HLPS SEAL 10-27-8.5, 03931063-315 CATERPILLAR FUEL PUMP
The High/Low Pressure Seal (HLPS) from Freudenberg Sealing
Technologies is a field-proven, specialty-designed, high-pressure
Simmerring® shaft seal. The HLPS is a severe duty pressure seal
and has a unique design with several features that greatly improve
its overall performance.

This seal is ideal for hydrostatic drives subject to very high stress.
Unlike most high pressure seals, the HLPS uses a proprietary
spring-less lip to perform the sealing function, which allows it to
withstand pressure up to 200 bar. The PTFE insert makes the seal very
resistant to frictional wear. The inner metal case molded into the
seal supports the main LIP while the heavy duty outer case maintains
the overall correct geometry even under high pressure spikes.
General Features of the HLPS
Typical compounds are HNBR with PTFE back-up ring
Temperature range is –40°C to +120°C
Pressure range—maximum 200 bar
Surface speed—1.5m/s