Fluid in mechanical seal may leak through 4, respectively the stationary ring and capping, capping of the seal between the casing, both seals are static seals. Channel b is rotating seal between the ring and the shaft. But when the surface wear, it can only be with the compensation ring along the axis trace moving, but he still is a relatively static sealing. Therefore, these leak path is relatively easy to block. Most commonly used static sealing elements rubber o-rings or PTFE v-ring, but as compensation or stationary ring auxiliary seal ring turn the ring, sometimes use both Springs functional rubber, Teflon and metal bellows structure. Rotating ring section of each other with the stationary ring for sliding seals. Therefore, the processing requirements for seal face is very high (flatness 0.0009mm, surface roughness: Ra ≤ 0.1 μ m hard ring, soft ring Ra ≤ 0.2 μ m). In order to maintain the necessary lubrication film between the seal faces must strictly control end surface pressing force per unit area. Units on the face too much pressure, difficult to form a stable lubricating film will accelerate the wear of sections. Section units pressure is too small, leakage increased. So, to get a good seal has a longer life expectancy, when installing the mechanical seal, always keep the end pressure value in the appropriate range.