600X electric control valves should be installed horizontally. When installed horizontally, the valve cover should be facing upward. There should be drainage facilities behind the pressure reducing valve of the fire water supply system. When the automatic sprinkler fire extinguishing system needs to reduce pressure, the pressure reducing valve should be set in front of the alarm valve (along the water flow direction). The pressure reducing valve set with a single alarm valve does not need to be equipped with a factory pressure reducing valve; the pressure reducing valve set with multiple alarm valves should be equipped with a factory pressure reducing valve. The pressure reducing valve used for hot water supply projects should use hot water type pressure reducing valves.
For hot water supply projects using the main pipe main pipe circulation method (semi-circulation method), the pressure reducing valve setting requirements should be the same as those for cold water projects; for hot water supply projects using the riser circulation method (full circulation method), the pressure reducing valve setting should prevent the damage of hot water circulation, and the pressure of each partition return pipe should be balanced at the confluence point.
