Mechanical seal selection and installation

Mechanical seal selection
The proper selection of a mechanical seal can be made only if the full operating conditions are known:

1. Liquid

2. Pressure

3. Temperature

4. Characteristics of Liquid

5. Reliability and Emission Concerns

1. Liquid: Identification of the exact liquid to be handled is the first step in seal selection. The metal parts must be corrosion resistant, usually steel, bronze, stainless steel, or Hastelloy. The mating faces must also resist corrosion and wear. Carbon, ceramic, silicon carbide or tungsten carbide may be considered. Stationary sealing members of Buna, EPR, Viton and Teflon are common.

2. Pressure: The proper type of seal, balanced or unbalanced, is based on the pressure on the seal and on the seal size.

3. Temperature: In part, determines the use of the sealing members. Materials must be selected to handle liquid temperature.

4. Characteristics of Liquid: Abrasive liquids create excessive wear and short seal life. Double seals or clear liquid flushing from an external source allow the use of mechanical seals on these difficult liquids. On light hydrocarbons balanced seals are often used for longer seal life even though pressures are low.

5. Reliability and Emission Concerns: The seal type and arrangement selected must meet the desired reliability and emission standards for.

Mechanical seal installation
Type with mechanical seal installation method, the different types of machines vary, but almost all essentials the same installation, installation procedures and precautions are as follows:

(1) to determine the size of installation

Installation, shall be the product manual or sample size to ensure the installation of spring saddle.

(2) Before loading the shaft (sleeve), gland should be no burr, bearing in good condition; seals, shaft seal chamber, gland should be clean. To reduce friction, mechanical shaft seal parts to be installed coated with a thin layer of oil for lubrication, taking into account the rubber O-ring compatibility, if not oil, can be coated with soapy water. Floating-mounted anti-static ring resale without the structure, not oiled, into the gland should be dry.

(3) First stationary ring mounted on the shaft together with the gland, careful not to collide with the axis, and then into the ring component. Or the driving seat spring seat set screw should be tightened evenly several times.

Gland without fixed before hand to push the compensation ring for axial compression, automatic release after the compensation loop can bounce no wiring, and then tighten the gland bolts evenly.