AS568-438 FFKM O-Ring — 158.12 × 6.99 mm
A very thick section for the largest diameters and most severe static sealing duties. With an inside diameter of 158.12 mm and a 6.99 mm cross section, this is a large-bore seal for large-bore machinery and process 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 | AS568-438 |
|---|---|
| Inside diameter (ID) | 158.12 mm (6.225 in) |
| Cross section (CS) | 6.99 mm (0.275 in) |
| Outside diameter (OD) | 172.1 mm (6.776 in) |
| Material | Aperflu 2275 perfluoroelastomer (FFKM) |
| Service temperature | up to 200 °C continuous |
Pharmaceutical and food processing
Steam-in-place and clean-in-place cycles, aggressive cleaning agents and potent active pharmaceutical ingredients (APIs) demand a seal that stays inert and dimensionally stable. Aperflu 2275 is suited to product-contact and CIP/SIP duties where extractables must be kept to a minimum.
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
Large-diameter flanges, autoclave and reactor seals, structural static joints, 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.
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