Abstract: According to the principle and form of high-rise building water supply zone, the use of pressure reducing valve is proposed. According to the performance and working principle of hydraulic control valve, combined with engineering examples, the application of hydraulic control valve in the fire water supply of high-rise buildings is expounded. Keywords: fire water pressure reducing valve high-rise building into the 20th century since the 90s, with the rapid development of economic construction, improve people's living standards, high-rise buildings in large cities is a lot of construction. Building water supply and drainage technology as part of the construction technology, has also been rapid development, new materials, new equipment, new technology has been widely used. In the high-rise building water division, the valve is widely used at the same time, also experienced a spring decompression network - proportional valve - hydraulic control valve three development process. The following only on high-rise building fire water supply system partition hydraulic control valve applications published a superficial view. 1 high-rise building fire water district High-rise building fire water district should be based on the building height, pipe and fire equipment, location and project cost and other factors. In addition to reducing the pressure in the tube pressure exceeds its working pressure. But also to avoid the formation of water hammer noise and vibration, while not causing the lower part of the building fire water pressure is too large, inconvenient to use and inflow exceeding the standard. At the same time also taking into account the fire hydrant and the pressure of Pneumatic steel pipe allowable value, China's "high regulation" provides: the lowest hydrant fire hydrant water at the maximum hydrostatic pressure should not exceed 0.9MPa; "Spray" specification: automatic spray The working pressure of water system pipe network should not exceed 1.2MPa. There are three basic forms of fire water division: parallel division, series division, an increase of decompression zone (pressure relief valve zone). The advantages and disadvantages of various district water supply as shown in Table 1. 2 hydraulic control valve working principle and performance hydraulic control valve is based on the hydraulic control valve. So briefly describe the hydraulic control valve. As the name suggests, hydraulic control valve is the use of water pipe network to control the valve opening, closing and opening degree of the valve. Hydraulic control valve is composed of a main valve and its external needle valve, pilot valve and so on. Depending on the purpose of use, functions and places, can evolve into a remote control float valve, water level valve, pressure relief valve, relief valve, slow closing check valve. Its action principle is as follows: For hydraulic control valve, the pressure acting on the valve is P1S1. P1 is the water pressure before the valve, S1 is the water pressure on the valve before the valve area; role in the valve after the pressure P2S2 + Fs, where P2 is the valve after the water pressure, S2 valve pressure after the valve on the role of the area, FS The spring force acting on the valve disc. (1) fully closed state: When the inlet side of the main valve into the body and control room (when the needle valve is open), the main valve outside the ball valve closed. At this moment, the pressure in front of the valve and control room is the same, namely P1S1 = P2S2. Under spring action, the valve is closed. (2) fully open state: When the main valve inlet flow can not enter the control room (at this time the needle valve is closed), the main valve outside the ball valve open. There P1> P, P1S1> P2S2 + Fs, the role of pressure in the water, the valve opens. (3) Floating state: adjust the opening of the ball outside the main valve so that flow through the needle valve and ball valve to achieve balance. There P1S1 = P2S2 + F2, when the main valve is in a floating state. When the valve on the main valve to decompression pilot valve, and decompression pilot valve connected to the back of the main valve, put the hydraulic control valve into a hydraulically tied valve. Hydraulic control decompression room that is decompression pilot valve sensing sensing valve back pressure and control the main valve, to achieve the purpose of decompression. When the decompression pilot valve senses the downstream pressure is lower than the set value, immediately adjust the pressure to release the main valve control chamber to make the valve flap moderately open; when the decompression guide detects the downstream end pressure reaches or exceeds the set Value, began to make the main valve control room pressure makes the valve opening smaller or closed. From the principle of hydraulic control valve can be seen its excellent performance: It can be at any time according to the needs of the ink field to make appropriate adjustments to the decompression ratio, free from the body's own restrictions. The pressure at the back of the valve remains constant and will not change as the pressure on the front of the valve changes. When the valve back-end flow changes, the word can be whole valve will not flow underflow or valve back-end pressure to reduce the situation.