The performance requirements for throttle valves are:
• The Flow regulation range is large, the flow rate one pressure difference change is smooth;
• The amount of internal leakage is small, if there is an external leakage oil outlet, the amount of external leakage should also be small;
• Small adjustment torque and sensitive movement. The shape structure of the throttle valve (Choke valve) is no different from the cutoff valve, except that the shape of their opening and closing parts is different. Throttle valve Opening and closing parts are mostly conical streamlined, through which to change the channel cross-sectional area to achieve the regulation of flow and pressure.
The throttle valve is used to reduce the pressure of the medium under the condition of great pressure drop. The medium flow rate between the throttle disc and the seat is very large, so that the surface of these parts is quickly damaged, that is, the so-called cavitation phenomenon.
In order to minimize the impact of cavitation, the disc uses corrosion-resistant materials (alloy steel) and makes a streamlined cone with a top angle of 140~180, which also allows the disc to have a larger opening height, which is generally not recommended for throttling under small crevices.