Mechanical seal

What is a mechanical seal?

A mechanical seal is a device designed to seal a rotating shaft against a stationary housing, e.g. a pump shaft against a pump casing. The stationary components will consists of a seal ring and (depending on the design) a spring-loaded element. The spring-loaded element can be a spring or a bellows. The seal ring is sealed against housing with secondary gasket, e.g. an O-ring. The rotating components will consist of a seal ring and (depending on the design) a spring-loaded element.

The spring-loaded element can be a spring or a bellows. The seal ring is sealed against the shaft with secondary gasket, e.g. an O-ring.

A mechanical seal can be supplied as a pre-assembled cartridge or in separate components.

Assembly is done in accordance with the assembly drawing.

A mechanical seal will run in the pumped product or external source fluid. To provide lubrication, a film of liquid must always be present between the seal faces. The sealing surfaces are separate from each other by the seal liquid film during shaft rotation and in principle operate without contact and thus minimal wear under these conditions.

The proper functioning of a mechanical seal is only achieved once the following have been met:

§ The sealing surfaces are lapped within specification.

§ Perpendicularity and concentricity between the shaft and the seal chamber face and bore respectively.

§ Freedom of movement of the spring-loaded components in axial direction.

§ Axial and radial shaft movements within prescripted tolerances field.

§ The seal is operated under the conditions for which it was selected.

§ The equipment in which the seal(s) is (are) installed is operated within normal parameters (no cavitation, excess vibration, etc.).

§ Prevention of sedimentation on shaft or sleeve surfaces, caused by for instance crystallisation or polymerisation.

§ Permanent seal liquid film between the sealing surfaces.

Failure to meet these requirements will result in excessive leakage and/or shortened seal live.

In addition with last post the mechanical seal manufacturer will provide for your service the optim solution. Also each manufacturer has a mecahnical seal catalog to guide the client in his decision .

your data lack so much information. . . for example: what is th application, is it located in a hasardous area?, what kind of centrifugal pump do you want to put the mech'l seal, does the medium has particles with it or does it has an activated carbon with it . . .

there are so many mechanical seal design available, from a single spring to multiple spring, from a single cartridge to a double cartridge design. . . .even the material available should be picked right for your medium. . . .

first gather some data about the medium, example: temperature, viscosity, is it flammable or volatile, etc, and the kind of centrifugal pump you are using. By then we can come up with the right mechanical seal

Due to its softness, indium is considered an ideal material to create a compression seal in cryogenic applications, vacuum pumps, and in heat-sensitive areas.
Han Billion Metals and Chemicals Co., Ltd (http://www.hanbillion.com) supplies indium preforms in various shapes including flat washers, "O" rings, discs and rectangles. Foil and wire are available for custom seal fabrications.
Please feel free to contact us for more details and pricing.