ASTM A234 WPB Carbon Steel Pipe Fittings
ASTM A234 Grade WPB — the world's most widely specified carbon steel buttweld fitting grade. Used in oil & gas, power generation, water treatment, petrochemical and general industrial piping systems operating from -29°C to 427°C. ASME B16.9 (buttweld) and EN 10253-2 Type B. IBR/CCOE approved for Indian boiler & pressure vessel service. EN 10204 3.1/3.2. Sizes ½″ to 72″.
½″–72″
Largest Range
427°C
Max Service Temp
415 MPa
Min Tensile
IBR/CCOE
Approved
Request WPB Quote
Response within 1 business day
Grade Equivalents
WPB is derived from A105 (forged) or A106 Gr.B (pipe) — the fitting inherits the base material properties. For EN 10253-2 European projects, material is often dual-certified ASTM/EN.
| ASTM | EN (nearest) | JIS | BS | ASME P-No. |
|---|---|---|---|---|
| A234 WPB (fittings) | P235GH / 1.0345, P265GH / 1.0425 | STPT42, STPT410 | Grade 360 | 1, Gr 1 |
| A106 Gr.B (pipe) | P265GH / 1.0425 | STPT410 | — | 1 |
| A105 (forgings) | P250GH / 1.0460 | S25C | — | 1 |
| A53 Gr.B (pipe) | — | — | — | 1 |
Chemical Composition
| Standard | C | Mn | Si | P | S | Cr+Mo+Ni (max) |
|---|---|---|---|---|---|---|
| ASTM A234 WPB | ≤0.30 | 0.29–1.06 | ≥0.10 | ≤0.050 | ≤0.058 | 1.00 (combined) |
| EN 1.0425 (P265GH) | ≤0.20 | 0.80–1.40 | ≤0.40 | ≤0.025 | ≤0.010 | — |
WPB has wider carbon range than modern EN grades — dual certification to EN 10253-2 requires tighter heat analysis control. Specify "Dual Cert ASTM/EN" in your RFQ if required for European PED projects.
Mechanical Properties
| Standard | Min. UTS (MPa) | Min. YS (MPa) | Elongation (%) | Max. Hardness | Temp Range |
|---|---|---|---|---|---|
| ASTM A234 WPB | 415 | 240 | ≥22% | — | -29°C to 427°C |
| EN 1.0425 P265GH | 410–570 | ≥265 | ≥21% | — | -20°C to 400°C |
For lower temperature service (below -29°C), specify WPL6 (A234 WPL6) or carbon steel to EN 10216-2 P265GH with Charpy impact testing.
Welding & PWHT Guidance
Welding: WPB is readily weldable
WPB requires no preheat for wall thickness ≤25 mm under normal conditions. For wall thickness >25 mm, preheat to 80–150°C is recommended to avoid hydrogen-induced cracking. Recommended filler metals: ER70S-6 (GTAW/TIG) or E7018 (SMAW/MMA).
Preheat (t ≤25 mm)
Not required for ambient temperature conditions. Preheat to 80°C where hydrogen risk is elevated (low hydrogen process preferred).
Preheat (t >25 mm)
80–150°C minimum. Use low-hydrogen electrodes. Pre-dry E7018 rods at 350°C/1 hr before use.
Filler Metal
ER70S-6 (GTAW) or E7018 (SMAW). Match strength to base metal — both exceed 415 MPa UTS.
PWHT Requirement
Per ASME B31.3, PWHT is generally required for P-No. 1 when wall thickness exceeds 19 mm (¾ inch), or as required by the applicable code. PWHT temperature: 595–650°C.
ASME Classification
P-No. 1, Group 1. Compatible with a wide range of WPS qualifications for carbon steel.
IBR/CCOE Note
IBR/CCOE (Indian Boiler Regulations) requires material test certificates endorsed by an Inspecting Authority. We supply WPB with IBR certification as standard for Indian projects.
Typical Applications
Oil & Gas Pipelines
Onshore and offshore gathering lines, trunk lines and process pipelines within the -29°C to 427°C operating envelope.
Power Generation
Steam and condensate systems, cooling water, auxiliary piping in thermal, combined-cycle and biomass power plants.
Petrochemical Process
Refinery process lines, heat exchanger headers, utility steam, low-temperature process service.
Water Treatment & Utility
Potable and process water mains, sewage treatment, desalination plant utility piping.
HVAC & Building Services
Heating and chilled water distribution, district heating networks, commercial HVAC plant rooms.
General Industrial Piping
Compressed air, steam, hydraulic and general fluid service piping across all industrial sectors.
WPB vs WPC vs WPL6 — Grade Comparison
| Grade | UTS min | Low-Temp Rating | Notes |
|---|---|---|---|
| WPB | 415 MPa | -29°C | Standard grade, most widely used. General piping service. |
| WPC | 485 MPa | -29°C | Higher strength, tighter carbon control. For higher pressure ratings. |
| WPL6 | 415 MPa | -46°C | Low-temperature with Charpy impact testing. Sub-arctic and LTCS service. |
WPB covers the vast majority of carbon steel fitting requirements in oil & gas, power and general piping.
Available Fitting Types — ASTM A234 WPB
Elbows
45°, 90° and 180° long radius (LR) and short radius (SR). ASME B16.9 / EN 10253-2 Type B.
Sizes: ½″–72″ | SCH: 5S to XXS
Equal & Reducing Tees
Straight and reducing tees. ASME B16.9 / EN 10253-2 Type B. Available in all schedules.
Sizes: ½″–72″
Concentric & Eccentric Reducers
Concentric and eccentric reducing patterns. ASME B16.9 / EN 10253-2 Type B.
Sizes: ¾″×½″ to 72″×60″
Pipe Caps
Dished end caps for line termination. ASME B16.9 / EN 10253-2.
Sizes: ½″–72″
Laterals & Crosses
45° laterals and four-way crosses. ASME B16.9.
Sizes: ½″–24″ standard; larger on request
Stub Ends (Lap Joint)
Type A and Type B stub ends for use with lap joint flanges. ASME B16.9 / MSS SP-43.
Sizes: ½″–72″
Weld Neck Flanges
ASME B16.5 (Classes 150–2500) and ASME B16.47 Series A/B (NPS 26″–60″).
Material: A105 / A694
Slip-On, Blind & Socket Weld Flanges
Full range of flange types to ASME B16.5. RTJ and raised face facing available.
Classes 150–2500
Large Bore Fittings
Elbows, tees and reducers in NPS 24″–72″. Fabricated from plate or pipe per ASME B16.9 and MSS SP-75.
IBR approval available on request
Ready to order ASTM A234 WPB fittings?
Specify size, schedule, fitting type, standard (ASME B16.9 or EN 10253-2 Type B), and required MTR. IBR/CCOE available as standard. We respond within 1 business day.
Request a Quote →