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ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
Specifications
Place of Origin :
CHINA
Payment Terms :
L/C,T/T
Packaging Details :
plywood case, bundle with plastic cap
Length :
Single Random, Double Random & Cut Length
Material :
Grade P11
End :
Plain End, Beveled End
O.D. :
1/2" TO 24 " or large
MOQ :
500KGS
W.T. :
SCH 5 TO SCH XXS
Certification :
ABS, GL, DNV, NK, PED, AD2000, GOST9941-81, CCS, ISO 9001-2008
Standard :
ASTM A335 / ASME SA335
Product Name :
Alloy Steel Seamless Pipe
High Light :
ASTM A335 P11 Alloy Steel Seamless Pipe, High Temperature Alloy Steel Pipe
Brand Name :
YUHONG
Delivery Time :
7 DAYS
Model Number :
ASTM A335 P11 Alloy Steel Seamless Pipe
Description

ASTM A335 / ASME SA335 P11 Alloy Steel Seamless Pipe for High‑temperature Service

ASTM A335 Grade P11 is a seamless 1.25Cr-0.5Mo chrome moly alloy steel pipe designed for high-temperature power plant service, and Yuhong Group can supply it in a wide range of sizes with full certifications, third-party testing, and application-ready finishes. Because of its nominal composition of 1.25% Cr – 0.5% Mo provides enhanced creep strength and oxidation resistance up to ~570°C, making it suitable for superheater tubes, main steam lines, and headers in subcritical boilers and HRSGs. In power plants, P11 pipes are used in boilers, superheaters, heat exchangers, and high-pressure steam lines where materials must resist creep, oxidation, and thermal fatigue at elevated temperatures (typically up to ~570–600°C / 1050–1110°F).

Key Properties for Power Plant Use

Property Benefit
High-temperature creep resistance Withstands long-term stress at up to ~570°C without excessive deformation.
Oxidation resistance Chromium forms a protective oxide layer in steam/combustion gases.
Good thermal fatigue resistance Handles cyclic heating/cooling in boilers.
Weldability Acceptable with preheat (150–200°C) and post-weld heat treatment (PWHT).
Resistance to hydrogen attack Suitable for high-pressure hydrogen service (e.g., refinery/power applications).

Specifications of Alloy Steel Seamless Pipe

Standard ASTM A335, ASME SA335
Grade Gr. P5, P9, P11, P12, P21, P22 , P91, P92
Size 1/2" TO 24 "IN OD & NB or custom
Schedule SCH 5- SCH XXS, or custom
Type Seamless
Length Single Random, Double Random & Cut Length
End Plain End, Beveled End

Chemical composition(%) of ASTM A335 P-series Alloy Steel Seamless Pipe

Grade C Mn P≤ S≤ Si Cr Mo
P11 0.05-0.15 0.30-0.60 0.025 0.025 0.50-1.00 1.00-1.50 0.44-0.65
P22 0.05-0.16 0.30-0.60 0.025 0.025 ≤0.50 1.90-2.60 0.87-1.13
P5 ≤0.15 0.30-0.60 0.025 0.025 ≤0.50 4.00-6.00 0.45-0.65
P9 ≤0.15 0.30-0.60 0.025 0.025 0.25-1.00 8.00-10.00 0.90-1.10
P91 0.08-0.12 0.30-0.60 0.020/0.010 0.020/0.010 0.02-0.50 8.00-9.50 0.85-1.05
P92 0.07-0.13 0.30-0.60 0.020/0.010 0.020/0.010 ≤0.50 8.50-9.50 0.30-0.60

Mechanical properties of of ASTM A335 P-series Alloy Steel Seamless Pipe

Grade Tensile strength Yield strength Elongation
P11, P22, P5, P9 ≥415 ≥205 ≥30/20
P91 ≥585 ≥415 ≥20
P92 ≥620 ≥440 ≥20

Fabrication and Welding Requirements (for power plant)

  • Preheating Required: 150–200°C (300–400°F) before welding.

  • Post‑Weld Heat Treatment (PWHT) Mandatory: 700–760°C (1290–1400°F), hold 1 hour per 25 mm thickness.

  • Filler metals – Use matching composition: AWS A5.5 E8018-B2 (electrode) or ER80S-B2 (wire).

  • Nondestructive Examination (NDE) – Usually 100% radiography (RT) or ultrasonic (UT) for power plant high‑energy piping.

Applications

1. Superheater and Reheater Tubing

2. Main Steam Piping

3. Hot Reheat Piping
4. Boiler Headers and Manifolds
5. Heat Exchanger Tubing (Feedwater Heaters & Economizers)
6. High‑Pressure Steam Lines in Combined Cycle HRSGs
7. Chemical Injection / Sampling Lines

8. Power Plant

ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping

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ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping

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Product Detail
Place of Origin :
CHINA
Payment Terms :
L/C,T/T
Packaging Details :
plywood case, bundle with plastic cap
Length :
Single Random, Double Random & Cut Length
Material :
Grade P11
End :
Plain End, Beveled End
Contact Supplier
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping
ASTM A335 Grade P11 Alloy Steel Seamless Pipe Chrome Moly Pipe for Power Plant Piping

Yuhong Group Co.,Ltd

Verified Supplier
14 Years
zhejiang, ningbo
Since 2007
Business Type :
Manufacturer, Distributor/Wholesaler, Importer, Exporter, Trading Company, Seller, Other
Main Products :
Stainless Steel Seamless Pipe, Stainless Steel Seamless Tube, Duplex Stainless Steel Pipe
Total Annual :
50M-70M
Employee Number :
50~850
Certification Level :
Verified Supplier
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