Kalrez 4079 FFKM O-Ring: Compound, Equivalents, UK Suppliers
Verified by Rachel Mayfield, Supply Chain Analyst - April 2026
Kalrez 4079 is a 75 Shore A perfluoroelastomer (FFKM) manufactured by DuPont (Chemours). It seals continuously to 316°C and is specified for steam and similar service. Broad-spectrum FFKM with perfluorinated ether backbone.
Specifications
| Property | Value |
|---|---|
| Compound | 4079 |
| Manufacturer | DuPont (Chemours) |
| Maximum continuous temperature | 316°C |
| Minimum temperature | 0°C |
| Hardness | 75 Shore A |
| Colour | Black |
| Material family | Broad-spectrum FFKM with perfluorinated ether backbone |
Where Kalrez 4079 is used
Kalrez 4079 is specified for: Steam, hot amines, ethylene oxide, sour gas, refinery valves, pulp and paper digesters.
Limitations: Not recommended for fully fluorinated solvents; cost.
Kalrez 4079 equivalents from other FFKM manufacturers
If Kalrez 4079 isn't available, these compounds from competing manufacturers have similar chemistry and operating windows. Always verify against your actual fluid and temperature before substitution.
| Equivalent compound | Manufacturer | Max temp | Hardness | Direct match |
|---|---|---|---|---|
| Chemraz 615 | Greene Tweed | 324°C | 75 Shore A | ✓ |
| Simriz SZ487 | Freudenberg-NOK | 300°C | 75 Shore A | ✓ |
| Perlast G75B | Precision Polymer Engineering | 327°C | 75 Shore A | ✓ |
| Markez Z40 | Marco Rubber | 316°C | 75 Shore A | ✓ |
| Isolast J9504 | Trelleborg Sealing Solutions | 270°C | 75 Shore A | approx |
Available O-ring sizes
Kalrez 4079 is supplied in:
- BS 1806 sizes: BS001 to BS932 (UK / EU standard, imperial-origin metric)
- AS568 sizes: -001 to -932 (US standard, dimensionally identical to BS 1806)
- ISO 3601 sizes: metric IDs from 2 mm to 670 mm with cross-sections 1.0 mm to 7.0 mm
- JIS B 2401: P, G, S series (Japanese OEM equipment)
- Custom / non-standard: built-to-print for OEM applications
For a list of sizes commonly stocked in the UK, see the BS 1806 size chart, ISO 3601 metric chart, or contact a UK seal specialist below.
UK availability
Kalrez 4079 is supplied in the UK by FFKM specialists carrying multiple manufacturer lines. Lead time is typically 2-5 working days for stock sizes, 4-8 weeks for custom-moulded sizes. Use the form below to get a quote from a UK FFKM specialist.
Manufacturer datasheet
Official DuPont (Chemours) datasheet: Kalrez 4079 TDS (PDF)
Frequently Asked Questions
What is Kalrez 4079 used for?
Kalrez 4079 is a 75 Shore A FFKM (perfluoroelastomer) compound from DuPont (Chemours). It is used in Steam, hot amines, ethylene oxide, sour gas, refinery valves, pulp and paper digesters. Continuous service temperature: 0°C to 316°C.
What is the temperature rating of Kalrez 4079?
Kalrez 4079 has a continuous service temperature range of 0°C to 316°C. Short-term excursions above the maximum are possible but degrade service life.
What is the equivalent of Kalrez 4079?
Direct equivalents to Kalrez 4079 include: Chemraz 615, Simriz SZ487, Perlast G75B, Markez Z40, Isolast J9504. Always confirm chemical compatibility against your specific fluid before substitution.
How much does Kalrez 4079 cost?
FFKM O-rings such as Kalrez 4079 are typically £30 to £500 per piece depending on size, with custom or large-bore parts at the upper end. Get a current quote via the form on this page.
Where can I buy Kalrez 4079 in the UK?
Kalrez 4079 is supplied in the UK by independent FFKM seal specialists with multi-brand inventory. Lead time is 2-5 working days for stock BS/AS568 sizes, 4-8 weeks for custom-moulded sizes.