Seamless
ASTM A335 Alloy Steel Pipe
ASTM A335 seamless ferritic alloy-steel pipe for high-temperature service — P5, P9, P11, P22, P91 grades for power plants, refineries, and petrochemical facilities.
ASTM A335 alloy steel pipe
OVERVIEW
The chrome-moly standard for high-temperature piping.
ASTM A335 covers seamless ferritic alloy-steel pipe for high-temperature service in power plants, refineries, and petrochemical facilities. The specification spans grades from P5 (5Cr-0.5Mo) through P91 (9Cr-1Mo-V), each engineered for a specific temperature-pressure-corrosion envelope.
Global Seamless manufactures A335 pipe in all standard grades with in-house normalizing, tempering, and quench-and-temper heat treatment. Every pipe ships with documented heat treatment parameters, full mechanical properties, and Mill Test Certificates to EN 10204 3.1 or 3.2.
✓ Grades: P5, P9, P11, P12, P22, P91
✓ Sizes: NPS 1/2″ through NPS 24″
✓ Schedules: Std through XXS and custom wall
✓ N+T and Q+T heat treatment in-house
✓ IBR and PED certified
ASTM A335 chrome-moly pipe
DIMENSIONAL SPECIFICATIONS
Available size range.
Cold Drawn Seamless (CDS)
| Grade | Composition | Max Service Temp | Min Yield, psi (MPa) |
|---|---|---|---|
| P5 | 5Cr-0.5Mo | ~1,090°F (590°C) | 30,000 (205) |
| P9 | 9Cr-1Mo | ~1,100°F (595°C) | 30,000 (205) |
| P11 | 1.25Cr-0.5Mo | ~1,000°F (540°C) | 30,000 (205) |
| P22 | 2.25Cr-1Mo | ~1,080°F (580°C) | 30,000 (205) |
| P91 | 9Cr-1Mo-V | ~1,150°F (620°C) | 60,000 (415) |
APPLICATIONS & INDUSTRIES
Where these tubes get used.
MATERIAL GRADES
Chrome-moly grades for every temperature.
LOW ALLOY
P11 · P12
1-1.25Cr grades for subcritical steam piping up to 1,000°F (540°C).
MEDIUM ALLOY
P22 · P5 · P9
2.25-9Cr grades for elevated temperature and sulfidation resistance.
TECHNICAL ARTICLES
Latest insights on alloy steel pipe.
ARTICLE
P11 vs P22 Chrome-Moly Selection
Comparing 1Cr and 2.25Cr for your temperature range.
ARTICLE
P91 T91 Supercritical Applications
Advanced 9Cr-1Mo-V for next-generation power plants.
ARTICLE
Heat Treatment of Alloy Steel
Normalizing, tempering, and Q&T for chrome-moly grades.
RELATED PRODUCTS
Often paired with.
RELATED
Stainless Steel Seamless
TP304/316 for corrosion-resistant elevated temperature service.
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