Alloy Steel · Fittings · ASTM A234 WP91
ASTM A234 WP91 Fittings
In short: ASTM A234 WP91 fittings (elbows, tees, reducers) complete P91 steam piping, supplied normalised and tempered to match the pipe.
- P91
- Designation
- 7.77
- density, g/cm³
- 3.1 / 3.2
- EN 10204 certificates
- 5
- P91 product forms
Why this combination
Why P91 in fittings
Fittings in P91 lines must receive the same heat treatment as the pipe; a wrongly tempered elbow is a weak point.
Hardness and PMI checks apply to fittings as to pipe.
Specification
How to specify ASTM A234 WP91
Butt-weld ½" – 48" (larger fabricated to order) in schedules matching the pipe; socket-weld and threaded ⅛" – 4" in Class 2000, 3000, 6000 and 9000
- Specification
- ASTM A234 WP91
- Butt-weld
- A234 WP91, ASME B16.9
Sizes and weights
ASTM A234 WP91 sizes, weighed at 7.77 g/cm³
Other sizes on request. For general fittings information, such as manufacturing routes and end finishes, see the fittings guide.
Butt-weld ½" – 48" (larger fabricated to order) in schedules matching the pipe; socket-weld and threaded ⅛" – 4" in Class 2000, 3000, 6000 and 9000
Chemistry
P91 composition
- Density
- 7.77 g/cm³
| Element | Limit, % | Why it matters |
|---|---|---|
| C | 0.08 – 0.12 | |
| Mn | 0.30 – 0.60 | |
| P | 0.020 max | |
| S | 0.010 max | |
| Si | 0.20 – 0.50 | |
| Cr | 8.00 – 9.50 | |
| Mo | 0.85 – 1.05 | |
| V | 0.18 – 0.25 | |
| Nb | 0.06 – 0.10 | |
| N | 0.030 – 0.070 | |
| Ni | 0.40 max | |
| Al | 0.02 max |
Limits per ASTM A335 (P91); other product forms and specifications differ slightly. Your order's specification and edition govern.
Questions
About ASTM A234 WP91
Do WP91 fittings need hardness testing?
It is widely specified to confirm correct heat treatment.
Seamless or welded WP91?
Per your piping class; seamless is common in smaller sizes.
From enquiry to dispatch
How a ASTM A234 WP91 order runs
- 01 EnquiryGrade, specification, size, quantity
- 02 ReviewChecked against your standard
- 03 InspectPMI, dimensions, TPI if required
- 04 CertifyEN 10204 3.1 / 3.2, heat traceable
- 05 ShipPacked and documented for the destination
Need ASTM A234 WP91?
Send size, quantity, specification and destination. We reply with availability, certificates and delivery.