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2103-238 PTFE S/T BUP FDA

PTFE Back-Up Ring, 3.484 in ID x 0.139 CS, 55D, White, -65 to 500°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
PTFE (Polytetrafluoroethylene)
Dash Size
238
Durometer
55 Shore D
Cross Section Type
Round
Color
White
Minimum Temperature
-65°F (-53.9°C)
Maximum Temperature
500°F (260°C)
Nominal Cross Section
1/8 inch
Nominal Inside Diameter
3 1/2 inch
Nominal Outside Diameter
3 3/4 inch
Unit of Measure
EA
SKU:
TST238

Product Specification

-
Ordered as TST238, this is an AS568-238 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 3.484 in (88.49 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.762 in (95.55 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

PTFE (Teflon) is widely chosen for one of the lowest coefficients of friction of any solid and near-universal chemical inertness. The material holds up against nearly all industrial chemicals, strong acids and bases, and oxidizing media. Rated temperature range runs from -65°F (-53.9°C) to 500°F (260°C) in continuous service.

It sees regular use in chemical processing, pharmaceutical and biotech, and laboratory equipment.

TST238 ships individually. Nominal inside diameter is listed as 3 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Item
TST238
Description
2103-238 PTFE S/T BUP FDA
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
3.484 inch (88.49 mm)
Actual Outside Diameter
3.762 inch (95.55 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings