Pressure release valve for pumps

摘要

An airless hydraulic diaphragm paint pump having a pumping chamber subdivided by a diaphragm into pumping fluid and pump fluid subchambers with an inlet from a pump fluids storage and an outlet to a pumped fluid utilizer such as a paint spray gun. A bypass port is provided for returning pumped fluid to the source at a low pressure. A pressure release valve in communication with both the outlet and the bypass port is effective to allow bypassing the pumped fluid directly back to the source and to bleed the line between the pumped fluid utilizer and the pump. The valve is actuated by a solenoid actuator and is opened when the pump drive is terminated or manually or in the event of an excessive high pressure.