Each boiler should be equipped with at least two safety valves (including drum and superheater safety valves). If one of the following provisions is met, only one safety valve can be installed:
1. Steam boilers with a rated evaporation capacity ≤ 0.5t/h;
2. Steam boilers with a rated evaporation capacity < 4t/h and equipped with a reliable overpressure interlocking protection device;
3. Hot water boilers with a rated thermal power ≤ 2.8MW.
Safety valves should also be installed at the following locations:
1. At the outlet of the reheater and on the external start-up (steam-water) separator of the direct current boiler;
2. In the superheated steam system of the direct current steam boiler, before the stop valve of the connecting pipe between the two stages;
3. For waste heat boilers with multiple pressure levels, on the drum and superheater of each pressure level.
Selection of safety valves
1. The safety valves of steam boilers shall be full-open spring safety valves, lever safety valves or controlled safety valves (pulse, pneumatic, hydraulic and electromagnetic, etc.). The safety valves selected shall comply with the "Safety Technical Supervision Regulations for Safety Valves" and relevant technical standards;
2. For steam boilers with a rated working pressure of ≤0.1Mpa, static weight safety valves or water-sealed safety devices may be used. When a water-sealed safety device is installed on a hot water boiler, a safety valve may not be installed; the inner diameter of the water-sealed pipe of the water-sealed safety device shall be determined according to the rated evaporation capacity (rated thermal power) and rated working pressure of the boiler, and shall not be less than 25mm. No valves shall be installed, and anti-freezing measures shall be taken.
Each boiler should be equipped with at least two safety valves (including drum and superheater safety valves). If one of the following provisions is met, only one safety valve can be installed:
1. Steam boilers with a rated evaporation capacity ≤ 0.5t/h;
2. Steam boilers with a rated evaporation capacity < 4t/h and equipped with a reliable overpressure interlocking protection device;
3. Hot water boilers with a rated thermal power ≤ 2.8MW.
Safety valves should also be installed at the following locations:
1. At the outlet of the reheater and on the external start-up (steam-water) separator of the direct current boiler;
2. In the superheated steam system of the direct current steam boiler, before the stop valve of the connecting pipe between the two stages;
3. For waste heat boilers with multiple pressure levels, on the drum and superheater of each pressure level.
Selection of safety valves
1. The safety valves of steam boilers shall be full-open spring safety valves, lever safety valves or controlled safety valves (pulse, pneumatic, hydraulic and electromagnetic, etc.). The safety valves selected shall comply with the "Safety Technical Supervision Regulations for Safety Valves" and relevant technical standards;
2. For steam boilers with a rated working pressure of ≤0.1Mpa, static weight safety valves or water-sealed safety devices may be used. When a water-sealed safety device is installed on a hot water boiler, a safety valve may not be installed; the inner diameter of the water-sealed pipe of the water-sealed safety device shall be determined according to the rated evaporation capacity (rated thermal power) and rated working pressure of the boiler, and shall not be less than 25mm. No valves shall be installed, and anti-freezing measures shall be taken.