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2103-388 PTFE S/T BUP FDA

PTFE Back-Up Ring, 18.953 in ID x 0.21 CS, 55D, White, -65 to 500°F

Status
Out of Stock
Est. Ship Date
20 Oct 2026
Material
PTFE (Polytetrafluoroethylene)
Dash Size
388
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
3/16 inch
Nominal Inside Diameter
19 inch
Nominal Outside Diameter
19 3/8 inch
Unit of Measure
EA
SKU:
TST388

Product Specification

-
The TST388 is an AS568-388 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 18.953 in (481.41 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 19.373 in (492.07 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

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

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

Reference part number TST388 when ordering; the item is sold individually. Nominal inside diameter is listed as 19 inch. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Item
TST388
Description
2103-388 PTFE S/T BUP FDA
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
18.953 inch (481.41 mm)
Actual Outside Diameter
19.373 inch (492.07 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings