Astm A335 P91 Alloy Pipe
ASTM A335 P91 seamless ferritic alloy steel pipe for high-pressure boiler and elevated-temperature service. Designed for demanding applications requiring high creep strength, suitable for bending, flanging, forming operations, and fusion welding, with mandatory hydrostatic and non-destructive examination.
Standard & Grade
- Standard: ASTM A335 / ASTM A335M
- ASME Equivalent: SA335
- Grade: P91
- Product type: Seamless ferritic alloy steel pipe
Service & Applications
- High-pressure boiler piping
- High-temperature service applications
- Power generation and energy plants
- Petrochemical and refinery systems
Dimensions
- Outer Diameter (OD): 19.05 mm – 114.3 mm
- Wall Thickness: 2.0 mm – 14 mm
- Length: up to 16000 mm
Material & Manufacture
- Pipe may be supplied hot finished or cold drawn
- Manufactured by the seamless process
- Finishing heat treatment applied as specified
Heat Treatment Options
- A (Annealed) / N + T (Normalized & Tempered)
- N + T / Q + T (Quenched & Tempered)
- N + T (Normalized & Tempered)
Inspection & Testing
- Hydrostatic test applied to each length of pipe
- Non-destructive examination (NDE) as per required practices
- Chemical composition inspection
- Mechanical properties tests: tensile strength, yield strength, elongation
- Flattening test
- Hardness test or bend test
- Flaring, bending, and impact tests where specified
- Surface and dimensional inspection
Mechanical Test Sampling
- Batch-type furnace: tests on 5% of pipes from each treated lot (minimum one pipe)
- Continuous heat treatment: tests on 5% of the lot (minimum two pipes)
Surface Treatment
- Oil-dip
- Varnish
- Passivation
- Phosphating
- Shot blasting
Packing & Marking
- Bare packing, bundle packing, or crate packing
- Wooden protection at both ends of pipes
- Sea-worthy export packing as required
- Each crate marked with order number, heat number, dimensions, weight, and bundle details