Hot Products
- Carbon & Carbon Alloy Steel
- Stainless Steel
- Copper & Nickel Alloy
- Heat Efficiency Tubes
- Pipe Fittings
- Pipe Flanges
- Gasket, Stud Bolt &Nut
- Industrial Valves
0102030405
High-Temperature Seamless Ferritic Alloy-Steel Pipe Suppliers and Factory in China - ASTM A335/A335M
Ordering Information
Purchasers must specify the following when ordering:
- Quantity (length or number of pipes)
- Material grade (e.g., P11, P22, P91)
- Size (NPS or DN and schedule or wall thickness)
- Length (random or specific)
- ASTM designation (A335 or A335M for metric units)
- Optional requirements (e.g., additional testing, special finishes)
- Any supplementary requirements (S1–S7)
Material and Manufacture
- Process: Pipes shall be made by seamless process (hot-worked or cold-worked followed by heat treatment).
- Heat Treatment: All pipes must undergo proper heat treatment (e.g., normalization, tempering) to meet mechanical properties.
Chemical Composition
Each grade has specific limits for carbon, manganese, phosphorus, sulfur, silicon, chromium, molybdenum, and other alloying elements.
Mechanical Properties
- Tensile Strength, Yield Strength, and Elongation: Requirements vary by grade (e.g., P91: min. tensile strength 585 MPa, yield strength 415 MPa).
- Hardness Testing: Optional unless specified.
Test Requirements
- Hydrostatic Testing: Each pipe must withstand a specified hydrostatic pressure without leakage.
- Nondestructive Electric Testing (NDE): Optional unless required (e.g., eddy current, ultrasonic testing).
- Flattening Test, Bend Test, or Flange Test: Required for certain sizes and grades.
- Impact Testing: Required if specified (e.g., for low-temperature service).
Inspection & Certification
- Manufacturer must perform tests and provide a Certificate of Compliance.
- Third-party inspection may be required if specified in the purchase order.
Marking
Each pipe must be marked with:
- Manufacturer's name or trademark
- ASTM designation (A335 or A335M)
- Grade (e.g., P11, P22)
- Heat number
- Size and schedule
Supplementary Requirements
Optional additional tests (e.g., grain size analysis, special NDE methods) may be specified.
Keywords
Seamless pipe Alloy steel High-temperature service Ferritic steel P-grade steels
Main Grades in ASTM A335/A335M
| Grade | UNS Number | Key Alloy Composition | Common Applications |
|---|---|---|---|
| P1 | K11522 | 0.5Mo | Low-alloy boilers, piping |
| P2 | K11547 | 0.5Cr-0.5Mo | Power plants, refineries |
| P5 | K41545 | 5Cr-0.5Mo | High-temp/pressure service |
| P9 | S50400 | 9Cr-1Mo | Petrochemical, boilers |
| P11 | K11597 | 1.25Cr-0.5Mo-Si | Power generation, steam lines |
| P12 | K11562 | 1Cr-0.5Mo | Similar to P11, boilers |
| P21 | K31545 | 3Cr-1Mo | High-temp strength |
| P22 | K21590 | 2.25Cr-1Mo | Widely used in power plants |
| P91 | K91560 | 9Cr-1Mo-V-Nb | Advanced high-temp/pressure |
| P92 | K92460 | 9Cr-2W-0.5Mo-V-Nb | Ultra-supercritical boilers |
| P122 | K91640 | 11Cr-2W-1Cu-Mo-V-Nb | High-efficiency power plants |
⚙️ Key Notes:
• Grades P5 to P92 are chromium-molybdenum (Cr-Mo) steels, offering increasing resistance to oxidation and creep at elevated temperatures.
• P91, P92, and P122 are advanced high-strength steels used in modern power plants for ultra-supercritical (USC) applications.
• P1 and P2 are lower-alloy grades for less severe conditions.
These grades are selected based on temperature, pressure, and corrosion resistance requirements in industries like power generation, oil & gas, and petrochemical plants.
🔔 Want to order the same? Contact us Now to send your request!
❓ Frequently Asked Questions
What is ASTM A335/A335M and what is it used for?
ASTM A335/A335M is a standard specification covering seamless ferritic alloy-steel pipe intended for high-temperature service. It is widely used in power generation, oil & gas, and petrochemical industries where pipes must withstand elevated temperatures and pressures.
What grades are available under ASTM A335, and how do I choose the right one?
ASTM A335 includes grades such as P1, P2, P5, P9, P11, P12, P21, P22, P91, P92, and P122. Grade selection depends on operating temperature, pressure, and corrosion resistance requirements. For example, P91 and P92 are used in advanced ultra-supercritical (USC) power plants, while P11 and P22 are common in standard power generation applications.
What information is required when placing an order for ASTM A335 pipe?
When ordering, you must specify the quantity, material grade, pipe size (NPS or DN and schedule/wall thickness), length (random or specific), ASTM designation, any optional or supplementary requirements (S1–S7), and the applicable ASTM standard (A335 for inch units or A335M for metric units).
What testing and inspection is required for ASTM A335 pipes?
Each pipe must pass hydrostatic testing to verify pressure integrity. Additional tests such as nondestructive electric testing (NDE), flattening, bend, or flange tests may be required depending on size and grade. Impact testing is required for low-temperature service applications. The manufacturer must provide a Certificate of Compliance, and third-party inspection can be arranged if specified.
What are the key mechanical property requirements for ASTM A335 Grade P91?
For Grade P91, the minimum tensile strength is 585 MPa and the minimum yield strength is 415 MPa. Elongation requirements also apply and vary by pipe size. Hardness testing is optional unless specifically requested in the purchase order.
How are ASTM A335 pipes marked and identified?
Each pipe is required to be clearly marked with the manufacturer's name or trademark, the ASTM designation (A335 or A335M), the material grade (e.g., P11, P22), the heat number, and the pipe size and schedule. This ensures full traceability and compliance with the standard.