GB 3087 Grade 20 seamless boiler pipes generally have excellent high temperature resistance due to the need to handle high temperature and high pressure conditions in boilers. They usually have relatively thin wall thickness to improve heat conduction properties.
The specifications of GB 3087 Grade 20 pipes usually include the size, wall thickness, length and allowable deviation of the pipe, which are selected based on specific project needs.
This type of pipe is usually manufactured seamlessly to ensure its pressure resistance and reliability under high temperatures and pressures.
Chemical composition of GB 3087 Grade 20
Grade | Chemical Composition(%) | |||||||
C | Si | Mn | P | S | Cr | Cu | Ni | |
20 | 0.17~0.23 | 0.17~0.37 | 0.38~0.65 | ≤0.030 | ≤0.030 | 0.3~0.65 | ≤0.25 | ≤0.30 |
Mechanical properties of GB 3087 Grade 20
Grade | Wall thickness (mm) |
Tensile strength (MPa) |
Yield Strength (MPa) |
Elongation % |
≥ | ||||
20 | <15 | 410~550 | 245 | 20 |
≥15 | 225 |
Allowable deviation of outer diameter and wall thickness
Type of steel pipe | Outer diameter(mm) | Tolerance | ||
ordinary | advanced | |||
Hot rolled tube | OD | ≤159 | ±10%(min±0.50mm) | ±0.75%(min±0.40mm) |
>159 | ±1.0% | ±0.90% | ||
WT | ≤20 | +15.0%(min+0.45mm) -12.5% -0.35mm) |
±10%(min±0.30mm) | |
>20 | ±12.5% | ±10% | ||
OD≥351 | ±15% | |||
Cold drawn tube | OD | 10~30 | ±0.40mm | ±0.20mm |
>30~50 | ±0.45mm | ±0.25mm | ||
>50 | ±1.0% | ±0.75% | ||
WT | 1.5~3.0 | +15% -10% |
±10% | |
>3.0 | +12.5% -10% |
±10% |
The company's strength lies in the high quality and reliability of its products. We use advanced production processes and equipment to ensure that our steel pipe products have excellent quality and performance. In addition, we also focus on material selection and quality control to ensure product quality from the source. Our steel pipe products undergo strict inspection and testing and comply with relevant standards and customer requirements.