Alloy Steel P91 Seamless Pipe ASTM A335 / ASME SA335 Gr P91 IBR

Product Description

ASTM A335 P91 Alloy Steel Seamless Pipe

ASTM A335 / ASME SA335 Grade P91 is seamless ferritic alloy-steel pipe for high-temperature service. P91 is a 9Cr-1Mo steel modified with vanadium, niobium and nitrogen (9Cr-1Mo-V-Nb). A335 covers nominal wall and minimum wall pipe suitable for bending, flanging and fusion welding. SA-335 is the designation referenced in ASME pressure codes. The pipe is normalized and tempered (or quenched and tempered): normalize at 1040-1080 C, temper at 730-800 C.

Grade, Types and Equivalents

P91 is ordered as Type 1 or Type 2. Type 2 has tighter residual-element limits than Type 1, so please state the type in your enquiry.

• UNS: K91560
• EN 10216-2 / DIN: X10CrMoVNb9-1 / 1.4903
• GB 5310: 10Cr9Mo1VNbN
• Matching forms (separate products): A234 WP91 fittings, A182 F91 flanges/forgings, A387 Gr 91 plate, A213 T91 tube

Chemical composition, P91 Type 1 (%)

Maximum: P 0.020, S 0.010, Ni 0.40, Al 0.02, Ti 0.01, Zr 0.01.

Mechanical properties: tensile strength 585 MPa (85 ksi) min, yield strength 415 MPa (60 ksi) min, elongation 20% min longitudinal (50 mm gauge), hardness 190-250 HB.

Sizes and Dimensions

Dimensions are to ASME B36.10M. The usual range is NPS 1/2 inch to 24 inch (OD 21.3 mm to 610 mm) in Sch 10, 20, 30, 40, STD, 60, 80, XS, 100, 120, 140, 160 and XXS. For example, 6 inch NB (168.3 mm OD) is 7.11 mm wall and 28.26 kg/m in Sch 40, and 10.97 mm wall and 42.56 kg/m in Sch 80. Common lengths are 6 m, 12 m or cut lengths. Ends are plain or bevelled (37.5 degrees, for butt welding). Finish is mill finish with dark grey oxide scale, uncoated. A size table with wall thickness and weight per metre is in the listing images. Please share NB, schedule and quantity for availability.

Standards and Tests

• ASTM A335/A335M (active edition A335/A335M-26) and ASME SA-335/SA-335M
• Dimensions: ASME B36.10M
• Tests required by A335: hydrostatic test on each length, nondestructive examination of each pipe, tension test, flattening test, hardness or bend test, chemical analysis
• Supplementary requirements S1-S9, PMI, UT and third-party inspection when ordered
• The usual supply basis is an EN 10204 type 3.1 mill test certificate. Type 3.2 adds endorsement by the purchaser's representative or an inspector designated by official regulations.

Applications and Industries

• Main steam pipes, headers and reheat pipes in thermal power boilers
• Main steam and hot reheat lines in supercritical and ultra-supercritical boilers
• HRSG main steam piping and superheater headers
• High-temperature power and process piping
• Industries: power generation, petrochemical, oil refining

Supply from Allied Metal & Tubes

Allied Metal & Tubes, Khetwadi, Mumbai, Maharashtra, established 1993, are stockists and dealers of stainless steel pipes, tubes, sheets and plates, carbon steel seamless pipes, alloy steel pipes and other ferrous and non-ferrous metals. We are ISO 9001:2015 certified and MSME registered, and supply buyers across India. For this range, we can supply IBR-certified pipe (Indian Boiler Regulations, Form III-A) on request.

FAQ

Can you supply P91 pipe with IBR Form III-A?
Yes. IBR-certified pipe with Form III-A can be supplied for this range on request.

Should I order Type 1 or Type 2?
Both are A335 P91 designations. Type 2 has tighter residual-element limits. Order the type your specification or drawing calls for.

What is the UNS number and EN equivalent of P91?
UNS K91560. The EN 10216-2 counterpart is X10CrMoVNb9-1 (1.4903).

Which test certificate comes with the pipe?
Usually an EN 10204 3.1 mill test certificate. PMI, UT and third-party inspection must be ordered separately.