ST021 Single Turn Split PTFE Back-Up Ring

AS568-021 (0.053" W X 0.955"ID X 0.049"HT)

Description Primarily an anti-extrusion device, standard back-up rings are used in both static and dynamic sealing. Made of materials that are resistant to pressure induced flow, back-up rings prevent a seal from extruding into the clearance gap between mating parts. The temperatures ranges are -300F to +500F for PTFE.

• Material: Virgin PTFE
• Color: White
• Cross Section: 0.052 Inches / 1.32 Millimeters
• Height: 0.045 Inches / 1.14 Millimeters
• Inside Diameter: 0.96 Inches / 24.38 Millimeters
• Outside Diameter: 1.064 Inches / 27.03 Millimeters
• ASTM Callout: 55 SHORE D DUROMETER VIRGIN WHITE PTFE
• Specification: MS28774

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. PTFE Back-up Rings should be considered as a reliable component to achieve satisfactory system performance