I. Brief introduction of Z41X bright rod elastic seat sealing gate valve:
The opening and closing member of the open-seat elastic seat sealing gate valve is a gate plate. The direction of movement of the gate plate is perpendicular to the fluid direction. The gate valve can only be fully opened and fully closed, and cannot be adjusted and throttled. 软密封闸阀 最常用的模式闸板阀的两个密封面形成楔形、楔形角随阀门参数而异, 通常为50, 介质温度不高时为2¡ã52'''' 。 The gate has two sealing surfaces.The most common mode of the soft-sealed gate valve is the wedge shape of the two sealing surfaces. The wedge angle varies with the valve parameters, usually 50, and 2 ¡ã 52 'when the medium temperature is not high.' ' '. The gate of the wedge gate valve can be made into a whole, called a rigid gate; it can also be made into a gate that can produce a small amount of deformation to improve its processability and make up for the deviation of the sealing surface angle during processing. The plate is called a spring gate. This type of valve should generally be installed horizontally in the pipeline.
The elastic seated gate valve is also called a lift rod gate valve (also known as an open rod gate valve). Usually, there is a trapezoidal thread on the lifting rod, and the rotary motion is changed to linear motion through the nut on the top of the valve and the guide groove on the valve body, that is, the operating torque is changed to the operating thrust. When the valve is opened, when the lift height of the gate is equal to 1: 1 of the valve diameter, the fluid channel is completely clear, but this position cannot be monitored during operation. In actual use, the apex of the valve stem is used as a mark, that is, the position where it cannot be opened, as its fully open position. 为考虑温度变化出现锁死现象, 通常在开到顶点位置上，再倒回1/2-1圈，作为全开阀门的位置。 The soft-sealed gate valve is locked in consideration of temperature changes. It is usually opened to the top position, and then turned back to 1 / 2-1 circle as the fully open valve position. Therefore, the fully open position of the valve is determined by the position of the shutter (ie, stroke).
General requirements for Z41X open rod spring seat gate valve:
1.1 The specification and category of the open-seat elastic seated gate valve shall meet the requirements of the pipeline design documents.
1.2 The type of elastic seated gate valve should indicate the national standard number requirements. If it is an enterprise standard, the relevant description of the model should be indicated.
1.3 The working pressure of the dark-stem elastic seated gate valve must be ≥ the working pressure of the pipeline. Without affecting the price, the working pressure of the valve should be greater than the actual working pressure of the pipeline; One side should be able to withstand 1.1 times the valve's working pressure without leakage; when the valve is open, the valve body should be able to withstand the requirement of double the valve's working pressure.
1.4 The manufacturing standard of the open-seat elastic seated gate valve should indicate the national standard number on which it is based. If it is an enterprise standard, the enterprise contract should be attached to the procurement contract.
、 Z41X明杆弹性座封闸阀标质： Third , Z41X open rod spring seat gate valve standard:
2.1 The material of the valve body should be nodular cast iron, cast steel, stainless steel, 316L, and indicate the grade and actual physical and chemical test data of cast iron.
2.2 Valve stem material, striving for stainless steel stem (2CR13), large-caliber valve should also be stainless steel inlaid stem.
2.3 Nut material, using cast aluminum brass or cast aluminum bronze, and the hardness and strength are greater than the valve stem.
2.4 Stem bushing material, its hardness and strength should not be greater than the stem, and no electrochemical corrosion with the stem and valve body under water immersion.
2.5 Material of sealing surface
① There are different types of open seat elastic seated gate valves, different sealing methods and material requirements;
② For ordinary wedge gate valves, the material, fixing method and grinding method of the copper ring should be specified;
③Physical, chemical and hygienic test data of soft-sealed gate valves and valve lining rubber materials;
2.6 Valve shaft packing
①Because of the dark rod elastic seated gate valve in the pipe network, it is usually opened and closed infrequently. It is required that the packing does not move for several years, the packing does not age, and the sealing effect is maintained for a long time;
② Valve shaft packing should also have good sealing effect when subjected to frequent opening and closing;
③ In view of the above requirements, the valve shaft packing strives not to change for a lifetime or for more than ten years;
④ If the packing needs to be replaced, the design of the pneumatic valve should consider the measures to be replaced under the condition of water pressure.
、 Z41X明杆弹性座封闸阀的操作机构： Fourth , the operating mechanism of Z41X open rod spring seat gate valve:
3.1 The opening and closing direction of the elastic seat gate valve should be closed clockwise.
3.2 Due to the pneumatic valve in the pipe network, it is often manually opened and closed, and the number of opening and closing revolutions should not be too much, that is, the large-caliber valve should also be within 200-600 revolutions.
3.3 In order to facilitate the opening and closing operation of one person, the maximum opening and closing torque should be 240N-m under the condition of pipeline pressure.
3.4 The opening and closing operation end of the concealed elastic seat sealing gate valve should be square tenon, and the size is standardized, and it faces the ground, so that people can directly operate from the ground. Valves with roulette are not suitable for underground pipe networks.
3.5 Opening and closing degree display panel of bright-seat elastic seat gate valve
① The scale of the opening and closing degree of the bright-seat elastic seat gate valve should be cast on the gearbox cover or the shell of the display panel after the direction is changed, all facing the ground, and the scale is brushed with fluorescent powder to show eye-catching;
② The material of the indicator needle can be made of stainless steel under better management; otherwise, it is painted steel, and it should not be made of aluminum skin;
③ The indication needle is eye-catching and firmly fixed. Once the opening and closing adjustment is accurate, it should be locked with rivets.
