Safety valve selection principles are analyzed as follows:

1. steam boiler safety valve, generally used to open the entire Kai spring safety valve;
2. The liquid medium with a safety valve, generally used Weiqi safety valve spring;
3. The air or other gas media safety valve, generally used in the entire Kai spring safety valve closed;
4. LPG tankers or liquefied petroleum gas tanker railroad safety valve, generally used all Kai built-in Propane Control Valve;
5. outlet safety valve production wells, generally used in the pilot valve;
6. The high-pressure bypass valve steam generating equipment, generally used in a safe and controlled dual function of the pilot valve
7. If the requirements of the safety valve for regular open test should be used to enhance the wrench with a safety valve. When the pressure reaches more than 75% of the opening pressure of the medium can be used to enhance the wrench slightly lifted from the valve seat to check the safety valve opens flexibility;
8. If the medium temperature is higher, in order to reduce the temperature of the spring chamber, usually enclosed safety valve when the temperature exceeds 300 ℃ and open valve temperature than 350 ℃ and should be used in safety valve with radiator;
9. If the valve outlet back pressure is changing, the change amount exceeds 10% of the opening pressure should be used bellows safety valve;
10. If a corrosive medium should be used bellows safety valve, preventing the important parts due to media corrosion and failure.