The high-pressure safety valve is a safety protection valve, and its opening and closing parts are normally closed under the action of external force. It is divided according to the structural form, which can be divided into plumb type, lever type, spring type and pilot type; according to the structure of the valve body, it can be divided into closed type and non-closed type. The following are the items that should be paid attention to when installing the high pressure safety valve:
1. For boilers with a rated evaporation capacity greater than 0.5t/h, install at least two safety valves; for boilers with a rated evaporation capacity less than or equal to 0.5t/h, install at least one safety valve; for boilers with a rated steam pressure less than or equal to 3.82MPa For boilers, the safety valve throat diameter should not be less than 25mm; for boilers with a rated steam pressure greater than 3.82MPa, the safety valve throat diameter should not be less than 20mm.
2. The high-pressure safety valve should be installed vertically at the highest position of the boiler and header. Between the safety valve and the drum or header, there shall be no outlet pipes and valves for taking steam.
3. The lever-type safety valve must have a device to prevent the heavy hammer from moving by itself and a guide frame to limit the lever's deviance, and the spring-type safety valve must have a device to lift the handle and prevent the adjustment screw from being twisted casually.
4. The cross-sectional area of the connecting pipe between the high-pressure safety valve and the boiler should not be less than the inlet cross-sectional area of the safety valve. If several safety valves are installed on a short pipe directly connected to the drum, the cross-sectional area of the short pipe should not be 1.25 times the exhaust area of all safety valves.
5. The safety valve should generally be equipped with an exhaust steam pipe, which should lead directly to a safe place and have sufficient cross-sectional area to ensure smooth exhaust. The bottom of the safety valve exhaust pipe should be equipped with a cavity as a drain pipe connected to a safe place. Valves are not allowed on the exhaust pipe and the drain pipe.