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ASTM SA335 Alloy Steel Pipes Exporter In United Arab Emirates & Gulf - Mcneil Alloys

ASTM SA335 alloy steel pipes are not selected casually. They are used when piping systems operate beyond the limits of standard materials and where long-term performance under heat and pressure becomes a design requirement rather than a preference. These grades form the backbone of high-temperature piping networks in power generation, refining, and heavy process industries.

At Mcneil Alloys, ASTM SA335 pipes are handled as engineered materials, not off-the-shelf items. We supply grades P5, P9, P11, P22, and P91 with close attention to chemistry control, heat treatment condition, and dimensional consistency. Each grade is supplied with a clear purpose whether it is to resist oxidation, manage sustained pressure, or maintain strength during extended thermal exposure.

Our experience supplying ASTM SA335 alloy steel pipes in the UAE comes largely from projects where piping systems are expected to remain in service for years without failure. Some requirements involve moderate high-temperature lines, while others relate to steam systems, reheaters, or advanced power units operating at extreme conditions. The grade selection changes accordingly, and so does the supply approach.

Our ASTM SA335 Alloy Steel Pipes

ASTM P5 Alloy Steel Pipes

ASTM A335 P5 pipes contain chromium and molybdenum, providing good resistance to oxidation and high temperatures. They are commonly used in heat exchangers, boilers, and refinery piping systems.

ASTM P9 Alloy Steel Pipes

ASTM A335 P9 pipes offer improved oxidation resistance due to higher chromium content. These pipes are suitable for refinery and power plant piping exposed to continuous high-temperature service.

ASTM P11 Alloy Steel Pipes

ASTM A335 P11 pipes are designed for high-pressure and high-temperature applications. They provide better creep resistance and are widely used in boilers, superheaters, and steam piping systems.

ASTM P22 Alloy Steel Pipes

ASTM A335 P22 pipes are used for severe temperature and pressure conditions. Their higher alloy content supports long-term strength, making them ideal for main steam and reheater lines.

ASTM P91 Alloy Steel Pipes

ASTM A335 P91 pipes are high-strength alloy steel pipes developed for extreme temperature and pressure service, commonly used in supercritical power plants and advanced high-efficiency systems.

ASTM A335 Grade P5 Alloy Steel Pipes

At Mcneil Alloys, Grade P5 pipes are usually supplied for systems where temperature is high but operating conditions remain stable. This grade is often chosen during refinery upgrades and heat-transfer projects where oxidation resistance is required without moving to higher-cost alloys. P5 works well when consistency and long service life matter more than extreme pressure capability.

Key Highlights:

  • Suitable for steady high-temperature operation

  • Reliable oxidation resistance in refinery environments

  • Commonly used in heat exchangers and boiler piping

  • Cost-effective choice for moderate thermal stress

Technical Specification
Parameter Specification
Composition Chromium 4–6%, Molybdenum 0.45–0.65%
Temperature Range Up to 600°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 85 HRB
Standards ASTM A335 / ASME SA335

ASTM A335 Grade P9 Alloy Steel Pipes

Grade P9 is supplied when operating temperatures increase and surface degradation becomes a concern over time. We often see this grade specified in hot process lines where pipes remain under continuous heat. Compared to P5, P9 offers improved resistance to scaling, making it a safer option for long-running refinery and power plant systems.

Key Highlights:

  • Higher chromium content for better heat resistance

  • Reduced scaling in continuous high-temperature service

  • Used in refinery and thermal process piping

Technical Specification
Parameter Specification
Composition Chromium 8–10%, Molybdenum 0.9–1.1%
Temperature Range Up to 650°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 90 HRB
Standards ASTM A335 / ASME SA335

ASTM A335 Grade P11 Alloy Steel Pipes

P11 pipes are commonly requested when pressure joins temperature as a critical factor. At Mcneil Alloys, this grade is frequently supplied for boilers and steam systems where pipes operate under constant load. P11 is valued for its balance between strength and workability, especially in power generation environments.

Key Highlights:

  • Designed for combined high pressure and temperature

  • Improved creep resistance over lower grades

  • Widely used in steam lines and superheaters

  • Suitable for continuous industrial operation

Technical Specification
Parameter Specification
Composition Chromium 1–1.5%, Molybdenum 0.44–0.65%
Temperature Range Up to 600°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 85 HRB
Standards ASTM A335 / ASME SA335

ASTM A335 Grade P22 Alloy Steel Pipes

Grade P22 is selected for more demanding systems where thermal cycling and long service life are major design considerations. We typically supply this grade for main steam and reheater lines where material failure is not acceptable. P22 performs well under fluctuating temperatures and sustained mechanical stress.

