253 PTFE SOLID BACKUP RING FDA

Ordered as TST253SO, this is an AS568-253 white PTFE (Teflon) 55 Shore D Back-Up Ring supplied with an inside diameter of 5.359 in (136.12 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.637 in (143.18 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

The material holds up against strong acids and bases, oxidizing media, and nearly all industrial chemicals. PTFE (Teflon) is specified for a very wide continuous service temperature range and near-universal chemical inertness. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). Applications involving molten alkali metals or service requiring elastic recovery call for a different compound.

Typical settings include laboratory equipment, chemical processing, and aggressive-media pipelines.

Reference part number TST253SO when ordering; the item is sold individually. Nominal inside diameter is listed as 5 3/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.