New hydraulic fluids and changing operating parameters such as pressure and temperature, are being introduced into the
industry at a rapid rate. In order to keep up with the new demands, new seal materials are being developed to extend
service life.
The following factors must be considered when choosing seal material:
TEMPERATURE COMPATIBILITY
Temperature Compatibility is one of the prime considerations involved in seal material selection. In selecting a seal
material, the user must determine the upper and lower extremes at which the seal will be expected to function and also
take into account the time (duration) to which these extremes of temperature excursion will be experienced, bearing in
mind that compression set (and therefore seal-ability) is a function of the time/temperature relationship.
PRESSURE COMPATIBILITY
Pressure Compatibility is another consideration when selecting a seal material. This characteristic is determined by
the durometer (hardness) of the material and by its internal chemistry.
FLUID COMPATIBILITY
Fluid Compatibility is the final requirement for material selection. As all elastomers are affected to some degree by
their fluid environment, it is vital that a material be selected that will be affected the least by the fluid and
again, there is the factor of time to be considered. A material which may be fine for 100 hours @ 200°F in the
specified fluid may soften just enough @ 400 hours to extrude during a high pressure excursion.
For more sealing information, please contact a RAM engineer.
