Ordered as TST153SO, this is an AS568-153 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 3.487 in (88.57 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 3.693 in (93.8 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 one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. This material stands up to steam, strong acids and bases, and solvents. Published continuous service range is -65°F (-53.9°C) to 500°F (260°C). Applications involving elemental fluorine at temperature or service requiring elastic recovery call for a different compound.
It sees regular use in pharmaceutical and biotech, semiconductor fabrication, and chemical processing.
Order part number TST153SO, sold individually. Nominal inside diameter is listed as 3 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Description 153 PTFE SOLID BACKUP RING FDA
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 3.487 inch (88.57 mm)
Actual Outside Diameter 3.693 inch (93.8 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings