BKV BDV Model Valves are hydraulically operated control valves that reduce higher upstream pressure in the water network into a preset desired lower constant downstream pressure, and maintain it constant, regardless of fluctuating demand or varying upstream pressure. They are simple and reliable globe valves with full bore hydrodynamic body providing an unobstructed flow path and superior performance. When there is no flow in the system, it closes by itself automatically, and whenever the valve upstream pressure value decreases below adjusted downstream pressure value, it opens fully by itself. In cases, the valve downstream pressure value increases above adjusted downstream pressure value, it closes fully by itself.