Oil Seals

An extensive range of Metric and Imperial Seals. Nitrile, Viton and Silicone Materials are available . Rubber Clad Seals as well as Heavy Duty Metal case Seals.

A shaft seal is one component of a three-part system consisting of a shaft, housing, and the seal. The way these components work together in a given application determines which seal design should be specified. In an assembly, the shat rotates or oscillates inside the housing. A clearance gap between the shaft and housing is required to accommodate this motion.

The seal’s function is to prevent fluid inside the assembly from leaking through this clearance gap, as well as to contain pressure and/or to prevent outside contaminants from entering the assembly.

In order to accomplish this task, the seal must operate in two ways. It must provide a tight static seal between the outside diameter of the seal and the housing bore while providing an effective dynamic seal between the moving shaft and the seal lip. Selecting the right seal for each unique operating environment is essential to a properly functioning system.

A Shaft seal is composed of a case for rigidity and a lip for sealing. The case is made of either carbon steel or stainless steel, and the sealing element is made from one of a wide variety of elastomer compounds. The following pages provide information about the application of common seal materials in a variety of applications and temperature ranges.

 

GENEREAL ELASTOMER INFORMATION
NITRILE POLTACRYLATE SILICONE FLUOROCARBON
Temperature Range -40°F to 225°F

(-40°F to 107°C)

-20°F to 300°F

(-29°F to 149°C)

-80°F to 350°F

(-62°F to 177°C)

-20°F to 400°F

(-29°F to 204°C)

Oil Resistance Good Good Fair
Acid Resistance Fair Not Recommended Fair Good
Alkali Resistance Fair-to-Good Not Recommended Good Fair
Water Resistance Good Not Recommended Good Fair-to-Good
Heat Resistance Fair-to-Good Good Good Good
Cold Resistance Good Fair Good Fair
Wear Resistance Good Fair-to-Good Fair Fair-to-Good
Ozone Resistance Poor Good Good Good

 

COMPARISON OF VARIOUS ELASTOMERS
ELASTOMERS STRENGTHS WEAKNESSES
Nitrile
  • Economical
  • Good resistance to petroleum oil, water,silicone oil and grease
  • Good abrasion resistance, cold flow and tear resistance
  • Poor resistance to ozone and aging
Polyacrylate
  • Good resistance to transmission oil, mineral oil, hyphoid gear oil, greases, aging and flex cracking
  • High temperature limit
  • Poor cold temperature limit, dry running ability, water resistance
  • Lower mechanical strength
  • More expensive than Nitrile
Silicone
  • Broad temperature range
  • Good ozone resistance
  • Resistant to compression set
  • Low resistance to hydrocarbon fluids, paraffin fluids and steam above 50 psi
  • Relatively high cost
Fluorocarbon
  • High temperature resistance
  • Broad fluid compatibility
  • Good alternative to Nitrile and Polyacrylate in high temperature applications
  • Fair resistance to water
  • Fair low temperature resistance
  • Higher cost