Water Control Valve. su kontrol valfi.

grabcad

Control valves are a set of valves that operate in special ways. There are three fundamental types of control valves: backflow control, air control, and altitude. A backflow control valve is a control valve designed to prevent water from flowing in the reverse direction. Essentially, backflow control valves allow flow in only one direction—the normal flow dirrection. Backflow control valves are open in the direction of normal flow and closed with the reversal of flow. Backflow control valves are commonly found near pump stations and reservoirs. Air control valves are control valves that are used to either relieve the system of trapped air or vacuums that may develop. Finally, an altitude valve is a control valve that controls water flow into a tower when the water level drops below a threshold. Altitude valves automatically shut off water flow when the water level in an elevated tank (or tower) reaches a preset elevation. A pressure reducing valve is a system valve with a horizontal disk for automatically reducing water pressures to a preset value. A pressure relief valve is a system valve that opens automatically when water pressure reaches a preset limit to relieve stress on a pipeline. Pressure relief valves are used to protect against rapid increases in pressure (i.e., water hammer). A pressure sustaining valve is a system valve that automatically sustains water pressures at a preset value. A pressure sustaining valve is similar to a pressure reducing valve but governs the pressure on the upstream rather than the downstream flow.