Hydraulic control valve is composed of a main valve and its external needle valve and pilot valve. Hydraulic control valve is a general term for a series of multi-purpose control and safety valves. Mainly include: 1: remote control float valve; 2: pressure reducing valve; 3: slow closing check valve; 4: relief valve; 5: holding pressure valve and so on. Their main features are: the role of the way to use their own media pressure and hydraulic system operation, and automatic control, accurate action, reliable performance, can be widely used in life production and fire water supply pipe system control and safety role. However, the hydraulic control valve in the project, there are still some errors, such as the valve conditions, valve design requirements, installation points, for this reason, this paper to CECS standard "hydraulic control valve application design rules" Draft) as the basis, combined with my experience to elaborate on the various aspects of the problem. Hydraulic control valve design selection points (1) engineering application of the hydraulic control valve is tested by the manufacturer, a variety of labels complete, technical information to meet the requirements of the product. (2) According to the functional requirements, select the type of valve, and then determine the valve body and sealing parts of the valve according to the pipeline transportation media, temperature, building standards and the main requirements of the owners. Common body materials are cast iron, copper and iron, copper, plastic and so on. Common sealing surface and lining materials are copper alloy, plastic, steel, hard alloy, rubber and so on. Valve body material should be matched with the pipe material. (3) The nominal pressure of the valve is 0.6, 1.0, 1.6, 2.5 and 4.0MPa and other different levels, pipeline transport medium, the working pressure should be less than the nominal valve pressure value. (4) The hydraulic control valve in the project should be provided with enough space for management, operation, installation and maintenance, and should meet the requirements of the pipeline on the valve. (5) When the pipe is flanged, a flanged hydraulic control valve should be used. When the pipe is grooved, a grooved hydraulic control valve should be used. (6) Hydraulic control valve should be set in the medium flow of one-way pipeline. (7) The direction of the arrow on the main valve of the hydraulic control valve must be consistent with that of the piping system. (8) then the hydraulic control valve pipe should not be blocked, gas resistance phenomenon. The highest position in the pipe network should be set automatically save gas exhaust valve. (9) When the valve is installed horizontally, the bonnet and stem should face upward. Vertical installation, the valve cover, stem should be outward. (10) The valve should be installed before the intensity and tightness test. (11) The strength and tightness of the valve shall meet the following requirements. A, the valve strength test pressure of 1.5 times the nominal pressure; B, valve tightness test pressure of 1.5 times the nominal pressure; C, the test pressure should remain unchanged during the test duration, and the shell packing and valve seal No leakage; D, valve test duration according to the above table. Valve Test Duration Nominal diameter DN (mm) Minimum test duration (S) Tightness test Strength test Metal seal Nonmetallic seal ≤ 50 15 15 15 65 ~ 200 30 15 60 250 ~ 450 60 30 180
Metallic Powder Coating Co., Ltd. , http://www.nsralcolour.com