China's chemical and petroleum enterprises began to use mechanical metal seals
on centrifugal pumps in the early 1960s. It has a history of more than 40 years. By the 1990s, the sealing technology has approached the world advanced level. Some efforts have been made in sealing medium of high temperature, low temperature, high pressure and suspended particle. But the technical level development is not balanced, seal manufacture and the maintenance level vary among regions.
With the emergence of new technology, mechanical metal seal technology level is also improving. At present, mechanical metal seal has been widely used in compressor and centrifugal pump. As far as the universality of mechanical metal seals is concerned, it has largely replaced the old sealing technology such as packing seal and shown great advantages. In general, mechanical metal seal performance is difficult to predict, and its service life is far less than the life of rolling bearings. This means parking the car to replace the rotary joint, wasting a lot of manpower and material resources, and paying a huge amount of maintenance costs. Some mechanical metal seal leakage also caused the whole device to stop production, and explosion, fire, personal injury accidents.
With the progress of science and technology and the development of industry, it is imperative to research and develop new sealing structure, to improve sealing performance, to improve safety and stability reliability, and to extend the service life of mechanical metal seals, for example, rotary joint seal, combination seal, seal ring seal, fluid dynamic seal, multi-pole seal, magnetic seal, and so on. The use of seals is also expanding, and the development of mechanical seals requires attention to the auxiliary system. In order to extend the overhaul cycle of the device, enterprises now require the service life of mechanical metal seals to be trouble-free within 365 days.