Pressure rating range of American standard boiler tubes

The pressure rating of American standard boiler tubes is mainly based on the ASME (American Society of Mechanical Engineers) standard. The following are common classifications:

1. Low-pressure boiler tubes

Pressure range: ≤15 psi (about 0.1 MPa)
Application: small heating systems, domestic hot water boilers and other low-pressure scenarios.

2. Medium-pressure boiler tubes

Pressure range: 15 psi to 800 psi (about 0.1 MPa to 5.5 MPa)

Application: industrial boilers, small power plant boilers and medium-sized heating systems.

3. High-pressure boiler tubes

Pressure range: 800 psi to 1500 psi (about 5.5 MPa to 10.3 MPa)
Application: large industrial boilers, power plant boilers and high-temperature and high-pressure steam systems.

4. Ultra-high-pressure boiler tubes

Pressure range: ≥1500 psi (about 10.3 MPa)
Application: large power plant boilers, nuclear power plant boilers and special industrial boilers.

Boiler tube classification in ASME standard:

ASME standard divides boiler tubes into the following categories according to the design and use conditions of the boiler:

Class I: Stationary steam boilers, usually with higher pressure.
Class II: Stationary hot water boilers, with relatively lower pressure.
Class III: High-pressure steam boilers, used for special industrial applications.
Class IV: Locomotive boilers, used for mobile equipment.
Class V: Electric boilers, used for electric heating systems.

Material selection:

Depending on the pressure level and operating temperature, the material selection of boiler tubes is also different:

Carbon steel: suitable for low-pressure and medium-pressure boilers.
Alloy steel: used for high-pressure and ultra-high-pressure boilers, with good high-temperature resistance and corrosion resistance.
Stainless steel: used in special environments such as high temperature, corrosive media, etc.

Detection and maintenance:

To ensure the safe operation of boiler tubes, the following inspections and maintenance are required regularly:

Non-destructive testing: such as ultrasonic and radiographic testing.
Pressure test: Perform water pressure tests regularly.
Corrosion inspection: Check the corrosion regularly and replace damaged pipes in time.

Conclusion:

The pressure level classification of American boiler tubes is mainly based on the ASME standard, covering multiple levels from low pressure to ultra-high pressure. Reasonable material selection, manufacturing and regular maintenance are the key to ensuring the safe operation of boilers.

Read more: Carbon steel ERW boiler tube & air heater tube specification