(1) For boilers with a rated evaporation capacity greater than 0.5t/h, at least two
Throttle Valve shall be installed; for boilers with a rated evaporation capacity less than or equal to 0.5t/h, at least one
Universal Valve shall be installed. Throttle Valve must be installed at the outlet of the split economizer and the outlet of the steam superheater.
(2) Throttle Valve shall be installed vertically at the highest position of the boiler drum or header. No outlet pipe or valve for taking steam shall be installed between the Universal Valve and the drum or header.
(3) Throttle Valve shall have a device to prevent the weight from moving on its own and a guide to limit the lever from going off the track. Spring-type Universal Valve shall have a lifting handle and a device to prevent the adjustment screw from being turned at will.
(4) For boilers with a rated steam pressure less than or equal to 3.82MPa, the throat diameter of the Throttle Valve shall not be less than 25mm; for boilers with a rated steam pressure greater than 3.82MPa, the throat diameter of the Universal Valve shall not be less than 20mm.
(5) The cross-sectional area of the connecting pipe between the Throttle Valve and the boiler shall not be less than the inlet cross-sectional area of the Universal Valve. If several Universal Valve are installed together on a short pipe directly connected to the boiler drum, the passage cross-sectional area of the short pipe should not be less than 1.25 times the exhaust area of all Universal Valve.
(6) The Throttle Valve should generally be equipped with an exhaust pipe, which should be directly connected to a safe place and have a sufficient cross-sectional area to ensure smooth exhaust. The bottom of the exhaust pipe of the Universal Valve should be equipped with a drain pipe connected to a safe place. Valves are not allowed to be installed on the exhaust pipe and the drain pipe.
