How it works: When the valve needs to be opened urgently, the actuator drives the valve stem to open the small valve core (pilot valve core) first, so that the pressure in the valve chamber is quickly relieved, and the small valve core keeps running to drive the large valve core to open. Such valves using advanced pilot valve structure, has the following advantages: 1. Sleeve throttling, throttling surface and the sealing surface separately, the valve main parts using special stainless steel surface hardening treatment, the hardness of HRC70 or more. Close tight, long life. STU condensate water load control valve is a special designed for condensate water system, the height plus the crisis of the hydrophobic systems and other large flow large caliber requirements of a good special sealing valve, 2. Regulating the characteristics of good, large adjustment range, the switch flexible. 3. Pilot valve structure, the valve opening force reduced by 15 times, reducing the size and cost of the implementing agencies.