What requirements should be met in installation of Safety Valve for Gas-fired Hot Water
Installation of Safety Valve for Gas-fired Hot Water Boiler
For gas heating boilers with rated evaporation greater than 0.5t/h, at least two safety valves shall be installed: gas heating boilers with rated evaporation less than or equal to 0.5t/h, and at least one safety valve. Divisible
Safety valves must be installed at the outlet of type economizer and steam superheater.
(2) the gas hot water boiler safety valve should be installed vertically in the highest position of the boiler dealer and header. Between the safety valve and the pot or header, there shall be no outlet pipes and valves for the use of steam.
(3) the lever safety valve should have a device to prevent the weight hammer from moving by itself and a guide frame to limit the lever from crossing the rail, and the spring type safety valve should have a lifting handle and a device to prevent the adjustment screw from being twisted casually.
(4) for gas heating boilers with rated steam pressure less than or equal to 3.82MPa, the throat diameter of safety valve should not be less than 25mm, and for gas heating boilers with rated steam pressure greater than 3.82MPa, the throat diameter of safety valve should not be less than 20mm.
(5) the cross section area of the connection pipe between the safety valve and the gas heating boiler shall be not less than the inlet cross section area of the safety valve. If several safety valves are installed on a short pipe directly connected to the pot tube, the cross section area of the short pipe should not be 1. 25 times of the exhaust area of all safety valves.
(6) the safety valve should be installed with exhaust pipe, which should go straight to the safe place and have enough cross section area to ensure the smooth flow of exhaust steam. The bottom of the safety valve exhaust pipe shall be equipped with a drain pipe connected to a safe place, and valves shall not be installed on neither the exhaust pipe nor the drain pipe.
