GB/T 20409 Internally Threaded Seamless Multi Rifled Steel Pipes For High Pressure Boilers
GB/T 20409 Internally Threaded Seamless Multi-Rifled Steel Pipes For High-Pressure Boilers
Material
The GB/T 20409 standard specifies the use of internally threaded seamless multi-rifled steel pipes for high-pressure boilers. These pipes are made from specific materials that meet the requirements outlined in the standard. The main material used for these pipes is high-quality carbon structural steel.
Specification
The specification of GB/T 20409 Internally Threaded Seamless Multi-Rifled Steel Pipes for High-Pressure Boilers is as follows:
- Outer Diameter: 48mm - 457mm
- Wall Thickness: 3.5mm - 35mm
- Length: 4m - 12m
These specifications ensure that the pipes are suitable for use in high-pressure boiler applications, providing durability and reliability.
Chemical Composition
The chemical composition of the GB/T 20409 Internally Threaded Seamless Multi-Rifled Steel Pipes is as follows:
| Element | Composition (% by weight) |
|---|---|
| Carbon (C) | 0.27 - 0.35 |
| Silicon (Si) | 0.17 - 0.37 |
| Manganese (Mn) | 0.70 - 1.00 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.035 |
These specifications ensure the pipes have the necessary chemical properties for high-pressure boiler applications.
Mechanical Properties
The mechanical properties of the GB/T 20409 Internally Threaded Seamless Multi-Rifled Steel Pipes are as follows:
| Property | Value |
|---|---|
| Tensile Strength | ≥ 410 MPa |
| Yield Strength | ≥ 245 MPa |
| Elongation | ≥ 25% |
| Impact Toughness | ≥ 34 J/cm² |
| Hardness (HB) | ≤ 179 HB |
These mechanical properties ensure that the pipes can withstand high-pressure environments and provide sufficient strength and toughness.
Steel Grade
The GB/T 20409 standard defines the following steel grade for the internally threaded seamless multi-rifled steel pipes: 20G.
Application
The GB/T 20409 Internally Threaded Seamless Multi-Rifled Steel Pipes are primarily used in high-pressure boiler systems. These pipes are designed to withstand high temperatures and pressure conditions, making them suitable for use in various industries including power generation, chemical plants, and heating systems.
By utilizing the internally threaded design, these pipes offer enhanced heat transfer capabilities, improving the overall efficiency of high-pressure boilers. The excellent reliability and durability of these pipes ensure e and efficient operation in demanding boiler applications.


Haiyan Sanxin Steel Pipe Factory is a leading manufacturer of steel pipes in China. Located in a region with excellent geographical advantages, the factory is situated close to the Zhoushan Port and Ningbo Port.
Our factory covers an area of more than 25,000 square meters and has been in the steel pipe manufacturing business for 20 years. Over this period, we have accumulated a wealth of professional experience, which has helped us establish ourselves as a trusted name in the industry.
At our factory, we specialize in the production of various types of steel pipes, including stainless steel pipe, carbon steel pipe, copper pipe, steel pipe,seamless steel pipe and welded pipe. Our expertise in this field is evident from the 12 patents that we hold, which demonstrate our commitment to innovation and excellence.
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