*2107-251 PTFE SPIRAL B/U FDA

Ordered as TSP251, this is an AS568-251 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 5.109 in (129.77 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.387 in (136.83 mm). The back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, PTFE (Teflon) is known for non-stick, non-contaminating surface characteristics and a very wide continuous service temperature range. The compound resists solvents, oxidizing media, and steam. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). It should not be specified for service in service requiring elastic recovery or elemental fluorine at temperature.

You will find this material specified across food and beverage, aggressive-media pipelines, and semiconductor fabrication.

Reference part number TSP251 when ordering; the item is sold individually. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.