3.6 If the flexible seat sealing gate valve is buried deeper, when the distance between the operating mechanism and the display panel is 1.5m from the ground, an extension rod facility shall be provided and fixed firmly so that people can observe and operate from the ground. In other words, the opening and closing of valves in the pipeline network is not suitable for downhole operations.
V. Performance test of Z41X bright rod elastic seat sealing gate valve:
4.1 When a valve of a certain specification is manufactured in batches, an authoritative institution should be entrusted to perform the following performance testing:
① Opening and closing torque of the valve under working pressure;
② Under the condition of working pressure, it can ensure that the valve is closed tightly for continuous opening and closing times;
③Detection of flow resistance coefficient of valve under pipeline water delivery condition.
4.2 The valve should be tested as follows before leaving the factory:
① When the valve is open, the valve body should withstand the internal pressure detection of twice the valve's working pressure value;
② Under the closed condition of the valve, the two sides bear 1.1 times the valve working pressure value, and there is no leakage; however, the leakage value of the metal-sealed butterfly valve is not greater than the relevant requirements.
Z41X明杆弹性座封闸阀 的内外防腐： Six, the inner and outer anticorrosion of Z41X bright-stem elastic seat sealing gate valve :
5.1 Inside and outside the valve body (including the variable speed transmission case), firstly, shot blasting and sand removal should be performed, and electrostatic powder sprayed non-toxic epoxy resin should be used, with a thickness of more than 0.3mm. When it is difficult to electrostatically spray non-toxic epoxy resin for oversized valves, similar non-toxic epoxy paint should also be applied by brushing and spraying.
5.2 The valve body and various parts of the valve plate require full corrosion protection. On the one hand, it will not rust when immersed in water, and it will not cause electrochemical corrosion between the two metals.
5.3 The hygienic requirements of anticorrosive epoxy resin or paint in the valve body shall have the test report of the corresponding authority. Chemical and physical properties should also meet relevant requirements.
Seven, Z41X open rod spring seat gate valve packing and transportation:
6.1 Light blocking plates should be provided on both sides of the valve for solid sealing.
6.2 Medium and small caliber valves should be tied with straw ropes and transported in containers.
6.3 Large-caliber valves are also provided with a simple solid wood frame to prevent damage during transportation.
Eight, Z41X Ming rod elastic seat sealing gate valve factory instructions:
Pneumatic gate valve is equipment, and the following relevant data should be marked in the factory instruction:
Valve specifications; model; working pressure; manufacturing standards; valve body material; valve stem material; sealing material; valve shaft packing material; valve shaft sleeve material; internal and external anticorrosive material; operation starting direction; number of revolutions; opening and closing under working pressure Moment; manufacturer's name; date of manufacture; number of manufacture; weight; diameter, number of holes, center distance of connecting flanges; the overall length, width, and height control dimensions are shown graphically; valve flow resistance coefficient; effective Opening and closing times; relevant data for valve factory inspection and precautions for installation and maintenance.
Z41X明杆弹性座封闸阀 出材料： Nine, Z41X open rod spring seat gate valve material:
Body: cast iron, ductile iron, carbon steel
Valve cover: cast iron, ductile iron, carbon steel
Bonnet bracket: carbon steel
Handwheel: cast iron, forged steel
Dash: Ductile iron, carbon steel core fully covered with EPDM vulcanized rubber, new brass wedge nut with anti-detachment
Fixed pin: 1Cr18Ni9
Stem sealing ring: PTFE (polytetrafluoroethylene), NBRO ring
Bonnet nut: Dezincification resistant brass
Bonnet gasket: EPDM rubber
Bonnet bolt: galvanized steel grade 8.8
Coating: thermal spray epoxy coating
Z41X明杆弹性座封闸阀 故障排除方法： Ten, Z41X open rod spring seat gate valve troubleshooting method:
1 Leak at soft packing gate valve packing
(1) The packing gland is too loose, and the nut for packing gland can be evenly tightened.
(2) The number of packing rings is not enough. The packing should be increased.
(3) The packing should be replaced with new packing due to long-term use or improper storage. When replacing, the joints between the rings should be staggered and staggered by 1200.
2 Between soft seal gate valve gate and seat sealing surface
(1) There is dirt between the sealing surfaces, which can be washed away to eliminate it.
(2) If the sealing surface is damaged, it should be reground. If necessary, it can be re-surfacing and processed. The ground sealing surface must be flat and its roughness must not be less than 0.4.
3 The leakage nut at the joint of the soft-sealed gate valve body and bonnet is not tightened tightly or unevenly, and it can be readjusted.
(1) Any damage (straight grooves or groove marks) on the flange sealing surface should be corrected.
(2) The gasket is damaged. Replace it with a new one.
4 Soft sealing gate valve stem transmission is not flexible
(1) The packing is too tight, and the nuts on the packing gland should be loosened properly.
(2) The packing gland is not in the correct position, so that the valve stem is stuck, and the nuts on the packing gland should be evenly rotated to restore the gland to its normal position.
(3) The threads on the stem and stem nut are damaged and should be removed after disassembly.