safety valves play a vital role in ensuring the safe operation of a system by preventing the pressure of the medium in the pipeline or equipment from exceeding a preset safety range.
Safety valves, a special valve for safety protection, have closing parts that remain tightly closed when not acted upon by an external force. Once the pressure in the equipment or pipeline rises above the preset safety value, the safety valve will automatically open, by releasing the medium to the outside of the system, to prevent the pressure in the pipeline or equipment from continuing to rise. Safety valves belong to the category of automatic valves and are widely used on boilers, pressure vessels and piping systems to ensure that the pressure does not exceed the specified value, providing critical protection for personnel safety and equipment operation.
According to the opening height of the safety valve flap, we can categorize them into micro-opening safety valves and full-opening safety valves. The opening stroke height of the micro-opening safety valve is not more than 0.05 times the caliber of its minimum discharge throat; while the opening height of the full-opening safety valve is not more than 0.25 times the caliber of its minimum discharge throat.
From the structural form, the safety valve is mainly divided into pendant, lever, spring and pilot (also known as pulse). According to the structure of the valve body, it can be divided into closed and open type. Closed safety valves can be discharged to the designated location of all the media, does not leak into the external environment, usually used to deal with toxic or corrosive media. For air and steam systems, open-type safety valves are mostly used. When selecting a safety valve product, the actual sealing pressure needs to be determined. For spring-loaded safety valves, there may be a variety of operating pressure ratings for springs within the same nominal pressure (PN) range. Therefore, when ordering, in addition to stating the model number, name, medium and temperature of the safety valve, it is also necessary to specify the sealing pressure of the valve body, otherwise the supplier will supply according to the maximum sealing pressure.
When installing and maintaining safety valves, the following points need to be noted:
All types of safety valves should be installed vertically.
The outlet of the safety valve should be kept free from obstruction to avoid pressurization.
Before installing a safety valve, it should be specially tested and its sealing performance should be checked.
For safety valves in use, they should be inspected at regular intervals.