Key Highlights:

  • High creep strength for severe service

  • Handles thermal cycling effectively

  • Used in main steam and reheater applications

  • Proven reliability in power plants and refineries

Technical Specification
Parameter Specification
Composition Chromium 1.9–2.6%, Molybdenum 0.87–1.13%
Temperature Range Up to 650°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 90 HRB
Standards ASTM A335 / ASME SA335

ASTM A335 Grade P91 Alloy Steel Pipes

P91 pipes sit at the highest end of the SA335 range and are supplied only when operating conditions justify it. At Mcneil Alloys, this grade is handled with particular care due to its strict heat treatment and inspection requirements. It is typically used in supercritical systems where efficiency, strength, and long-term stability are critical.

Key Highlights:

  • Exceptional strength at extreme temperatures

  • Excellent long-term creep resistance

  • Used in supercritical and advanced power systems

  • Requires controlled processing and inspection

Technical Specification
Parameter Specification
Composition Chromium 8–9.5%, Molybdenum 0.85–1.05%, with Vanadium and Niobium
Temperature Range Up to 700°C
Tensile Strength ≥ 620 MPa
Yield Strength ≥ 440 MPa
Hardness ≤ 100 HRB
Standards ASTM A335 / ASME SA335

What Is the Difference Between ASME and ASTM Pipes?

This is a question we hear often, and the confusion is understandable.

ASTM defines the material specification. It tells you what the pipe is made of — the chemical composition, mechanical properties, and testing requirements. For example, ASTM A335 defines the material requirements for alloy steel pipes such as P5, P11, P22, and P91.

ASME, on the other hand, applies those same material specifications for pressure equipment and piping systems. When a pipe is supplied as ASME SA335, it means the ASTM A335 material is accepted and used under ASME pressure code rules.

In simple terms:

  • ASTM controls the material

  • ASME controls how that material is used in pressure systems

We supply pipes to ASTM or ASME requirements based on how the piping system will be designed, inspected, and approved.

Applications of ASME / ASTM A335 Alloy Steel Pipes

ASME / ASTM A335 alloy steel pipes are used when piping systems operate beyond the limits of carbon steel. We typically supply these grades for systems where heat, pressure, and long service life all come into play.

Common applications include:

  • Boiler, superheater, and steam piping systems

  • Main steam and reheater lines in power plants

  • Refinery process piping handling hot hydrocarbons

  • Petrochemical and chemical processing units

  • High-temperature headers and pressure lines

  • Replacement piping during plant shutdowns

The grade selection depends on operating temperature, pressure, and how long the system is expected to remain in service.

Why Choose Mcneil Alloys for ASME / ASTM A335 Pipes

When you work with us, you’re not just buying a pipe grade  you’re working with a team that understands how these materials behave in real systems.

We focus on supplying pipes in the correct condition, with the right documentation, so you don’t face delays during inspection or installation.

Why clients prefer working with us:

  • We help you confirm whether ASTM or ASME supply is required

  • Pipes are supplied with proper heat treatment and traceability

  • Documentation is clear and inspection-ready

  • We understand approval requirements on industrial project sites

  • Supply is coordinated from the UAE for local and export projects

Our goal is simple: deliver material that installs smoothly and performs as expected over time.

Let’s Discuss Your Alloy Steel Pipe Requirement

If you’re sourcing ASTM A335 or ASME SA335 alloy steel pipes and want to be sure the specification, grade, and supply condition are correct, talk to us early. Share your operating conditions and project requirements, and we’ll help you move forward with confidence. Contact Mcneil Alloys today   and let’s get the specification right from the start.

Talk to Mcneil Alloys today and let’s get it right from the start.  

Frequently Asked Questions

What does ASTM mean in alloy steel pipes? +
ASTM defines the material standard for alloy steel pipes. It specifies the required chemical composition, mechanical strength, and testing criteria that the pipe must meet before it can be used in industrial applications.
Are ASTM A335 pipes suitable for high temperature use? +
Yes. ASTM A335 alloy steel pipes are designed for high-temperature and high-pressure service. They are commonly used in boilers, steam lines, refineries, and power plants where elevated temperatures are present.
Can ASTM A335 pipes be used in pressure systems? +
ASTM A335 pipes can be used in pressure systems when the project allows ASTM material standards. If the system follows ASME pressure codes, the same material is supplied as ASME SA335.
What documents do I get with ASTM alloy steel pipes? +
Pipes are supplied with material test certificates showing chemical and mechanical properties. Additional testing such as PMI or NDT can be arranged if required by the project or client.
How do I know which ASTM A335 grade I should use? +
Grade selection depends on operating temperature, pressure, and service conditions. Once these details are reviewed, it becomes easier to determine whether grades such as P5, P9, P11, P22, or P91 are suitable for the application.