Flange and welding are two ways of connecting the gate valve. They are determined according to different pressure conditions. In general, a flanged gate valve is used when the pipe diameter is large and the pressure is small. If the caliber is small and the pressure is high, the welding gate valve is generally selected. However, some customers will consider whether the welding gate valve will be more troublesome than the flange gate valve in maintenance. After all, welding costs are higher. It is also not easy to disassemble like a flange. How to choose it?
Let us analyze it now. Because the flange gate valve can be directly disassembled and replaced, the flange gate valve has better applicability than the welding gate valve. However, for high-pressure conditions, the flange connection is not as stable as welding (combustible and explosive media are considered separately). Moreover, because the welding gate valve has fewer leakage points at the inlet and outlet, the sealing performance is superior to the flange connection. Generally, high temperature and high pressure and important position valves are connected to the pipeline by welding, especially in the position where the temperature difference is alternately changed, such as the main steam pipeline. The temperature difference between the working state and the shutdown of the pipeline is huge. In this alternation of the hot and cold temperatures, the metal generates a large thermal strain, which may cause leakage at the joint. Welding is a complement to this situation. If it is high temperature, high pressure, and high toxicity pipelines, it is still better to use welding instead of flanges. This can really reduce the leakage point, which is more favorable for safety and investment reduction. It is also a misunderstanding that the welding gate valve is difficult to repair. In fact, it is very convenient to repair the cutting tool now, even if it is replaced.
The biggest advantage of the flange gate valve is that it is convenient to install and replace. However, it is generally bulky. The flange connection is easy to leak. However, from an economic point of view, when the valve is the same working temperature, working pressure and nominal diameter, the welding gate valve is much more expensive than the flange gate valve. It also has high quality requirements for products. Naturally, the product materials will be screened strictly. Therefore, if the pipe pressure is not very large or it needs to be cleaned frequently, the flange gate valve will be fine. It is convenient to replace, clean and repair. In the specific working conditions, most valves can be repaired without being removed from the pipeline. The effect is also very good.
In summary, the choice of flange gate valve or welding gate valve is actually not related to maintenance, because this is not a difficult problem to deal with. When we choose the valve of what connection method, what kind of media and operating environment should be referred to, which is mainly depends on the needs of the site. Routine working conditions are recommended to use a flanged gate valve, which is convenient for maintenance. When the medium is high pressure, highly toxic, expensive fluid, it is recommended to use a welded gate valve, which can reduce the leakage point. It should be emphasized here that when purchasing a gate valve, the user should select a manufacturer with reliable quality, qualification and service, so as to reduce the valve maintenance rate, or only need to deal with the sealing surface during maintenance. For more information on flange valve, please pay attention to the Bundor Valve!