For this purpose, draft articles have been drafted to discuss whether the changes can be made within the industry and arouse the concern of all enterprises in this respect and to improve their work in this area.1. The specifications and categories of valves should comply with the requirements of the pipeline design documents. 1.2; valve model should be marked on the basis of GB number requirements. If the enterprise standard, should indicate the relevant description of the model. ? 1.3; Valve working pressure, working pressure ≥ pipe, without affecting the price under the premise of the valve can withstand the working pressure should be greater than the actual pipeline pressure; valve closed condition on either side should be able to withstand 1.1 times the valve Working pressure value, without leakage; valve open condition, the valve body should be able to withstand the pressure twice the valve requirements. 1.4; valve manufacturing standards should be based on the national standard number, if the enterprise standard, the procurement contract should be attached to the enterprise Valve 2 Material 2.1 valve material, gray cast iron pipe gradually not recommended, the valve body material should be mainly ductile iron, and indicate the actual physical and chemical testing of castings and castings. 2.2; stem material, and strive to stainless steel stem (2CR13), large-diameter valve should also be stainless steel embedded valve stem. 2.3; nut material, the use of cast aluminum brass or cast aluminum bronze, and the hardness and strength are greater than the stem 2.4; stem bushing material, the hardness and strength should not be greater than the stem, and in the water soaking conditions Valve stem, body does not form electrochemical corrosion. 2.5; The material of the sealing surface ①The types of valves are different, the sealing method and material requirements are different; ② The material, fixing method and grinding method of common wedge gate valve and copper ring should be specified; ③ The soft sealing gate valve and valve lining material Of the physical and chemical and health testing data; ④ butterfly valve should be marked on the sealing material on the valve body and sealing material on the disc; their physical and chemical testing data, especially the rubber hygiene requirements, anti-aging properties, wear resistance; NBR and EPDM rubber, etc., is strictly prohibited mixed with recycled rubber. ? 2.6; valve shaft packing? ①due to the valve in the pipe network, usually not frequent opening and closing, requiring filler inactivity within a few years, the filler is not aging, long-term sealing effect; ② valve shaft filler should bear frequent In view of the above requirements, the valve shaft packing for life or do not change for more than ten years;? Filler for replacement, the valve should be designed to consider the situation under pressure to replace the measures . 3? Transmission gear box 3.1; Cabinet material and internal and external corrosion requirements and the same principle of the valve body. 3.2; Enclosure should be sealed, the box assembly can withstand 3 meters of water column status immersion. 3.3 Box opening and closing limit device, the adjustment nut should be in the box. 3.4. Transmission structure design is reasonable, when opening and closing can only drive the valve shaft to rotate, not to make it move up and down, transmission parts bite moderately, do not produce separation and slipping with load hoist. ? 3.5; Variable speed transmission box and the shaft seal can not be connected into a whole without leakage. 3.6; no debris inside the box, the gear occlusion should have grease protection. ? 4? Valve operating mechanism 4. Opening and closing the valve operation direction, should be closed clockwise. ? 4.2. As the network of valves, often manual opening and closing, opening and closing speed should not be too much, that is, large-diameter valves should also be within 200-600 turn. ? 4.3; In order to facilitate a person's opening and closing operations, in the plumbing conditions, the maximum opening and closing torque should be 240m-m. 4.4; Valve opening and closing operation end should be square tenon, and size standardization, and facing the ground, so that people from the ground can be directly manipulated. Valves with wheels are not suitable for underground pipe networks. ? 4.5; degree of opening and closing of the valve display ①valve opening and closing of the scale line should be cast in the gearbox cover or switch the direction of the display panel after the shell, all toward the ground, the scale brush phosphor to show Eye-catching;? ② indicate the needle plate material in the management of better use of stainless steel plate, otherwise painted steel, do not use aluminum production;? ③ instructions needle needle eye-catching, fixed firmly, once the opening and closing adjustment is accurate , Should be locked with rivets 4.6; If the valve is buried deep, the operating mechanism and the display panel from the ground distance ≥ 1? 5m, should be equipped with additional rod facilities, and fixed firmly, so that people from the ground to observe and operate. In other words, pipe network valve opening and closing operation, should not go down to work. ? 5? Valve performance testing? 5.1; valve specifications of a batch manufacturing, authoritative agencies should be entrusted to perform the following performance testing :??? valve opening and closing torque in the working conditions;? ② working pressure conditions, Can ensure that the valve closed tight open and close the number of times; ③ valve in the pipeline water flow resistance coefficient of detection. 5.2; The valve should be tested at the factory as follows: ①When the valve is in the open condition, the valve body shall withstand the internal pressure twice the pressure value of the valve; ② When the valve is closed, the valve shall withstand 1 to 1 times Valve work pressure value, no leakage; but the metal seal butterfly valve, the leakage value is not greater than the relevant requirements 6? Valve corrosion inside and outside? 6.1; body (including variable speed transmission box) inside and outside, Rust, and strive to electrostatic spray powder non-toxic epoxy resin, the thickness of 0? 3mm above. Extra-large valve electrostatic spraying non-toxic epoxy resin difficulties, should also be brushing, spraying similar non-toxic epoxy paint. 6.2; All parts of the valve body and the valve plate require full corrosion protection. On the one hand, it will not corrode in the water and will not produce electrochemical corrosion between the two metals. On the other hand, the smoothness of the surface will reduce the over water resistance. 6.3; Anticorrosion epoxy resin or paint the body of the health requirements, there should be the corresponding authority of the test report. Chemical and physical properties should also meet the relevant requirements. ? 7? Valve packaging and transportation? 7.1; should be set on both sides of the valve light blocking plate solid seal. ? Small and medium-sized valves should be tied with straw and transported by container. 7.3 Large diameter valve also has a simple wooden frame retention packaging, in order to avoid damage during transport 8? Valve factory manual? Valve is equipment, the factory manual should be marked with the following relevant data:? Valve Specifications; Model; Working pressure ; Manufacturing standards; body material ;; stem material; sealing material; valve shaft packing material; stem bushing material; inside and outside the anti-corrosion material; operation start direction; revolutions; ; Factory date; Factory number: Weight; Connecting the flange aperture, the number of holes, the center hole pitch to indicate the overall length, width and height of the control size; effective opening and closing times the valve flow resistance coefficient; Related data and installation, maintenance precautions and so on.