Teflon PTFE Back-up Rings are designed to prevent extrusion in rubber O-ring sealing systems. The amount of this extrusion is affected by O-ring hardness, operating temperature, operating pressure and clearance of the mating surface.
Increased Pressure: The use of Back-up Rings should be considered for systems with operating pressure above 2000 PSI. At these pressures the mechanical forces applied to the O-Ring may cause extrusion of the O-ring into the clearance gap.
Operating temperature: The use of Back-up Rings should be considered for elevated temperatures greater than 160°F (71C). The physical and mechanical properties of O-rings may be affected at these temperatures, this increasing the risk of extrusion into the clearance gap.
Industrial Trends: Today's fluid power systems continue to move towards higher pressures and temperatures. Teflon PTFE Back-up Rings should be considered as a reliable component to achieve satisfactory system performance