Balanced fluid pressure relief valve - has pressure chamber round plunger inlet end connected by throttle to outlet

摘要

The balanced pressure relief valve for fluids, has a spring-loaded plunger acting as a pressure balancer and with a throttle passage running through it. A pilot valve has inlet and outlet connected respectively to the plunger spring chamber and to the valve outlet. Plunger and pilot valve plug have a common closing spring, the end face of the plunger on the inlet side being of smaller area than at the spring chamber side. A pressure chamber encloses the plunger between the inlet end face and a face forming a step. This chamber is connected by a throttle to the valve outlet. The size of the step face and the flow resistance of the throttle are such that the apparent spring rate is small or negligible.