2103-177 PTFE S/T BUP FDA

TST177 is an AS568-177 white PTFE (Teflon) 55 Shore D Back-Up Ring built to an inside diameter of 9.487 in (240.97 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 9.693 in (246.2 mm). In service, this back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Expect good resistance to solvents, steam, and strong acids and bases. That behavior comes from the compound itself: PTFE (Teflon) is valued for non-stick, non-contaminating surface characteristics and one of the lowest coefficients of friction of any solid. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It is not the right choice where service requiring elastic recovery or elemental fluorine at temperature are present.

Maintenance and OEM teams specify it across chemical processing, semiconductor fabrication, and pharmaceutical and biotech.

Stocked as TST177 and sold individually. Nominal inside diameter is listed as 9 1/2 inch. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.