The setting pressure refers to the predetermined pressure when the valve disc of the safety valve starts to open under operating conditions, and is the gauge pressure measured at the valve inlet. Under this pressure, under the specified operating conditions, the force caused by the medium pressure to open the valve and the force to keep the valve flap on the valve are balanced with each other. Under this pressure, there is a measurable opening height, and the medium is in a continuous discharge state that can be perceived visually or audibly.

蒸汽锅炉用安全阀 Safety valve for steam boiler

a. The set pressure of the safety valve on the drum (shell) and the superheater should be in accordance with Table 1.

b. The setting pressure of the safety valve of the economizer, reheater, and once-through boiler start-up separator is 1.1 times the working pressure of the installation site.

c. Setting pressure deviation: ± 0.015 MPa when the setting pressure is 0.5 MPa or less, ± 3% of the setting pressure when the setting pressure is 0.5 to 2.3 MPa, and ± 0.07 MPa when the setting pressure is 2.3 to 7.0 MPa, when When the setting pressure is greater than 7.0MPa, it is ± 1% of the setting pressure.

Table 1: Set pressure of the safety valve on the drum (shell) and the superheater

Note: There must be a safety valve on the boiler, which should be adjusted according to the lower setting pressure in the table. For boilers with superheaters, the safety valve adjusted at a lower pressure must be a safety valve on the superheater to ensure that the safety valve on the superheater opens first. The working pressure in the table refers to the working pressure of the impulse outlet at the impulse safety valve, and to the working pressure of the safety valve device at other types of safety valves.

热水锅炉用安全阀 2.Safety valve for hot water boiler

a. The setting pressure of the safety valve should be in accordance with Table 2.

b. Setting pressure deviation: ± 0.015MPa when the setting pressure is 0.5 MPa or less, and ± 3% of the setting pressure when the setting pressure is greater than 0.5MPa.

Table 2

Note: There must be a safety valve on the boiler to adjust according to the lower setting pressure in the table. The working pressure here refers to the working pressure of the components directly connected to the safety valve.

固定式压力容器用安全阀 3.Safety valve for fixed pressure vessel

a. When only one safety valve is installed on the fixed pressure vessel, the setting pressure of the safety valve should not be greater than the design pressure of the pressure vessel; when multiple safety valves are installed on the fixed pressure vessel, the setting pressure of one of the safety valves should not be greater than the pressure. The design pressure of the container and the setting pressure of the other safety valves can be appropriately increased, but it must not exceed 1.05 times the design pressure.

b. Setting pressure deviation: ± 0.015MPa when the setting pressure is 0.5 MPa or less, and ± 3% of the setting pressure when the setting pressure is greater than 0.5MPa.

移动式压力容器用安全阀 4.Safety valve for mobile pressure vessel

a. The setting pressure of the safety valve is 1.05 to 1.10 times the design pressure of the tank, and the return pressure is not less than 0.8 times the opening pressure. The setting pressure of the low temperature cryogenic tank truck safety valve must not exceed the design pressure of the tank.

b. Setting pressure deviation: ± 0.015MPa when the setting pressure is 0.5 MPa or less, and ± 3% of the setting pressure when the setting pressure is greater than 0.5MPa.

压力管道用安全阀 5.Safety valve for pressure pipeline

a. The setting pressure of the safety valve for industrial metal pipelines is 1.05 to 1.1 times the maximum working pressure; the setting pressure of safety valves for pipelines in oil and gas stations is 1.05 to 1.15 times the maximum working pressure.

b. Setting pressure deviation: ± 0.015MPa when the setting pressure is 0.5 MPa or less, and ± 3% of the setting pressure when the setting pressure is greater than 0.5MPa.

医用高压氧舱用安全阀 6. Medical high-pressure oxygen chamber safety valve

a. The setting pressure of the safety valve is the maximum working pressure +0.02 MPa.

b. The setting pressure deviation is ± 0.015MPa.

压缩机用安全阀 7.Safety valve for compressor

a. The setting pressure of the safety valve is the maximum working pressure +0.02 MPa.

b. Setting pressure deviation: ± 0.015MPa when the setting pressure is 0.5 MPa or less, and ± 3% of the setting pressure when the setting pressure is greater than 0.5MPa.


Source: Voice of Valve