How Do Pump Seals Work?

Pumps are devices that move fluid volume by mechanical or physical action. Pumps use a particular kind of seal in order to prevent leakage.

Mechanical Seals

Pump seals contain flexible components that keep rotating pumps from leaking.

Pump devices contain a rotating shaft, generating constant movement that can cause a standard seal to leak fluid. Pumps use mechanical seals, a type of seal with rigid and flexible elements that compensate for the rotation of the pump.

Sealing Surfaces

Pump seals contain primary and secondary sealing surfaces. The primary surface is made up of a hard material such as tungsten carbide, and a softer material often made of carbon. This material attaches to the pump casing. The softer material is embedded in the rotating assembly of the pump seal. The sealing surfaces take the form of rings that physically contact each other. One seal ring remains stationary, while one rotates in sync with the pump.


A method of actuation is necessary to maintain contact between the seal’s sealing surfaces. This contact is provided by an actuator, a mechanical device designed to control or move a mechanism. In typical pump seals, the actuator takes the form of a spring, which is operated via pressure generated by the sealed fluid.