Pressure bearing capacity of boiler tubes

Boiler tubes are steel products with openings at both ends and a hollow structure, characterized by a high length-to-circumference ratio. Based on the production method, they are classified into seamless steel tubes and welded steel tubes. Their specifications are typically expressed in terms of external dimensions (such as outer diameter or side length) and wall thickness. The size range varies widely, from small capillary tubes to large-diameter pipes measuring several meters.

As critical components in industrial boiler systems, the pressure-bearing capacity of boiler tubes is directly related to system safety and operational efficiency. So, how much pressure can boiler tubes withstand?

Pressure Capacity of Boiler Tubes

High-pressure boiler tubes can typically withstand pressures above 6.4 MPa.

The exact pressure limit depends on factors such as material, specifications, and operating environment.

It is essential to follow manufacturer technical specifications and safe pressure guidelines.

Key Factors Affecting Pressure Bearing Capacity

1. Material Properties

Yield strength and tensile strength directly determine the pressure limit.

Different materials (such as carbon steel and alloy steel) have significantly different performance characteristics in terms of pressure resistance, temperature tolerance, and corrosion resistance.

2. Specifications

Wall thickness: The thicker the pipe wall, the stronger the pressure-bearing capacity.

Outer diameter: Affects the structural stability of the pipeline.

3. Operating Conditions

Temperature: High temperatures reduce material strength.

Pressure fluctuations: Frequent changes in pressure can cause fatigue damage to the material.

Pressure Levels and Safety Requirements

Low pressure: Suitable for small boilers or low-temperature hot water systems. Although the safety requirements are lower, regular inspection and maintenance are still necessary.

Medium pressure: Common in industrial boilers and thermal systems. Pipes and valves at this level must comply with strict material selection, design, installation, and maintenance standards to prevent leaks or explosions.

High pressure: Used in power station boilers and high-temperature thermal systems. This level demands high-pressure resistance and sealing performance, along with safety valves and control systems.

Ultra-high pressure: Found in specialized industries such as petrochemicals. These systems require specialized design, manufacturing processes, and stricter safety management measures.

Safety Measures for Boiler Tube Usage

1. Material Selection and Specifications

Choose appropriate materials based on actual working conditions (e.g., GB5310 high-pressure boiler tubes).

Wall thickness calculations must comply with standards such as ASME BPVC.

2. Installation Standards

Follow regulatory guidelines such as TSG G0001.

Welding processes must undergo non-destructive testing (e.g., radiographic testing).

3. Operation and Maintenance Management

Regular inspections: Conduct wall thickness measurements (ultrasonic thickness gauge) and corrosion assessments.

Defect handling: Replace cracked or severely thinned pipes promptly.

Safety accessories: Install safety valves (activation pressure ≤ 1.05 times the design pressure).

4. Operational Guidelines

Overpressure operation is strictly prohibited (working pressure ≤ 80% of design pressure).

Startup and shutdown procedures must adhere to controlled pressure increase/decrease rates (≤ 0.5 MPa/min).

Conclusion

Understanding the pressure-bearing capacity of boiler tubes and ensuring their safe operation is critical for maintaining the stability and safety of industrial boiler systems. In practical applications, various factors such as material selection, specifications, operating conditions, and safety protocols must be carefully considered to ensure optimal performance and long-term reliability.