ASTM A335 Grade P9 Alloy Steel Seamless Pipe Chrome Moly Pipe for High-Temperature Service

ASTM A335 / ASME SA335 Grade P9 Cr-Mo Alloy Steel Seamless Pipe Black Painted
 

ASTM A335 Grade P9 / UNS K90941 is a seamless 9Cr-1Mo chrome-moly alloy steel pipe for high-temperature service. It is used in boiler superheater/reheater piping, steam lines, headers, and refinery/power-plant piping. It offers good oxidation resistance and moderate high-temperature strength, but it is less common than P11, P22, and P91. For boiler tubes, the equivalent tube specification is usually ASTM A213 T9. Always verify the latest ASTM A335/A335M or ASME SA335 requirements and the specific purchase-order requirements before ordering or fabricating.

Note: For boiler tubes, the common matching grade is ASTM A213 T9.
A335 P9 is generally pipe for high-temperature piping systems; A213 T9 is tube for boilers, superheaters, and heat exchangers. Chemistry is similar, but the product specification and testing differ.

Equivalent Material ​of ASTM A335/ASME SA335 Grade P9 Alloy Steel Seamless Pipe

Chemical composition(%) of ASTM A335/ASME SA335 Grade P9 Alloy Steel Seamless Pipe

Mechanical Property of ASTM A335/ASME SA335 Grade P9 Alloy Steel Seamless Pipe

Application

1. Boiler superheater and reheater piping

2. Main steam piping and steam headers

3. High-temperature power-plant piping

4. Refinery and petrochemical high-temperature piping

5. Heat exchanger and heat-transfer piping in some services

6. Furnace and high-temperature process equipment

7. Hydrogen service where 9Cr-1Mo is suitable

For boiler tubes specifically, the matching tube grade is usually ASTM A213 T9.