The easiest way to increase the slack channel is to thicken the valve seat, so that the valve seat hole is increased and a longer slack channel is formed. One range can delay the sudden expansion after the closed-flow diet, and play the role of shifting the damage position and keeping it away from the cover of the secret book; the other range increases the diet barrier, reduces the recovery level of the pressure, and weakens the cavitation. .
Part of the valve seat hole is conceived as a corridor type and a wave type, in order to increase the barrier and reduce the cavitation. This method is often used in the introduction of low-pressure valves in the installation and the improvement of old valves, and it is also very ineffective. 6) Change the flow direction and increase the lifespan. The open type flows toward the open position, and the main effect of cavitation and erosion is on the cover, so that the valve core joint and the valve seat cover are quickly damaged; the flow closed type flows toward the open position. After the closed position flow, cavitation and erosion effects are on a diet, the valve seat is sealed with a cover, which protects the joint between the cover and the valve core, extending the life. The valve that pretends to be a flow-open type can extend the life by 1-2 times as long as the flow direction is changed when the effect of extending the life is relatively general.
Use special materials to improve the lifespan. In order to resist cavitation (destroying shapes such as honeycomb-like dots) and erosion (streamlined small grooves), special materials that resist cavitation and erosion can be used to create diet parts. This special material includes 6YC-1, A4 steel, Stellite, cemented carbide, etc. In order to resist corrosion, materials that are more resistant to corrosion and have certain mechanical and rational functions can be used instead. This material is divided into non-metallic materials (such as rubber, tetrafluoro, ceramics, etc.) and non-metallic materials (such as Monel, Hastelloy, etc.) two categories. 8) Change the valve structure to improve the service life method Take the method of changing the valve structure or choosing a valve with a shorter life to achieve the method of improving the service life, such as the use of multi-stage valves, anti-cavitation valves, corrosion-resistant valves, etc. 2. Anti-blocking (stuck) methods for the adjustment valve often stuck or blocked (6 methods) 1) Welding slag, rust, slag, etc. in the cleaning method pipeline are formed in the diet port, guide position, and lower valve cover out-of-balance hole Blocking or jamming will cause the spool surface, the guide surface to be pulled and scratched, and the indentation to occur on the secret book cover.
At that time, it often occurred at the beginning of the year after the new commissioning system and the overhaul. This is the rarest fault. In this case, it must be disassembled and cleaned, and the slag must be removed. If the cover of the secret book is damaged, it should be ground; the bottom plug should be opened at the same time to flush out the slag falling into the lower valve cover from the misalignment hole, and For pipelines stop developing. Before putting into operation, let the adjustment valve fully open, and the medium will move for a period of time before returning to normal operation. 2) External flushing method When using general valve conditioning for some media that are easy to accumulate and contain liquid particles, they are often blocked at the diet port and guide, and external flushing gas and steam can be connected to the bottom plug of the lower valve cover. When the valve is blocked or stuck, open the external gas or steam marine valve to realize the development task without moving the regulating valve, so that the valve can operate normally.
3) Ballistic filter installation method For small-diameter conditioning valves, especially ultra-small flow conditioning valves, the diet gap is extremely small, and there is no small slag in the medium. In case of blockage in this situation, it is best to place a filter on the ballistic suit in front of the valve to ensure the successful passage of the medium. The adjustment valve with the positioner application, the positioner function has no abnormality, and the blockage of the airway diet port is the most common problem. Therefore, when working with a positioner, it is necessary to solve the air source. The generally adopted method is to install an air filter and pressure reducing valve in the air source pipeline in front of the positioner. Welding slag and rust that have been washed away have no problems such as blockage and jamming, so you can switch to diet parts with a large diet gap - the valve core and sleeve with the diet area of opening and closing the mouth. If the diet area is concentrated rather than distributed in a circle, the problem can be easily eliminated.