What are the commonly used GB/T3087-2022 low and medium pressure boiler steel pipes in the industry

1. What is the standard for GB/T3087-2022 low and medium pressure boiler steel pipes?

GB/T3087-2022 is a national standard for seamless steel pipes used in low and medium pressure boilers, replacing the old version GB3087-2008. This standard specifies the dimensions, shape, weight, technical requirements, test methods, inspection rules, packaging, marking, and quality certificate of boiler steel pipes, ensuring their safe and reliable application in low and medium pressure boiler systems.

2. What are the materials and chemical compositions of GB/T3087-2022 low and medium pressure boiler steel pipes?

(1) Main materials: High-quality carbon structural steel, such as No. 10 steel and No. 20 steel. No. 20 steel is widely used due to its good physical and processing properties, with a carbon content not exceeding 0.17%.

(2) Chemical Composition: Carbon content ranges from 0.07% to 0.24%, silicon content from 0.17% to 0.37%, manganese content from 0.35% to 0.65%, and phosphorus and sulfur content each not exceeding 0.035%. This reasonable proportion of components ensures the strength and toughness of the boiler steel pipe.

3. What are the mechanical properties of low and medium pressure boiler steel pipes according to GB/T3087-2022?

(1) Tensile Strength: Generally between 335 and 550 MPa, reflecting the stability of the boiler steel pipe under high pressure and high-temperature environments.

(2) Yield Strength: Not less than 205 MPa (No. 10 steel) or 245 MPa (No. 20 steel), reflecting the deformation capacity of the boiler steel pipe under pressure.

(3) Elongation: Not less than 24% (No. 10 steel) or 20% (No. 20 steel), measuring the plastic deformation capacity of the boiler steel pipe to prevent cracking during use.

4. What are the dimensional specifications of low and medium pressure boiler steel pipes according to GB/T3087-2022?

(1) Outer diameter range: From 10mm to 720mm, common specifications include 159×6, 168×7, 273×9, 57×4, 60×4, 76×4, 89×4, etc.

(2) Wall thickness range: From 1.5mm to 100mm, a suitable wall thickness can be selected according to needs, balancing economy and safety.

(3) Length: Usually between 3000mm and 12500mm, with a permissible deviation of 0~+20mm for fixed length.

5. What are the application areas of low and medium pressure boiler steel pipes according to GB/T3087-2022?

(1) Boiler manufacturing: Low and medium pressure boiler steel pipes are used to manufacture key components of low and medium pressure boilers, such as water-cooled walls, superheaters, steam pipes, economizers, reheaters, flue pipes, and arch brick pipes.

(2) Other fields: Low and medium pressure boiler steel pipes can also be used for steam pipelines in the power, chemical, and petroleum industries, as well as for fluid pipelines such as oil, natural gas, coal gas, and water.

(3) Machinery manufacturing field: Low and medium pressure boiler steel pipes can be used for drive shafts, steering arms, support shafts, and flanges in the automotive, tractor, and diesel engine industries.

(4) Light industry and construction field: Low and medium pressure boiler steel pipes can be used as condenser tubes, water supply pipes, and structural pipes in bridges, buildings, and other fields.

6. Details of inspection and testing of low and medium pressure boiler steel pipes according to GB/T3087-2022:

(1) Hydrostatic test: Simulates the real pressure environment during boiler operation to test its pressure-bearing and sealing capabilities.

(2) Flattening test: Flattens the boiler steel pipe to the specified size, checks for cracks and fissures, and tests its plastic deformation capacity.

(3) Flaring test: Tests the ability of the boiler steel pipe to withstand radial expansion and verifies its toughness.

(4) Non-destructive testing, such as ultrasonic testing, eddy current testing, etc., ensuring no defects inside the boiler steel tubes.

7. What are the heat treatment processes for low and medium pressure boiler steel tubes according to GB/T3087-2022?

Most boiler steel tubes require heat treatment, such as normalizing. By heating to a suitable temperature and then air cooling, the grain size is refined, the microstructure is optimized, and the overall mechanical properties of the steel tube are improved, making it more suitable for the complex thermal conditions of the boiler.

8. What are the updates and improvements to the GB/T3087-2022 standard for low and medium pressure boiler steel tubes?

Compared to GB3087-2008, GB/T3087-2022 has been improved and optimized in several aspects, such as modifying the description of the scope of application, adding ordering information, and modifying dimensional tolerances, to better meet the needs of modern industry.