ASTM A335 Grade P91 Creep Resistant Alloy Pipes
Modified 9% Chromium, 1% Molybdenum alloy fortified with Vanadium and Niobium for modern ultra-supercritical power plants.
ASTM A335 P91 / ASME SA335 P91 Main Steam & Reheat Pipe
Starlight Tubes is an approved manufacturer and exporter of ASTM A335 Grade P91 (Modified 9Cr-1Mo-V) seamless alloy steel pipes. Specifically formulated for the extreme steam temperatures and pressures of modern supercritical power generation, P91 provides unparalleled creep-rupture performance and oxidation resistance up to 650°C.
Our P91 pipes are manufactured with tight chemistry controls and precise normalized and tempered heat treatment cycles. Every single length is verified through 100% ultrasonic testing, hydrostatic testing, hardness testing (190-250 HB), and PMI verification.
Technical Specifications
ASTM / ASME CompliantTechnical Specifications — ASTM A335 Grade P91
Certified chemical limits and mechanical tensile properties for ASTM A335 P91
| Grade | C | Mn | P (max) | S (max) | Si | Cr | Mo | V | Nb | N |
|---|---|---|---|---|---|---|---|---|---|---|
| P91 | 0.08-0.12 | 0.30-0.60 | 0.020 | 0.010 | 0.20-0.50 | 8.00-9.50 | 0.85-1.05 | 0.18-0.25 | 0.06-0.10 | 0.03-0.07 |
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Certified ASTM A335 P91 High-Creep Piping
Starlight Tubes provides nuclear and power-plant certified P91 pipes with complete heat treatment verification, MTC 3.1/3.2, and global delivery.
Frequently Asked Questions on ASTM A335 Grade P91 9Cr-1Mo-V Pipes
Key engineering, tolerance, and international compliance answers from our metallurgical quality desk.
The additions of Vanadium (0.18-0.25%) and Niobium (0.06-0.10%) form fine MX carbonitrides that pin dislocations and provide extraordinary creep strength up to 650°C, allowing up to 50% thinner pipe walls.
Request Project Quotation for ASTM A335 Grade P91 9Cr-1Mo-V Pipes
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