Tanggu Valve Internationally, the valve is developing rapidly in the direction of miniaturization, integration, digitization, intelligence, bus and network. There is still a long way to go, and high-function valves with independent intellectual property rights are very scarce. The purpose of this paper is to find the distance between us and the world in terms of valves, clarify the policy, and reduce the distance between domestic valves and the world's advanced level as soon as possible through our efforts.

One of the faults is that the valve is blocked.

The reasons are: ① the control channel is blocked by debris (the channel is small and easy to block); ② the piston is stuck in the highest position due to rust stains; although the upper part is stressed, it cannot move down and the main channel cannot be opened. Therefore, a filter must be installed before the piston pressure reducing valve; for new equipment or a pressure reducing valve that has been out of use for a long time, it must be disassembled for inspection and cleaning.

The second problem is that the valve is straight through, which does not have a decompression effect.

The reasons are: ① the piston is stuck in a certain position (not the highest position); ② the valve handle of the main valve is stuck in a certain position (not the close position) of the guide hole of the cylinder disc; ③ the lower spring of the main valve disc is broken or failed ;④The valve handle of the pulse valve is stuck in a certain position (not the close position) in the valve seat hole, so that the piston is always under pressure; There are nicks; ⑥ The diaphragm fails due to fatigue or damage. Regarding the pressure reducing valve, it is especially important to check regularly. If any dirt or rust is found, it should be removed in time; if the piston ring is damaged, it should be replaced; if the spring fails, it should be replaced with a usable one; Coarse, use sandpaper.

Third, the pressure behind the valve cannot be adjusted. Apart from the above reasons

Also: ① the adjustment spring fails; ② the seam of the cap leaks and the pressure cannot be maintained.

This also depends on timely inspection and processing to prevent. In addition, there is a phenomenon that the pressure pulse behind the valve is shaken, which is extremely unstable. This is because the difference between the input medium and the output medium is too large, and the valve with the same valve diameter should be selected from scratch. Another reason for the unstable pressure behind the valve is the improper selection of the conditioning spring; a pressure reducing valve with a nominal pressure, there are several types of conditioning springs, for example, the nominal pressure is 16 kg/square centimeter, the conditioning spring has 1-3kg/cm2, 2-8kg/cm2, 7-11kg/cm2, if the pressure behind the valve is only 1-3kg/cm2, but the tension spring is 7-11kg/ The kind of square centimeter, the pressure behind the valve is prohibited. 2. One of the faults of the spring-loaded safety valve is the leakage of the sealing surface. The reasons are as follows: ①There is debris between the sealing surfaces; ②The sealing surface is damaged. This kind of fault should be prevented by regular maintenance. The second problem is that the activity is not high. The reasons are: ① spring fatigue; ② improper use of spring. The springs are fatigued and should undoubtedly be replaced. Improper use of the spring is a spring-type safety valve in which the user does not pay attention to the nominal pressure. There are several pressure sections, and each pressure section has a corresponding spring. For example, a safety valve with a nominal pressure of 16 kg/cm 2 uses a pressure section with a pressure of 2.5-4 kg/cm 2 and a tension spring of 10-16 kg/cm 2 is installed. Low, very inactive.

The common faults of check valve or check valve are: ① valve disc is broken; ② medium backflow. The reason that the valve disc is broken is: the pressure of the medium before and after the check valve is in a state of close balance and mutual "saw", the valve disc is often knocked against the valve seat, and some brittle materials (such as cast iron, brass, etc.) are made of The valve disc is broken. The preventive way is to use a check valve with the disc as a tough material. The reasons for the backflow of the medium are: ①The sealing surface is damaged; ②The impurities are trapped. By repairing the sealing surface and cleaning impurities, backflow can be avoided. The above description of common faults and preventive measures can only be enlightening. In actual application, other faults will also be encountered. To actively and sensitively prevent the occurrence of valve faults, the most fundamental one is to understand its structure and material. and principle of action.

Valve is a very important on-site driving equipment in industrial process control system. Its energy is convenient to win, equipment debugging is simple, and it is more and more widely used in electric power, metallurgy, petroleum, chemical industry and other industrial sectors. The valve includes two parts, the electric actuator and the regulating valve. The control accuracy is mainly determined by the control function of the valve. It can convert the control signal of the system into the angular displacement of the output shaft, the linear displacement, and control the position of the valve and other closing parts or other regulating structures. , so that the controlled medium operates according to the system requirements.