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ST-P4-BU Metric Teflon Back-Up Ring


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  • Model: ST-P4-BU
  • 159 in Stock

1.5mm CS X 4mm ID X 7mm OD - “P” Series Metric Back-up Ring Sizes

Ring dimensions conform to Japanese Industrial Standard, JIS B 2407

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.