Automatic Control Valves Hydraulic Check Valve BTA 811
It permits the main valve to be fully open when inlet pressure exceeds outlet pressure in the normal direction and main valve close drip-tight on reverse flow. Opening and closing speeds are separately adjustable.
The Valve Operates on the differential between two pressure : upstream or inlet pressure acting under the seat of the valve , and downstream or outlet pressure acting on the diaphragm via single hydraulic line. When upstream pressure is greater of the forward flow , the valve opens at an adjustable rate to allow flow. When downstream pressure is greater , the valve is forced fully closed.