China Sealcon Company

Difference between Single and Double Mechanical Seal

The basic types of mechanical seals for pumps are classified as single mechanical seals, double mechanical seals and series mechanical seals. The single end face mechanical seal consists of a pair of sealing ends; The double mechanical seal consists of two sealing ends. The mechanical seals made up of two or two sets of mechanical seals with E single direction mechanical seals are series mechanical seals. The following two main types of mechanical seals are mainly described to understand the difference between single and double mechanical seals.


1.Single mechanical seal

The single mechanical seal has the advantages of simple structure, low manufacturing cost, convenient installation and operation, and is generally used for oil, water, organic solvents and corrosive medium. There are vertical single stage pipeline centrifugal pumps and horizontal centrifugal pumps which use single side seal pumps.


2.Double mechanical seal

Double mechanical seals are mostly used in flammable, explosive, toxic, granular and lubricating medium. When it is used, it needs a sealing auxiliary system, that is, the isolation fluid is inserted in the sealing cavity between the two ends, thereby improving the lubrication and cooling conditions of the mechanical seal. The pump products that use double mechanical seal are: fluorine plastic centrifugal pump or IH stainless steel chemical pump, etc.

3.Parts and corresponding terms of mechanical seals with single face and double faces

Gasket ring: In mechanical seals, the two ring parts whose ends are perpendicular to the axis of rotation and are relatively slipping are called seal rings.
seal face: The seal face refers to the end surface of the sealing ring which is attached to the other sealing ring at work. The face is usually ground.
Rotating ring (moving ring) : A seal ring for rotating with the shaft.
Stationary ring (static ring) : A seal ring that does not rotate with the shaft.
Compensation ring: Asealing ring with axial compensation capability.
Non - compensation ring: A sealing ring without axial compensation.
Compensation ring component: A part of an axial connection and positioning of an elastic element.
Retainer: That is used to fasten and directly drive a rotating ring with a shaft or sleeve.
Drive screw: Screw used to transfer torque.
Fastening screw: Screw used to fasten a spring seat, drive seat, or other part to a shaft or sleeve.
Clasp: Parts with axial limiting function on the compensation ring.
Reseller: a pin used to prevent the relative rotation of two adjacent parts.
Seal chamber: The annular space between the rotating shaft of the sealing part and the stationary shell.
Sealed chamber: The static shell of the containment chamber;
Elastic components: elastic parts, such as springs or bellows.
Friction couple: a set of sealing rings used for mating.