TIANJIN ROYAL INDUSTRIAL SEALS CO., LTD
 
MECHANICAL SEAL SELECTION

The proper selection of a mechanical seal can be made only if the full operating conditions are known. Identification of the exactliquid to be handled is the first step in seal selection.

  • Metal parts must be corrosion resistant, usually plated steel, bronze, stainless steel, or Hastelloy.

  • 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.

Pressure:

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

Temperature:

Can determine the use of the sealing members as materials must be selected to handle liquid temperature.

Characteristics of the Liquid:

Abrasive liquids create excessive wear and shorten seal life.

  • Double seals, or clear liquid flushing from an external source, allow the use of mechanical seals on these difficult liquids.

  • For best results with double (or tandem) seals handling abrasive, the inboard seal faces should be a hard material, such as silicon carbide vs. silicon carbide, while the outboard seal faces should have maximum lubricity, such as silicon carbide vs. carbon graphite.