeWP22 Cl.1 / Cl.3 (UNS K21590)
Size Range1/2" NB – 24" NB
ScheduleSCH 10 – SCH XXS

Product Overview

Higher creep strength for main steam and hydrogen service

ASTM A234 WP22 is a wrought ferritic alloy steel fitting grade with 1.90–2.60% chromium and 0.87–1.13% molybdenum. Doubling the molybdenum content compared with WP11 gives WP22 noticeably better creep and stress-rupture strength, while the higher chromium improves resistance to oxidation and high-temperature hydrogen attack. WP22 is therefore widely specified for main steam and hot reheat lines in thermal power plants and for hydrotreater and hydrocracker piping in refineries.

WP22 is offered in Class 1 (415 MPa min tensile) and Class 3 (485 MPa min tensile). We supply seamless and welded (WPW22) elbows, tees, reducers, caps and stub ends to ASME B16.9 / B16.28, annealed or normalized and tempered, bevelled to ASME B16.25 and marked per MSS SP-25. Every lot ships with EN 10204 3.1 certificates, with IBR documentation and third-party inspection available on request.

  • Higher creep strength than WP11
  • Resistant to high-temperature hydrogen attack
  • Matches A335 P22 pipe and A182 F22
  • Class 1 and Class 3 available
  • IBR approved supply available
  • 100% PMI and heat traceability

Specifications

Standard supply range for ASTM A234 WP22 fittings

ParameterDetails
StandardASTM A234, ASME SA234
GradeWP22 Class 1, WP22 Class 3 (UNS K21590); WPW22 for welded
Dimension StandardASME B16.9, ASME B16.28, MSS SP-43
Size (NB)Seamless: 1/2" NB to 24" NB; Welded: 2" NB to 48" NB
Wall ThicknessSCH 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS
Elbows45°, 90° and 180° – Long Radius (1.5D) and Short Radius (1D)
Bending RadiusR = 1D, 1.5D, 2D, 3D, 5D and custom pipe bends
Tees & CrossesEqual Tee, Reducing Tee, Equal Cross, Reducing Cross
ReducersConcentric Reducer, Eccentric Reducer
Other TypesPipe Cap, Stub End (Long / Short pattern), Return Bend
ManufacturingSeamless (WP) and Welded (WPW) – hot formed / cold formed
Heat TreatmentFull / Isothermal Annealed or Normalized & Tempered
EndsBevelled Ends as per ASME B16.25
CertificatesEN 10204 3.1 / 3.2, IBR, NACE MR0175, TPI Reports

Material Grades & Equivalents

International equivalents of A234 WP22

GradeASTM / ASMEUNSENW.Nr.JISMatching Pipe / Forging
WP22A234 / SA234 WP22K2159010CrMo9-101.7380STPA 24A335 P22 / A182 F22

Chemical Composition

Weight %, as per ASTM A234

CCarbon0.05–0.15
MnManganese0.30–0.60
PPhosphorus≤ 0.040
SSulphur≤ 0.040
SiSilicon≤ 0.50
CrChromium1.90–2.60
MoMolybdenum0.87–1.13
GradeCMnPSSiCrMo
WP22 Cl.1 / Cl.30.05 – 0.150.30 – 0.600.040 max0.040 max0.50 max1.90 – 2.600.87 – 1.13

Mechanical Properties

Values at room temperature as per ASTM A234

GradeTensile StrengthYield Strength (min)Elongation (Long.)Elongation (Trans.)Hardness (max)
WP22 Cl.1415 – 585 MPa (60 – 85 ksi)205 MPa (30 ksi)30%20%197 HB
WP22 Cl.3485 – 655 MPa (70 – 95 ksi)275 MPa (40 ksi)22%14%197 HB
415MPa
Min. Tensile Strength (Cl.1)
205MPa
Min. Yield Strength (Cl.1)
30%
Min. Elongation (Cl.1)

Physical Properties

Typical values (for reference)

PropertyMetricImperial
Density7.80 g/cm³0.282 lb/in³
Melting Range1450 – 1510 °C2640 – 2750 °F
Modulus of Elasticity205 GPa29.7 × 10³ ksi
Thermal Conductivity (100°C)36 W/m·K20.8 BTU/h·ft·°F
Mean Thermal Expansion (20–300°C)12.6 µm/m·°C7.0 µin/in·°F
Specific Heat0.46 J/g·°C0.11 BTU/lb·°F
Max. Service Temperature≈ 600 °C≈ 1110 °F

Dimension Chart

As per ASME B16.9 – center-to-end / end-to-end dimensions in mm

Showing standard sizes. Other sizes available on request.
NPSOD at Bevel90° LR Elbow (A)45° LR Elbow (B)Tee (C / M)180° LR Return (O)Cap (E)Reducer (H)
1/2"21.33816257625–
3/4"26.7381929762538
1"33.4382238763851
1 1/4"42.2482548953851
1 1/2"48.35729571143864
2"60.37635641523876
2 1/2"73.09544761903889
3"88.911451862295189
4"114.31526410530564102
5"141.31907912438176127
6"168.32299514345789140
8"219.1305127178610102152
10"273.1381159216762127178
12"323.9457190254914152203
14"355.65332222791067165330
16"406.46102543051219178356
18"457.06862863431372203381
20"508.07623183811524229508
22"559.0838343419–254508
24"610.09143814321829267508

All dimensions in mm. A, B, C/M = center-to-end; O = center-to-center; E = cap length (for standard wall); H = reducer end-to-end. Wall thickness is matched to the specified pipe schedule.

Applications

Where ASTM A234 WP22 fittings are used

Main Steam Lines

Main steam and hot reheat piping in subcritical power stations.

Hydroprocessing

Hydrotreater and hydrocracker reactor piping in hydrogen service.

Refineries

Reformer, heater outlet and high-pressure process lines.

Boilers & HRSG

Superheater headers and high-pressure HRSG piping.

Fertilizer Plants

Ammonia synthesis loops and hot hydrogen lines.

Petrochemicals

Cracker and reactor effluent piping at elevated temperature.

Testing & Why Choose Us

Quality you can verify on every heat

Ready Stock

Large inventory for fast dispatch

Certified Material

MTC EN 10204 3.1 / 3.2

100% PMI

Positive material identification

On-time Delivery

Pan-India & export shipping

Radiography Test Ultrasonic Test Dye Penetrant Test Magnetic Particle Test Hardness Test Tensile Test Macro / Micro Test Dimensional Inspection

Frequently Asked Questions

Quick answers about A234 WP22 fittings

WP22 contains 1.90–2.60% chromium and 0.87–1.13% molybdenum, with 0.05–0.15% carbon and silicon limited to 0.50% max. It is the fitting equivalent of A335 P22 pipe and A182 F22 forgings.

WP22 has roughly double the chromium and molybdenum of WP11, which gives it higher creep-rupture strength and better hydrogen-attack resistance at elevated temperature. WP11 remains a cost-effective choice for moderate temperatures.

They are strength classes with identical chemistry. Class 1 requires 415–585 MPa tensile and 205 MPa minimum yield; Class 3 requires 485–655 MPa tensile and 275 MPa minimum yield. Class 3 is often specified to match P22 pipe strength.

WP22 is an ASME P-No. 5A material. Preheat of around 150–200°C and PWHT typically in the 705–760°C range are specified by ASME B31.1 / B31.3, depending on wall thickness and service.

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