Boiler safety valve installation requirements
Safety valve installation shall meet the following requirements
（l）Rated evaporation is greater than 0.5t / h boiler, at least with the installation of two safety valves: Rated evaporation is less than or equal to 0.5t / h boiler, at least install one safety valve. It can be divided into economizer exit, the steam superheater outlet must install safety valve.
（2）Safety valve should be mounted vertically in the pot, box top location. Between the safety valve and the drum or header, it shall not be equipped with gaining steam outlet pipes and valves.
（3）Lever-type safety valve should have preventing heavy hammer self-moving devices and limit leverage deviant lead frame, spring type safety valve should have enhance grip and preventing screwing adjust bolt device.
（4）For the rated steam pressure of less than or equal to 3.82MPa boiler, safety valve throat diameter should not less than 25mm: For the rated steam pressure that is greater than 3.82MPa, safety valve throat diameter should not less than 20mm.
（5）Safety valve connects with the boiler connecting pipe, its cross-sectional area should not less than the safety valve inlet cross-sectional area. If several safety valves are installed together with the drum in a pipe directly connected to the short tube, short tube channel cross-sectional area should not less than 1.25 times of all exhaust safety valve area.
（6）Safety valve should normally be installed in exhaust pipe, exhaust pipe should be through a safe place, and with sufficient cross-sectional area to ensure the smooth flow of exhaust steam. At the bottom of safety valve exhaust pipe should have drain pipe that connects to a safe place, it is not allowed to install valve in the exhaust pipes and water pipes.
