By a pair of mechanical seals is perpendicular to the axis or the number on the relative sliding of the end for the fluid pressure and the compensation mechanism in the elastic (or magnetic) to keep under seal affixed to merge to achieve together with auxiliary shaft seal leakage resistance device.

 Common mechanical seal shown in Figure 1. From the stationary ring (stationary ring) 1, rotating ring (ring) 2, elastic element 3, spring seat 4, 5, set screws, rotating auxiliary ring ring ring supporting ring 6 and 8 and other stationary components, anti resellers 7 fixed to the gland to prevent the stationary ring 9 on the turn. Rotating ring and stationary ring often can be compensated according to whether they have the ability to axial or non-compensation is also known as the compensation ring.

 Mechanical seal leakage of fluid channels may have in Figure 1 A, B, C, D four channels.

 C, D leak paths are stationary ring and the gland, the seal between the shell gland, the two are static seal. B-channel is the axis of rotation between the ring and the seal, when the face friction and wear, it can follow only compensate for the small amount of ring movement along the axis, in fact, still a relatively static seal. Therefore, these leaks are relatively easy to block channels. The most commonly used static sealing rubber O-ring or PTFE V-ring, and as compensation for the rotation of ring secondary seal rings or still rings, and sometimes both elastic element functions using rubber, PTFE or metal bellows Structure.

 A channel is a rotating ring and stationary ring affixed to end cooperation with each other relative sliding seals, mechanical seal device which is the main seal, also decided to mechanical seal performance and longevity of the key. Therefore, the processing requirements of seal face very high, between the seal faces in order to maintain the necessary lubrication film, the system must be strictly cavity-side surface of the unit area pressure, the pressure is too large and difficult to form a stable lubricating film, will accelerate the end Wear; pressure is too small, increase of leakage. Therefore, to obtain good sealing performance and a sufficient life, in the design and installation of mechanical seals, we must ensure that the pressure per unit area of ​​face value in the most appropriate range.