Boiler water temperature control valve can be used for large and medium-sized generating units, the main steam boiler and reheat steam temperature control of the water required for the cooling water flow rate, it is one of the key power plant valve. stn water regulating valve is a kind of anti-cavitation multi-stage throttling control valve, also known as high-pressure regulating valve, which is a novel structure of the control valve. Cascade water reducing valve has the following advantages: 1. Fluid step-down, the fluid direction is constantly changing, stn water regulating valve with cascade structure, the fluid through the tortuous passage, the purpose is to reduce the flow of energy consumption, Prevent liquid cavitation. Increase the flow resistance, control the flow rate to prevent cavitation damage. Allow pressure drop 25mpa. 2. Multi-level throttling: 4 throttling at high flow rate, 5 throttling at low flow rate, to reduce fluid erosion on the spool surface. 3. Throttling surface and the sealing surface separately, the valve core and the valve sleeve surface hardening treatment, the hardness reaches hrc70 or so, close tight, long life. 4. There is a big gap on the surface of the valve core. The fluid contains solid particles such as 2 ~ 3mm welding slag and the valve core will not be stuck and the movement is flexible. 5 flow adjustment features good adjustment range (about 60 ~ 70%). The control valve is a patented product, our patent registration number is no.15739, many power plants have successfully used this multi-stage throttling control valve.