ASTM A335 Alloy Steel Pipe (P5–P91) Supplier
ASTM A335 alloy steel pipe is a chrome molybdenum seamless steel pipe series designed for high temperature, high pressure, and critical industrial applications. It is widely used in power plants, boiler systems, oil refineries, and petrochemical plants where long-term thermal stability and creep resistance are required.
We supply full grades including:
👉 P5 / P9 / P11 / P22 / P91 ASTM A335 pipes
Experience – Global Industrial Supply
We have extensive experience supplying ASTM A335 alloy steel pipes for EPC projects and industrial systems worldwide, including:
Power generation plants
Refinery and petrochemical projects
Boiler manufacturing industries
High-pressure steam pipeline systems
Our materials are used in critical temperature and pressure environments.
Expertise – Engineering Understanding
ASTM A335 pipes are alloyed with Chromium (Cr) and Molybdenum (Mo) to improve high-temperature performance:
Creep resistance under long-term stress
Oxidation and scaling resistance
High mechanical strength at elevated temperatures
Stable performance in pressure systems
Grade Engineering Summary
P5 – High corrosion resistance (refinery use)
P9 – Balanced Cr-Mo performance
P11 – Standard boiler & steam pipe material
P22 – High-temperature power plant grade
P91 – Ultra high-strength advanced alloy steel
Authoritativeness – Standards Compliance
ASTM A335 alloy steel pipes are manufactured according to:
ASTM A335 / ASME SA335
ASME Boiler & Pressure Vessel Code (BPVC)
EN / ISO international standards
Inspection & Testing
Hydrostatic test
Ultrasonic test (UT)
Chemical composition analysis
Mechanical property testing
Third-party inspection (SGS / BV / TUV optional)
Trustworthiness – Quality Assurance
We ensure full traceability and strict quality control:
Heat number traceability
Mill Test Certificate (EN 10204 3.1 / 3.2)
Dimensional inspection (OD / WT / length)
Non-destructive testing (NDT)
Final export inspection before shipment
ASTM A335 Pipe Grades We Supply
🔹 ASTM A335 P5 Pipe
High corrosion resistance alloy steel pipe for refinery and chemical systems.
🔹 ASTM A335 P9 Pipe
Balanced high-temperature performance for industrial process piping.
🔹 ASTM A335 P11 Pipe
Most widely used grade for boiler and steam pipeline systems.
🔹 ASTM A335 P22 Pipe
High-performance material for power plant high-temperature service.
🔹 ASTM A335 P91 Pipe
Advanced alloy steel for ultra-high temperature and critical pressure systems.
👉 Each grade is available in seamless form with customized sizes.
APPLICATIONS
ASTM A335 alloy steel pipes are widely used in:
Boiler superheater & reheater tubes
High-pressure steam pipelines
Power plant thermal systems
Petrochemical cracking units
Oil refinery processing lines
Heat exchanger systems
Industrial furnace systems
WHY CHOOSE US
✔ Full range of ASTM A335 grades (P5–P91)
✔ Stable mill supply with large stock capability
✔ Strict quality control system
✔ Fast global export delivery
✔ Third-party inspection support
✔ Competitive factory pricing
TECHNICAL SERVICE SUPPORT
We provide technical support for:
Material selection guidance (P5 vs P11 vs P22 vs P91)
Project specification matching
Heat treatment requirements
Welding and fabrication recommendations
ASTM A335 GRADE SELECTION GUIDE
👉 Choose the correct grade:
P5 → refinery corrosion environments
P9 → medium-high temperature systems
P11 → standard boiler & steam pipelines
P22 → power plant high-temperature systems
P91 → ultra-critical pressure systems
FAQ
❓ 1. What is ASTM A335 pipe used for?
ASTM A335 alloy steel pipes are used for high-temperature and high-pressure service applications, mainly in power plants, boilers, oil refineries, and petrochemical industries. They are designed for steam lines, heat exchangers, and critical pressure systems.
❓ 2. What is the difference between ASTM A335 grades P5, P9, P11, P22, and P91?
Each grade has different chromium and molybdenum content, affecting temperature resistance and strength:
P5 – High corrosion resistance (refinery service)
P9 – Medium-high temperature applications
P11 – General boiler and steam pipelines
P22 – Higher temperature power plant systems
P91 – Ultra-high strength for critical pressure service
❓ 3. Is ASTM A335 a seamless pipe?
Yes. ASTM A335 specifies seamless ferritic alloy steel pipes only, designed for high-temperature service conditions.
❓ 4. What is the maximum temperature for ASTM A335 P11 pipe?
ASTM A335 P11 pipe is typically used in high-temperature service up to around 540°C (1000°F) depending on design pressure and system conditions.
❓ 5. What industries use ASTM A335 alloy steel pipes?
ASTM A335 pipes are widely used in:
Power generation plants
Oil and gas refineries
Petrochemical processing units
Boiler and heat exchanger systems
Industrial furnace systems
❓ 6. What is the difference between P11 and P22 pipe?
P22 contains higher chromium content (2.25%) compared to P11 (1.25%), which gives P22 better high-temperature strength and creep resistance, making it suitable for more demanding power plant applications.
❓ 7. Can ASTM A335 pipes be welded?
Yes, they can be welded, but proper preheating and post-weld heat treatment (PWHT) are required, especially for higher grades like P22 and P91.
❓ 8. What testing is required for ASTM A335 pipes?
Standard testing includes:
Hydrostatic testing
Ultrasonic testing (UT)
Chemical composition analysis
Mechanical property testing
Non-destructive testing (NDT)
❓ 9. What is the standard for ASTM A335 pipe?
ASTM A335 / ASME SA335 standard covers seamless ferritic alloy steel pipes for high-temperature service.
❓ 10. What certificate is provided with ASTM A335 pipes?
We provide Mill Test Certificate (EN 10204 3.1 / 3.2) including chemical composition, mechanical properties, and heat number traceability.
ASTM A335 alloy steel pipes (P5–P91) are essential materials for high-temperature and high-pressure industrial applications. With excellent creep resistance, oxidation resistance, and mechanical stability, they are widely used in power plants, boilers, refineries, and petrochemical industries.
Choosing the correct grade ensures safety, efficiency, and long service life in critical systems.
