How to Distinguish Relief Valve from Overflow Valve?

The functions of relief valve and overflow valve

 

The function of overflow valve is to prevent system overload and ensure safety; while the role of the relief valve is to reduce the system pressure with oil filled pressure gauge under the premise of ensuring that the system is not loaded. We can say that the overflow valve works passively, while the relief valve works actively. In addition, there are three differences:

 

1. The relief valve shall keep the pressure at the outlet unchanged, while the overflow value shall keep the pressure at the inlet unchanged.

 

2. In the absence of work, the relief valve’s import and export can interchange, while overflow valve’s are blocked;

 

3. In the non-working state, the mouth of relief valve is open, while the overflow valve’s is normally closed.

 

 

The differences between relief valve and overflow valve

 

The most important difference is that the overflow valve is a pressure control valve, mainly used to control the system pressure, but also play the role of unloading; the relief valve is a pressure regulating valve that makes the valve outlet pressure lower than the inlet pressure.

 

Relief valve is mainly used to reduce the pressure of a branch of the hydraulic power transmission system so that the branch pressure is lower than the main oil pressure and stable. The relief valve is also closed, as is the overflow valve, within the range of the set pressure, which measures through the pressure gauge ball valve. However, as the system pressure rises and reaches the pressure set by the pressure reducing valve (shown on digital pressure indicator), the relief valve opens and part of the oil will pass through it and return to the tank (at this time, the oil with a certain pressure will return to the tank and the oil temperature of the tank will rise). The relief valve plays the role of reducing pressure and stabilizing pressure on the branch. The overflow valve is different, it installed at the outlet of hydraulic pump and hydraulic pump adapter, which will ensure the overall pressure stability of the system and will not overpressure, so the overflow valve has safety, pressure regulation and pressure regulation and other functions.

 

Overflow valve in parallel with the oil pressure tester in the system of the branch plays the role of pressure regulating, stabilizing and pressure reducing, while the relief valve in series in a certain road plays the role of reducing pressure and maintaining the pressure of this branch. The overflow valve is normally closed and only operates when the system overpressure. The relief valve is always open; oil through the narrow channel will play a role in reducing pressure. In hydraulic mechanical transmission, the overflow valve controls the inlet pressure, while the relief valve controls the outlet pressure.

 

 

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 relief valve and overflow valve.