How many design forms are there in general for mechanical seals? Machinery Seal

How many design forms are there in general for mechanical seals?

2021-08-04 11:50

There are generally three design types of double mechanical seals, and each type requires a liquid barrier system to be applied between the double sealing surfaces to prevent liquid or gas from leaking out. The commonly used low-cost double seal is a seal installed back-to-back, with the rotating sealing surfaces arranged in opposite directions. It often requires a barrier liquid, the pressure of which should be higher than the pressure of the stuffing box, about 20psi, so as to ensure that the inner seal can always be lubricated by the barrier liquid, and also ensure that the sealing surface reaches a certain sealing pressure.

In the face-to-face type seal with a relatively complex structure, the torsion sealing surfaces are arranged in a face-to-face manner, and they often move in the opposite direction of the same static sealing surface. These seals are available in both high pressure and low pressure barrier fluid systems.

The seal of the third design type adopts a serial arrangement, that is, both torsion sealing surfaces leave the impeller and arrange in the same direction. The barrier liquid pressure of this mechanical seal is generally lower than the pressure of the liquid pump. In fact, it is equivalent to two sealed, two-stage pressure-reducing joint working devices.