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Alloy Steel Pipes in Grades P5, P9, P11, P22 & P91 – Manufacturer and Supplier in UAE

Mcneil Alloys is a trusted manufacturer and supplier of Alloy Steel Pipes in P5, P9, P11, P22, and P91 grades, catering to critical industrial sectors across the UAE and international markets. Our alloy steel piping solutions are developed to perform reliably in high-temperature, high-pressure, and corrosive operating environments where material integrity and long-term service stability are essential.

We supply alloy steel pipes primarily for power generation, oil & gas, refineries, petrochemical plants, and heavy process industries, where chromium-molybdenum steels are specified for their superior strength, creep resistance, and thermal performance. Each grade we offer is selected and processed to meet the exact mechanical, chemical, and dimensional requirements demanded by modern industrial projects.

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End-to-End Alloy Steel Pipe Solutions with Engineering Expertise

At Mcneil Alloys, our focus goes beyond supply. We work closely with EPC contractors, plant operators, and engineering teams to ensure the right alloy grade, heat treatment condition, and specification are matched to the intended service conditions. From material selection to documentation and delivery, our alloy steel pipes are supplied with a strong emphasis on quality control, traceability, and project-specific compliance.

With coordinated supply capabilities from the UAE, we support both local project timelines and export requirements, delivering alloy steel pipes that integrate seamlessly into demanding operating systems and long-term industrial installations.

Types of Our Graded Pipes

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P5 Alloy Steel Pipe

Alloy Steel P5 Pipes offer good resistance to oxidation and corrosion while maintaining strength at elevated temperatures. They are commonly used in steam boilers, heat exchangers, and pressure piping systems within power plants, refineries, and high-temperature industrial applications.

P9 Alloy Steel Pipe

Alloy Steel P9 Pipes are designed for higher temperature service where increased chromium content improves oxidation resistance. These pipes are widely applied in refinery process lines, power plant piping, and systems handling hot gases and fluids under continuous thermal stress.

P11 Alloy Steel Pipe

Alloy Steel P11 Pipes are known for their ability to withstand high pressure and temperature conditions. They are extensively used in boiler tubes, superheaters, and steam pipelines where long-term strength and resistance to thermal fatigue are required.

P22 Alloy Steel Pipe

Alloy Steel P22 Pipes provide enhanced creep strength and thermal stability for severe service conditions. They are typically used in main steam lines, reheaters, and high-pressure piping systems in power generation, petrochemical, and refinery applications.

P91 Alloy Steel Pipe

Alloy Steel P91 Pipes are engineered for extreme temperature and pressure environments, offering excellent creep resistance and long-term structural stability. They are widely used in supercritical power plants, high-temperature steam lines, and advanced industrial process systems.

P5 Alloy Steel Pipe for Moderate High-Temperature Piping Systems

P5 alloy steel pipes are commonly supplied by Mcneil Alloys for applications involving moderate to high operating temperatures where oxidation resistance and mechanical stability are important. This grade is often used in refinery process lines, heat exchangers, and pressure piping systems that operate under steady thermal conditions. P5 provides dependable performance where long-term exposure to heat requires material consistency rather than extreme creep strength.

Key Highlights:

  • Suitable for moderate high-temperature service

  • Good resistance to oxidation and surface scaling

  • Stable mechanical properties under continuous heat

  • Commonly used in refineries and heat transfer systems

  • Maintains strength during prolonged heat exposure

P5 Alloy Steel Pipe – Technical Specification
Parameter Specification
Composition Chromium 4–6%, Molybdenum 0.45–0.65%
Temperature Range Suitable for service temperatures up to 600°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 85 HRB
Standards ASTM A335 / ASME SA335 (Grade P5)

P9 Alloy Steel Pipe Used in High-Temperature Refinery and Process Lines

Mcneil Alloys supplies P9 alloy steel pipes for systems exposed to higher temperatures where improved oxidation resistance is required. With increased chromium content, this grade performs well in refinery units, power plant piping, and process lines carrying hot fluids or gases. P9 is typically selected where operating conditions demand enhanced durability and resistance to thermal degradation over extended service periods.

Key Highlights:

  • Higher chromium content than P5

  • Improved resistance to oxidation at elevated temperatures

  • Suitable for refinery and power plant process piping

  • Maintains strength during prolonged heat exposure

P9 Alloy Steel Pipe – Technical Specification
Parameter Specification
Composition Chromium 8–10%, Molybdenum 0.9–1.1%
Temperature Range Suitable for service temperatures up to 650°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 90 HRB
Standards ASTM A335 / ASME SA335 (Grade P9)

P11 Alloy Steel Pipe for Boiler, Superheater, and Steam Line Applications

P11 alloy steel pipes supplied by Mcneil Alloys are widely used in applications involving high pressure and elevated temperatures, particularly in steam and boiler systems. This grade offers improved creep resistance, making it suitable for components subjected to sustained internal pressure and thermal stress. P11 is commonly specified for power generation and industrial steam distribution systems requiring reliable long-term performance.

Key Highlights:

  • Designed for high-pressure, high-temperature service

  • Improved creep resistance compared to lower alloy grades

  • Widely used in boilers, superheaters, and steam lines

  • Suitable for continuous-duty industrial applications

P11 Alloy Steel Pipe – Technical Specification
Parameter Specification
Composition Chromium 1–1.5%, Molybdenum 0.44–0.65%
Temperature Range Suitable for service temperatures up to 600°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 85 HRB
Standards ASTM A335 / ASME SA335 (Grade P11)

P22 Alloy Steel Pipe for Main Steam, Reheater, and High-Stress Piping

Mcneil Alloys provides P22 alloy steel pipes for severe service conditions where high temperature, pressure, and thermal cycling are present. This grade is frequently used in main steam lines, reheaters, and refinery piping systems exposed to fluctuating operating conditions. P22 offers enhanced resistance to deformation and thermal fatigue, supporting long service life in critical energy and process installations.

Key Highlights:

  • High creep strength for severe operating conditions

  • Strong resistance to thermal fatigue and deformation

  • Commonly used in power plants and refineries

  • Suitable for long-term, high-stress service

P22 Alloy Steel Pipe – Technical Specification
Parameter Specification
Composition Chromium 1.9–2.6%, Molybdenum 0.87–1.13%
Temperature Range Suitable for service temperatures up to 650°C
Tensile Strength ≥ 415 MPa
Yield Strength ≥ 205 MPa
Hardness ≤ 90 HRB
Standards ASTM A335 / ASME SA335 (Grade P22)

P91 Alloy Steel Pipe for Supercritical and High-Temperature Pressure Systems

P91 alloy steel pipes supplied by Mcneil Alloys are engineered for extreme temperature and pressure environments found in advanced power generation and high-efficiency industrial systems. Known for exceptional creep resistance and high strength, this grade is widely used in supercritical and ultra-supercritical steam applications. P91 supports improved plant efficiency while maintaining structural integrity over extended operating periods.

Key Highlights:

  • Exceptional creep resistance and high strength

  • Designed for extreme temperature and pressure service

  • Used in supercritical power plants and advanced systems

  • Supports long-term operational reliability and efficiency

P91 Alloy Steel Pipe – Technical Specification
Parameter Specification
Composition Chromium 8–9.5%, Molybdenum 0.85–1.05%, with controlled additions of Vanadium and Niobium
Temperature Range Suitable for service temperatures up to 700°C
Tensile Strength ≥ 620 MPa
Yield Strength ≥ 440 MPa
Hardness ≤ 100 HRB
Standards ASTM A335 / ASME SA335 (Grade P91)

Where These Alloy Steel Pipes Are Commonly Used

At Mcneil Alloys, P5, P9, P11, P22, and P91 alloy steel pipes are usually supplied for projects where operating temperature and pressure rule out carbon steel. Most enquiries we receive are tied to steam systems, refinery process lines, or plant upgrades where long-term thermal performance is critical.

These grades are typically specified for:

  • Boiler and superheater lines in power plants where steady high temperatures are involved

  • Main steam and reheater piping exposed to continuous pressure and thermal cycling

  • Refinery and petrochemical process lines handling hot hydrocarbons and gases

  • Heat exchangers and headers operating under sustained heat load

  • Plant revamp and replacement work where older piping needs upgrading to higher alloy grades

How Mcneil Alloys Supports Alloy Steel Pipe Projects

Supplying alloy steel pipes is not just about delivering material. In practice, most projects require confirmation that the selected grade, heat treatment, and testing match the service conditions. This is where Mcneil Alloys is involved beyond basic supply.

We typically support clients by:

  • Helping confirm whether P5, P11, P22, or P91 is more suitable based on operating data

  • Supplying pipes in the correct heat treatment condition as per project specifications

  • Coordinating documentation such as MTCs, PMI, and inspection reports before dispatch

  • Supporting EPC contractors during inspection and material approval stages

  • Managing deliveries in line with shutdown schedules or project timelines

Why Clients Continue to Work with Mcneil Alloys

Most of our repeat clients come back because they know what to expect. We focus on consistency, clear communication, and material that meets specifications without surprises.

Clients choose Mcneil Alloys because:

  • We regularly handle alloy steel grades used in power and refinery systems

  • Material is supplied with clear traceability and inspection-ready documentation

  • Technical discussions are handled practically, not theoretically

  • Orders are coordinated from the UAE with attention to project schedules

  • We understand the inspection and approval process on industrial sites

Talk to Us About Your Alloy Steel Pipe Requirement

If you’re working on a project involving P5, P9, P11, P22, or P91 alloy steel pipes, we’re happy to review your requirement and advise based on actual service conditions. Share your operating temperature, pressure, and application details, and our team will help you move forward with the right material and documentation.

Share Your Project Details and We’ll Advise on the Right Alloy Grade  

Frequently Asked Questions – Alloy Steel Pipes

How do I choose the right alloy steel pipe grade? +
Selection usually starts with operating temperature and pressure. Once these details are known, we can help determine whether grades such as P5, P11, P22, or P91 are most suitable for the intended service.
Can these alloy steel pipes handle continuous high temperatures? +
Yes. Alloy steel pipe grades are designed for continuous high-temperature service. They are commonly used in steam lines, boilers, refineries, and power plant systems where pipes operate under sustained heat and pressure.
What standards do you supply these alloy steel pipes to? +
These alloy steel pipes are primarily supplied in accordance with ASME SA335. If a project requires specific heat treatment, testing, or supplementary requirements, the supply can be aligned accordingly.
What documents will I receive with the pipes? +
Pipes are supplied with material test certificates including chemical and mechanical test results. Additional testing such as PMI or NDT can be arranged when required by the project before dispatch.
Can you supply for both UAE and export projects? +
Yes. We support both UAE-based and export projects, ensuring packing, marking, and documentation comply with site requirements as well as international shipping and inspection standards.