What is ASTM A234 WPB?
ASTM A234 is the material specification for wrought carbon and alloy steel piping fittings for moderate and elevated-temperature service. Grade WPB is the carbon steel workhorse of the specification and the most commonly ordered buttweld fitting grade worldwide.
Key Takeaways
- ASTM A234 WPB scope: Elbows, tees, reducers, caps, stub ends and returns, seamless or welded, with the dimensional geometry taken from ASME B16.9 and the material requirements from A234.
- Size range: NPS 1/2 inch to 48 inch, in schedules from SCH 10 to SCH XXS.
- Ratings: Rated by matching pipe schedule rather than by flange class.
- Material grades: WPB carbon steel; WP11, WP22 and WP91 chrome-moly for elevated temperature; WP304 / WP316 under the companion A403 specification for stainless.
- Kalp Alloys manufactures to ASTM A234 WPB in Ahmedabad, India, with EN 10204 3.1 and 3.2 certification issued in its own name.
- Third-party inspection by SGS, BV, TUV or Lloyds can be witnessed at our plant before dispatch.
What ASTM A234 WPB governs
ASTM A234 is the material specification for wrought carbon and alloy steel piping fittings for moderate and elevated-temperature service. Grade WPB is the carbon steel workhorse of the specification and the most commonly ordered buttweld fitting grade worldwide.
Elbows, tees, reducers, caps, stub ends and returns, seamless or welded, with the dimensional geometry taken from ASME B16.9 and the material requirements from A234.
Scope, sizes and ratings at a glance
The envelope below is the practical reference: what to state on a purchase order so the item that arrives is the item the line needs.
| Parameter | Detail |
|---|---|
| Size range | NPS 1/2 inch to 48 inch, in schedules from SCH 10 to SCH XXS |
| Ratings | Rated by matching pipe schedule rather than by flange class |
| Material grades | WPB carbon steel; WP11, WP22 and WP91 chrome-moly for elevated temperature; WP304 / WP316 under the companion A403 specification for stainless |
| Dimensional standard | ASME B16.9 |
| Grade WPB | Carbon steel, general service |
| Grade WP11 / WP22 | Chrome-moly, elevated temperature |
| Grade WP91 | Modified 9Cr-1Mo, high-temperature power service |
| Stainless equivalent | ASTM A403 WP304 / WP316 |
| Rated by | Matching pipe schedule, not flange class |
| Elbow radii | 1.5D long radius standard; 1D short radius on request |
The point buyers most often get wrong
A234 WPB fittings are rated by wall thickness, not by a pressure class. A fitting is specified to match the schedule of the pipe it joins, so a SCH 40 elbow belongs on SCH 40 pipe. Ordering by nominal size alone without stating the schedule is the most frequent cause of a fitting arriving with a wall that does not match the run, which then forces either a transition weld or a rejection.
What Kalp Alloys manufactures to ASTM A234 WPB
Kalp Alloys is a manufacturer, not a stockist. Production runs at our own facility at 5, Jay Vijay Industrial Estate, B/h. Akash Vikas Estate, Keval Kanta Road, Rakhial, Ahmedabad, which means the heat number stamped on the part traces to our own melt record and the mill test certificate is issued in the name of Kalp Alloys.
That matters on standard-led purchasing more than anywhere else, because an approved-vendor submission or a code-governed line has to show who made the part. A certificate passed down a trading chain names a mill the buyer has no relationship with and cannot query.
Grades supplied against ASTM A234 WPB cover WPB carbon steel; WP11, WP22 and WP91 chrome-moly for elevated temperature; WP304 / WP316 under the companion A403 specification for stainless. Non-standard bores, thicknesses, drilling patterns and facing finishes are produced to customer drawing.
Ordering against ASTM A234 WPB
State the dimensional standard, the size or NPS range, the rating or schedule, the facing where applicable, the material specification and grade, the quantity, and the certification level required. A quotation is typically returned within 24 hours.
Drawings for non-standard items can be sent by email or on WhatsApp at +91 81608 73937 and are reviewed by the technical team. Stock sizes dispatch in three to seven days; made-to-drawing items carry a firm lead time quoted at order confirmation. There is no minimum order on stock sizes and trial quantities are accepted.
Frequently Asked Questions
ASTM A234 is the material specification for wrought carbon and alloy steel piping fittings for moderate and elevated-temperature service. Grade WPB is the carbon steel workhorse of the specification and the most commonly ordered buttweld fitting grade worldwide.
NPS 1/2 inch to 48 inch, in schedules from SCH 10 to SCH XXS. Ratings covered are Rated by matching pipe schedule rather than by flange class.
WPB carbon steel; WP11, WP22 and WP91 chrome-moly for elevated temperature; WP304 / WP316 under the companion A403 specification for stainless.
WP denotes a wrought piping fitting and B is the carbon steel grade designation within ASTM A234. WP11, WP22 and WP91 are the chrome-moly grades in the same specification.
A long radius elbow has a centreline radius of 1.5 times the nominal diameter and is the default because it produces less pressure drop. A short radius elbow at 1.0 times the diameter is used only where space forces it.
Yes. Kalp Alloys manufactures to ASTM A234 WPB at its own facility at 5, Jay Vijay Industrial Estate, B/h. Akash Vikas Estate, Keval Kanta Road, Rakhial, Ahmedabad, and issues the EN 10204 3.1 or 3.2 mill test certificate in its own name rather than passing through a third-party mill certificate.
An EN 10204 3.1 mill test certificate as standard, stating the ordered standard, grade and heat number, with chemical and mechanical results and a dimensional inspection report. EN 10204 3.2 with third-party inspection by SGS, BV, TUV or Lloyds is arranged where the project requires it.