AS568-021 FFKM O-Ring — 23.52 × 1.78 mm
A compact, low-squeeze section for light-duty static and slow dynamic seals in smaller bore assemblies. With an inside diameter of 23.52 mm and a 1.78 mm cross section, this is a small-bore seal for compact assemblies and small-bore 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 | AS568-021 |
|---|---|
| Inside diameter (ID) | 23.52 mm (0.926 in) |
| Cross section (CS) | 1.78 mm (0.07 in) |
| Outside diameter (OD) | 27.08 mm (1.066 in) |
| Material | Aperflu 2275 perfluoroelastomer (FFKM) |
| Service temperature | up to 200 °C continuous |
Oil refining
Distillation units, catalytic crackers and hydrotreaters expose seals to hot hydrocarbons, sour streams and steam. Aperflu 2275 maintains a stable seal through thermal cycling and aggressive process media.
Why Aperflu 2275 FFKM
Perfluoroelastomer (FFKM) is the most chemically and thermally resistant elastomer class available — rated for continuous use beyond 200 °C and stable against well over 1,600 chemicals, which is why it is specified where FKM, silicone and EPDM fail.
Typical applications
Pneumatic fittings, low-pressure hydraulic circuits, valve stems and quick-connect couplings, 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
The fully fluorinated backbone of Aperflu 2275 resists the aggressive media that attack FKM, EPDM and silicone — including concentrated hydrochloric, nitric, sulfuric and glacial acetic acids, strong caustics, and a broad range of solvents and fuels. Refer to the rating table below for guidance, and confirm your exact media with our engineers.
| Media group | Rating |
|---|---|
| Hydrochloric acid | Excellent |
| Nitric acid | Excellent |
| Sulfuric acid | Excellent |
| Acetic acid (glacial) | Excellent |
| Other hot organic & inorganic acids | Excellent |
| Caustics (ammonia, NaOH up to 50 %) | Excellent |
| Ketones, aldehydes, esters, ethers, alcohols | Excellent |
| Solvents, fuels, hydrocarbons, sour gases | Excellent |
| Steam and hot water | Excellent |
| Ethylene diamine & high-temp amines | Good – contact us for grade selection |
| Clean-in-place (CIP) / steam-in-place (SIP) agents | Excellent |
| Active pharmaceutical ingredients (APIs) | Excellent |
Ratings are typical for peroxide-cured FFKM compounds at room and elevated temperature. Final suitability depends on concentration, temperature and pressure — contact us for a compound recommendation against your specific media.
More AS568 1.78 mm cross-section sizes
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