The TST254SO is an AS568-254 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 5.484 in (139.29 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.762 in (146.35 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
This material stands up to oxidizing media, strong acids and bases, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) is valued for excellent dielectric properties and a very wide continuous service temperature range. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service.
You will find this material specified across food and beverage, semiconductor fabrication, and pharmaceutical and biotech.
Order part number TST254SO, sold individually. Nominal inside diameter is listed as 5 1/2 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Description 254 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 5.484 inch (139.29 mm)
Actual Outside Diameter 5.762 inch (146.35 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings