ASTM A335 / ASME SA335 Alloy Steel P11 Seamless Pipe for Boiler
A335 P11 seamless pipe typically undergoes a heat treatment process called
normalization and tempering. This process helps improve the pipe's
mechanical properties, such as strength and toughness, while
reducing internal stresses. A335 P11 seamless pipe is often
supplied with a protective coating or surface treatment to prevent
corrosion during transportation and storage. Common surface
treatments include varnish, oil coating, or painting. The seamless
pipe offers good resistance to oxidation, which helps protect it
from corrosive environments. However, it is important to note that
it is not as corrosion-resistant as stainless steel.
Specifications of Alloy Steel Seamless Pipe
| Standard | ASTM A335, ASME SA335 |
| Grade | Gr. P5, P9, P11, P12, P21, P22 , P91 |
| Size | 1/2" TO 24 "IN OD & NB |
| Schedule | SCH 5- SCH XXS |
| Type | Seamless / Fabricated |
| Length | Single Random, Double Random & Cut Length |
| End | Plain End, Beveled End |
Chemical composition(%)
| 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
| Grade | Tensile strength | Yield strength | Elongation |
| P11, P22, P5, P9 | ≥415 | ≥205 | ≥30/20 |
| P91 | ≥585 | ≥415 | ≥20 |
| P92 | ≥620 | ≥440 | ≥20 |
Here are some key advantages and reasons for alloy pipes' usage:
1. High-temperature Resistance: A335 P11 tubes are specifically
designed to withstand high temperatures, making them suitable for
applications that involve elevated temperatures and pressures. They
have good creep and rupture strength, allowing them to withstand
prolonged exposure to high heat without significant deformation or
failure.
2. Corrosion Resistance: These tubes are made with alloyed steel,
which provides excellent resistance to corrosion and oxidation.
This makes them suitable for use in environments that involve
corrosive substances, such as oil, gas, and chemical industries.
3. Strength and Durability: A335 P11 tubes have high tensile
strength and toughness, allowing them to withstand demanding
operating conditions. Their robust construction ensures long-term
performance, reducing the risk of leaks or failures.
4. Versatility: P11 tubes offer versatility in terms of application
due to their compatibility with various processes and industries.
They can be used in power plants, refineries, petrochemical
industries, oil and gas sectors, and high-temperature applications.
5. Seamless Design: A335 P11 tubes are manufactured through a
seamless production process, ensuring a consistent and uniform structure throughout the tube
length. This makes them resistant to cracking and enhances their
overall performance.
6. Cost-effectiveness: A335 P11 tubes provide a balance between
performance and cost, making them a cost-effective choice for many
applications. Their durability and resistance to corrosion reduce
the need for frequent replacements or repairs, resulting in lower
maintenance and operational costs over time.
Applications
Here are some common usages of A335 P11 seamless pipes:
1. Power Plants: A335 P11 pipes are widely used in power plants for
various applications such as steam pipelines, superheater tubes,
and reheater tubes. They can withstand high temperatures and
pressures, making them suitable for power generation processes.
2. Petrochemical Refineries: P11 pipes find extensive use in
petrochemical refineries for transporting various fluids, including
oil, gas, and chemicals. They are commonly employed in pipelines,
heat exchangers, and boilers within these facilities.
3. Oil and Gas Industries: A335 P11 pipes are utilized in the oil
and gas industries for both upstream and downstream operations.
They are used in exploration, production, and transportation of oil
and gas, including applications such as drilling, extraction, and
refining.
4. Boiler Applications: P11 pipes are commonly used in boilers due
to their high-temperature resistance and corrosion resistance
properties. They are employed in both industrial and commercial
boilers for steam generation and heat transfer processes.
5. High-Temperature Applications: These pipes are suitable for
various high-temperature applications across different industries.
They are often used in environments where resistance to heat and
pressure is critical, such as chemical processing plants, thermal
power plants, and heat recovery steam generators (HRSGs).
6. Heat Exchangers: A335 P11 pipes are employed in heat exchangers
to facilitate efficient heat transfer between two fluids at
different temperatures. They provide excellent thermal conductivity
and durability, making them suitable for this application.
