As we all know, the raw material tape is used to seal the joints of the pipes to make the pipes more tightly sealed. If the seal is not good, leakage will occur. As it stands, leakage is a common phenomenon in nature. Leaks of tap water and gas in daily life often bring inconvenience and even harm to people; in industries such as pressure vessels, pipelines, reactors, valves, hydraulic equipment, and transportation tools, once leakage occurs, it will cause a large amount of energy and raw materials. Waste, equipment can not work normally, and it will lead to scrapped equipment, paralysis of the entire factory or system, casualties and serious environmental pollution. Therefore, people do everything possible to prevent and eliminate leakage in production practice. Sealing refers to the phenomenon that there is no leakage at the joints of machines and equipment. Parts that can play a sealing role are called seals. More complex sealing connections are called sealing systems or sealing devices. Commonly used sealing equipment includes raw material tape, sealant, adhesive, etc. In engineering practice, the concept of tightness or tightness is often used to evaluate the effectiveness of sealed connections. The tightness of the system and equipment can be determined by the size of the leakage rate. In a physical sense, there are no absolute compacts. The so-called tightness should be like other physical quantities. can be measured quantitatively. The literature defines the tightness of the connection as: "Under certain operating conditions, the leakage rate of the connection is lower than a specified index leakage rate; or under the specified leakage rate index, the connection can withstand specific operating conditions. Meet the above The connection of the condition is close, otherwise it is not close". In fact, the leakage rate of the connection is closely related to the leak detection conditions, leak detection methods, and leak detection personnel. The test results obtained by different testers or using different leak detection methods and different simple leak equipment are often inconsistent. Therefore, the literature has made a stricter definition of the close relationship between the system and equipment: "Under a certain operating condition, the leak rate measured by a specified leak detection method with a corresponding test resolution is lower than a certain A specified index leakage rate. Systems and equipment that meet the above conditions are tight, otherwise they are not tight."