High and low pressure switch valve is the protection element of high pressure system of high pressure foaming machine, which protects the mixing head through high pressure bypass to ensure the normal operation of high pressure system: the switch valve is equipped with imported actuator, and the valve body is made of high-quality alloy material, which is durable. Integrated with German pneumatic technology, it is suitable for various types of high-pressure foaming machine. The pneumatic high-pressure and low-pressure change-over valve adopts non sealing design, which will not produce internal leakage and ensure the stability of flow. Automatic switching between high and low pressure can reduce equipment wear and improve the service life of foaming equipment. Features: the imported fork type pneumatic actuator has the characteristics of large torque and fast action, which is especially suitable for the viscous fluid characteristics of polyurethane. It can effectively solve the problems of slow opening, blocking and easy damage of the sealing ring of the switching valve. It is durable and rapid in pressure relief.