Ordered as TST044, this is an AS568-044 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 3.739 in (94.97 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 3.879 in (98.53 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
PTFE (Teflon) is specified here for excellent dielectric properties and very wide continuous service temperature range. It resists oxidizing media, steam, and strong acids and bases. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C).
Common environments for this compound include food and beverage, aggressive-media pipelines, and chemical processing.
Stocked as TST044 and sold individually. Nominal inside diameter is listed as 3 3/4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Description 2103-044 PTFE S/T BUP FDA
Actual Cross Section 0.07 inch (1.78 mm)
Actual Inside Diameter 3.739 inch (94.97 mm)
Actual Outside Diameter 3.879 inch (98.53 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings