The pneumatic throttle control valve controls fluid flow by changing the throttle section or throttle length. The parallel connection of the throttle valve and one-way valve can be combined into a one-way throttle valve. Throttle valves and one-way throttle valves are simple flow control valves. In the hydraulic system of a quantitative pump, throttle valves and relief valves cooperate to form three throttle speed control systems, namely, intake throttle speed control system, return throttle speed control system and bypass throttle speed control system. Throttle valves have no flow negative feedback function and can not compensate for the speed instability caused by load changes. They are generally only used in situations where the load changes little or the speed stability requirements are not high.
