Part number TST250 is an AS568-250 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 4.984 in (126.59 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.262 in (133.65 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
The compound resists strong acids and bases, oxidizing media, and solvents. PTFE (Teflon) is widely chosen for excellent dielectric properties and non-stick, non-contaminating surface characteristics. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Verify compatibility before use with elemental fluorine at temperature or service requiring elastic recovery.
Common environments for this compound include food and beverage, laboratory equipment, and pharmaceutical and biotech.
Stocked as TST250 and sold individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Description 2103-250 PTFE S/T BUP FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 4.984 inch (126.59 mm)
Actual Outside Diameter 5.262 inch (133.65 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings