AS568-218 FFKM O-Ring — 31.34 × 3.53 mm
A robust, high-squeeze section for demanding static and reciprocating seals in larger equipment. With an inside diameter of 31.34 mm and a 3.53 mm cross section, this is a medium-bore seal for mid-size industrial equipment. Moulded from Aperflu 2275 perfluoroelastomer (FFKM) for continuous service up to 200 °C, this seal resists hot acids, caustics, solvents, fuels and steam.
Dimensions
| Dash number | AS568-218 |
|---|---|
| Inside diameter (ID) | 31.34 mm (1.234 in) |
| Cross section (CS) | 3.53 mm (0.139 in) |
| Outside diameter (OD) | 38.4 mm (1.512 in) |
| Material | Aperflu 2275 perfluoroelastomer (FFKM) |
| Service temperature | up to 200 °C continuous |
Semiconductor wafer processing
For non-etch, non-critical areas of semiconductor tooling — such as utility lines, cooling circuits, gas-supply fittings and general wafer handling equipment — Aperflu 2275 delivers dependable, stable sealing performance at a cost-effective price. It is not intended for plasma etch or other critical chamber duties, where dedicated high-purity grades should be selected.
Why Aperflu 2275 FFKM
The compound is moulded, de-flashed and inspected to a burr-free finish, and every batch ships with its own certificate of analysis for traceability.
Typical applications
Hydraulic cylinders, chemical process valves, wellhead and downhole tooling, where Aperflu 2275 outperforms FKM and EPDM in aggressive media and elevated temperature.
Compound properties
| Property | Typical value | Test method |
|---|---|---|
| Hardness | 70 – 71 Shore A | GB/T 39693.4 |
| Tensile strength | 21.2 – 21.8 MPa | GB/T 528 (dumbbell type 2) |
| Elongation at break | 155 – 170 % | GB/T 528 (dumbbell type 2) |
| Compression set, 200 °C × 70 h (25 %, method B) | 15 – 16 % | GB/T 7759.1 |
All values are typical. Every batch is shipped with an individual certificate of analysis and may differ from the typical values listed here.
Chemical resistance
| Media group | Rating |
|---|---|
| Hot organic & inorganic acids | Excellent |
| Caustics (NaOH up to 50 %) | Excellent |
| Ketones, aldehydes, esters, ethers, alcohols | Excellent |
| Solvents, fuels, hydrocarbons, sour gases | Excellent |
| Steam and hot water | Excellent |
| Amines (high temperature, concentrated) | Good – contact us for grade selection |
| Clean-in-place (CIP) / steam-in-place (SIP) agents | Excellent |
| Active pharmaceutical ingredients (APIs) | Excellent |
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