Do You Know How Overflow Valves and Pressure Relief Valves Work?

In engineering projects, we often need to provide different negative pressures through negative pressure gauges due to different loads. If continuous pressure regulation is required, proportional pressure valves are the solution. If pressure gears are scarce and cost considerations are required, a combination of a conventional relief or relief valve and a solenoid on/off valve would be perfect in hydraulic mechanical transmission.

 

 

The structure and working principle of overflow valve

 

Overflow valve is a hydraulic pressure limit valve, in the hydraulic power transmission system mainly plays the role of constant pressure overflow, stabilizing pressure, system unloading and safety protection.

 

When the relief valve is in operation, the pressure from the oil line P is applied to the main spool. At the same time, the pressure from ball pressure gauge is exerted on the spring-loaded side of the main spool and on the ball of the pilot valve through a control path with a throttling hole. If the pressure at port P exceeds the set value of the spring, the ball will overcome the spring force by pressure gauge ball valve and cause the pilot valve to open.

 

The control oil is obtained from inside the port P through the control channel. The oil on the spring loading side of the main spool flows into the spring chamber through the control path, throttling hole and the Hydraulic Ball Valve PN500. The throttle orifice and pressure drop are generated at both ends of the main spool, so the P to T port connection channel is opened. The oil flows from Port P to Port T, and the set working pressure remains unchanged. The relief valve can be unloaded or switched at different pressures (secondary pressures) by means of oil port X.

 

 

The structure and working principle of pressure relief valve

 

Pressure relief valve is a valve that reduces the inlet pressure to a required outlet pressure by adjusting and keeps the outlet pressure stable automatically by force feedback.

 

The pressure relief valve consists of a main valve with a main valve plug and a pilot valve with a pressure regulating assembly. At the static position, the valve remains open; The oil is free to enter the oil port A from the oil port B through the main spool plug. At this point, the pressure of oil port A ACTS on the bottom side of the main spool; At the same time, it ACTS on the hydraulic ball valve in the pilot valve and ACTS on the spring loading side of the main spool through the throttling hole. Similarly, pressure is applied to the ball valve through the throttle orifice, control manifold, check valve and throttle orifice. At this point according to the setting of the spring, in the ball valve front, the oil mouth and the spring chamber-built pressure, keep the control piston in the open position.

 

Jazzy is a company specializing in the R&D, design, and development of non-standard machinery with hydraulic hose fitting and hydraulic rubber hose, based on high-performance pneumatic and hydraulic transmission system. We are also committed to offer you best overflow valves and pressure relief valves.