Ningbo Zhanyue Hydraulic is here to explain the performance and function of throttle valve:

Throttle valve is a valve that controls fluid flow by changing the throttle section or throttle length. If the throttle valve and the check valve are connected in series, they can be combined into a check valve for throttling. The throttle valve and one-way throttle valve are simple flow control valves. In the hydraulic system of the quantitative pump, the throttle valve and the overflow valve cooperate to form three types of throttle speed regulation systems, namely, the inlet throttle speed regulation system, the return throttle speed regulation system and the bypass throttle speed regulation system. The throttle valve has no flow negative feedback function and cannot compensate for the speed instability caused by the load change. It is generally only used in situations where the load change is not large or the speed stability is not required.

Performance requirements for throttle valve:

·The flow adjustment range is large, and the flow - pressure difference changes smoothly.

·The internal leakage is small. If there is an external leakage, the external leakage is also small.

The shape and structure of throttle valve is not different from that of stop valve, but the shape of their opening and closing parts is different. The opening and closing parts of the throttle valve are mostly conical streamline, through which the flow and pressure can be adjusted by changing the sectional area of the channel. The throttle valve is used to reduce the medium pressure in case of great pressure drop.

The medium flow rate between the throttle disc and the valve seat is very high, which causes the surface of these parts to be damaged quickly - that is, the so-called cavitation phenomenon. In order to minimize the impact of cavitation, the valve disc is made of cavitation resistant material (made of alloy steel) and made of a streamlined cone with a tip angle of 140~180, which can also make the valve disc have a large opening height, and throttling under a small gap is generally not recommended.

Because the flow of the throttle valve is not only dependent on the size of the throttle area, but also related to the pressure difference before and after the throttle, and the valve stiffness is small, it is only applicable to the situation where the load change of the actuator is small and the speed stability requirement is not high.

For throttle speed control system with large load variation of actuator and high requirements for speed stability, pressure compensation must be carried out for throttle valve to keep the pressure difference before and after throttle valve unchanged, so as to achieve flow stability.