What Is The Difference Between T91 And P91 Steel Pipes

T91 and P91 steel pipes are heat resistance alloy steel pipes with 9Cr1MoVNb chemistry, specially designed for high-temperature service. They share nearly identical chemical composition but differ in executive standard, the control of trace elements, mechanical properties, and application fields.

 

Grade T91 and Grade P91 share nearly chemical composition but differ in the control of trace elements. Grade T91 strictly control the aluminum content below 0.02%, to reduce the adverse effects on high-temperature toughness. While grade P91 optimized its nitrogen content (within 0.03%-0.07%) to enhance its strength. On the term of executive standard, Grade T91 is belong to ASTM A213 standard, while grade P91 is belong to ASTM A335 standard.

Grade T91 and grade P91 steel pipes have different application fields. 

Grade T91 steel pipe is suitable for small diameter, precision tube applications in high-temperature systems:

a. Boiler superheater and reheater tubes

b. Heat exchanger tube (power plants, petrochemical facilities)

c. Small diameter high-temperature steam lines

d. Subcritical and supercritical power plant tubing

Grade P91 steel pipe is suitable for large diameter, heavy wall piping in high-pressure and high-temperature systems:

a. Large diameter main steam piping (power plants)

b. Heavy wall headers and industrial pipelines

c. Hydrogen-rich and sulfur-containing service environments

We can provide high quality grade T91 and P91 alloy steel pipes for clients. The length can also be customized according to clients' requirements. Welcome to visit our website for more details.