ASTM A335 P22 Alloy Steel Seamless Pipe specification
Cr-Mo Alloy Steel P22 Seamless Pipes for High-Temperature Service | Technical Specification PDF Download
The ASTM A335 P22 Alloy Steel Seamless Pipe Specification PDF provides a comprehensive technical reference for chromium-molybdenum (Cr-Mo) alloy steel P22 seamless pipes used in high-temperature and high-pressure service. This specification covers chemical composition, mechanical properties, heat treatment requirements, manufacturing process, dimensions and tolerances, testing and inspection, and typical applications in power plants, refineries, and petrochemical facilities.
ASTM A335 Standard Overview:
ASTM A335 is the standard specification for seamless ferritic alloy steel pipes intended for high-temperature service. Pipes produced to ASTM A335 are widely used in pressure piping systems where strength, creep resistance, and long-term stability at elevated temperatures are required.
Grade P22 is one of the most commonly specified Cr-Mo alloy steel grades under ASTM A335, offering improved high-temperature strength compared to lower chromium grades such as P11.
Material Grade: ASTM A335 P22
-
Standard: ASTM A335 / ASME SA335
-
Grade: P22
-
Material Type: Ferritic Alloy Steel (Cr-Mo Steel)
-
Manufacturing Method: Seamless
-
Product Form: Steel Pipes
-
UNS Number: K21590
ASTM A335 P22 seamless pipes are widely used in high-temperature pressure piping systems due to their excellent creep resistance and oxidation resistance.
Chemical Composition (Typical, %)
| Grade | Carbon (%) | Manganese (%) | Phosphorus max (%) | Sulfur max (%) | Silicon max (%) | Chromium (%) | Molybdenum (%) |
| ASTM A335 P22 | 0.05 – 0.15 | 0.30 – 0.60 | 0.025 | 0.025 | 0.50 | 1.90 – 2.60 | 0.87 – 1.13 |
Chemical composition limits are defined by ASTM A335 for Grade P22.
Mechanical Properties (Minimum Requirements)
| Property | Longitudinal | Transverse |
| Tensile strength, min (MPa) | 415 | |
| Yield strength, min (MPa) | 205 | |
| Elongation ≥8 mm thickness (%) | 30 | 20 |
| Elongation, 4D specimen (%) | 22 | 14 |
| Deduction per 0.8 mm thickness reduction (%) | 1.50 | 1.00 |
Heat Treatment
ASTM A335 P22 seamless pipes are typically supplied in one of the following heat treatment conditions:
-
Normalized and tempered
Proper heat treatment is essential to achieve the required mechanical properties and long-term performance in high-temperature service.
Manufacturing Process
ASTM A335 P22 alloy steel seamless pipes are manufactured by:
-
Hot rolling or hot extrusion
-
Heat treatment in accordance with ASTM A335 requirements
-
Straightening and sizing
-
Final inspection and testing
The seamless construction eliminates weld seams and improves reliability in high-pressure applications.
Dimensions & Tolerances
ASTM A335 P22 pipes are generally ordered by NPS (Nominal Pipe Size) and Schedule (wall thickness).
Key dimensional controls include:
-
Outside Diameter (OD) tolerance
-
Minimum wall thickness requirement (commonly based on 87.5% rule)
-
Ovality and straightness
-
Length: random length, double random length, or fixed cut length
General dimensional requirements are typically governed by ASTM A999 / A999M unless otherwise specified.
Testing & Inspection
Each ASTM A335 P22 seamless pipe may be subjected to:
-
Chemical analysis
-
Tensile testing
-
Hardness testing
-
Hydrostatic testing or non-destructive testing (UT / ET)
-
Dimensional and visual inspection
Mill Test Certificates (EN 10204 3.1) are normally supplied.
Applications
-
Power Plant Boilers
-
Superheaters & Reheaters
-
High-Temperature Steam Lines
-
Oil Refineries
-
Petrochemical Processing Units
-
Pressure Piping Systems
ASTM A335 P22 seamless pipes are widely used in high-temperature and pressure service environments.
Download ASTM A335 P22 Alloy Steel Seamless Pipe Specification PDF
Download the complete ASTM A335 P22 Alloy Steel Seamless Pipe Specification PDF, including chemical composition limits, mechanical requirements, heat treatment conditions, and testing procedures.
👉 Download astm_a335_p22_alloy_steel_seamless_pipe_specification
👉 Download ASTM A335 Standard Specification PDF