A brief discussion on the causes and hazards of valve leaks in oil depots – Gate valves

Thread Content

With the continuous development of modern industry, the demand for valves is on the rise. The number of valves needed for an ordinary oil depot can range from a few hundred to several thousand. In oil depots, valves are the most widely used and frequently operated mechanical components; however, due to improper use and maintenance, leaks often occur. This can lead to unnecessary accidents and energy waste, among other things. The accident taught people that to obtain high-quality valves, new and stricter requirements must be imposed on them. Minimize the occurrence of leaks from the valve. Based on my previous brief work experience at oil depots and my current maintenance experience, I will briefly explain the causes and hazards of valve leakage. Reasons for leakage: Leakage can be categorized as external leakage and internal leakage. For gate valves, external leaks generally occur in the valve body, valve cover, and valve stem. Internal leakage is friction at the sealing surface. External leakage: Leakage from the valve body and valve cover may be due to poor manufacturing quality, with defects such as sand holes and inclusions ； Another issue is the poor quality of the materials, which can lead to cracking due to freezing or leakage as a result of being struck by heavy objects. The valve stem leaks, as the gate valve is of the lift-type design; just as we say, when pulling out a radish, mud comes along with it. The direction in which the medium escapes is the same as the direction in which the valve stem moves upward, so the liquid can easily be carried out along with it. To prevent the liquid from escaping, we add a seal at the lift rod, which is what we call a packing. The choice of filler is subject to certain requirements; it must be selected based on factors such as the presence of corrosion, as well as high or low temperatures. If the wrong filler is chosen, sealing will not be achieved. At the same time, fillers also have a limited service life; once that period is exceeded, they age and lose their elasticity, resulting in failed sealing. Furthermore, as the number of operations increases, the sealing compression effect of the filler gradually diminishes. Internal leakage: Due to price considerations, wedge gate valves are commonly used. They achieve sealing by rotating the gate plates on either side to press against the valve seat; friction occurs during this rotation, and frequent opening and closing leads to leakage at the sealing surfaces. Harm of leaks: The dangers of external leaks are obvious; they can cause fires, explosions, poisoning incidents, and environmental pollution. Internal leakage is undoubtedly a waste of energy in both single-pipe and separate-pipe systems; in dual-pipe systems, it also leads to oil mixing. My experience is limited; feel free to add more!