Quick Couplings Seals & Gaskets
What Seal Do I Need For My Quick Coupling System?
There are a number of considerations when choosing the correct seal for your quick coupling (also called a quick disconnect). Quick couplings are often used in fluid lines and choosing the right seal is important to the operational performance alongside, specifications such as pressure and flow requirements.
Choosing the right seal is vital and can be the difference between a fully working system or a quick coupling system that is likely to fail. There are two main factors to take into account; the chemical compatibility between the seal material and the medium being transferred and the heat tolerance or the operational temperature.
Here we have compiled a quick reference guide of the most commonly used quick disconnect seals and the applications they are recommended for.
FPM, FKM & Viton Seals
Fluoro-Rubber Seals for Quick Couplings
As can be seen, there are a few variations of the abbreviations for this staple material. This can cause confusion, but essentially FPM, FKM and Viton are all one and the same base material, Fluoro-Rubber.
Fluorocarbon Rubber Seals are the most frequently used seals in most quick coupling systems.
- FPM - is an international abbreviation and is in accordance with both the ISO and DIN standards
- FKM - is used to stand for Fluoroelastomer and this is used in accordance with the American Standard
- VITON – this is, in fact, a brand name and is the registered trademark of DuPont Performance Elastomers
Operational Temperature: -20 to +400 deg.F (-28deg.C to 204deg.C)
FPM Seals are recommended for:
- Petroleum Oils
- Di-ester Base Lubricants
- Silicate Ester Base Lubricants
FFKM – Perfluoroelastomer Seals for Quick Fittings
This material is also commonly known as Kalrez, Chemrez & Perlast, which are all registered trade, marks.
This is also a very popular choice. This material is super tough. It is an elastomeric version of Teflon and so this means that the chemical resistance is superior. They are less likely to cold-flow than Teflon seals, but at the same time, they resist chemical attack by nearly all chemicals where other elastomers can degrade and become swollen.
Operational Temperature: Please be advised that this material’s temperature rating varies depending on the grade. It is advised to check on a case by case basis depending on your application.
FFMK Seals can be used in many varied applications due to their superb resistance qualities and subsequent durability against real aggressive chemicals.
Nitrile or Buna Nitrile (NBR) Seals for Quick Disconnect Fittings
Another commonly used seal type for quick couplings, the Buna Nitrile seal is usually fitted as standard in most Parker quick release fittings as well as the ASL QuickBreak range of quick disconnect fittings.
Operational Temperature: -65 to +250 deg.F (-53deg.C to 121deg.C)
NBR Seals are recommended for:
- General Purpose Sealing
- Petroleum Oils & Fluids
- Silicone Greases & Oils
- Di-Ester Base Lubricants
- Ethylene Glycol Base Fluids
Ethylene Propylene Rubber (EPM) Seals for Quick Couplings
Probably the most versatile of all the seal materials, these seals feature a wide temperature range and are compatible across of a number of mediums.
Working Temperature Range -65 to +300 deg.F (-53deg.C to 141deg.C)
EPM is recommended for:
- Phasphate Ester Base Hydraulic Fluids (Skydrol, Cellulube, Pydraul)
- Steam (to 400 deg F)
- Silicone Oils & Greases
- Diluted Acids
- Diluted Alkalies
- Automotive Brake Fluids
Chloroprene Rubber (CR) or Neoprene Seals for Quick Disconnect Couplings
A slightly more exotic seal - available on request
Neoprene (Polychloroprene or PC-Rubber) is a synthetic rubber and provides excellent chemical stability whilst maintaining flexibility. A wide temperature range is also possible with Neoprene seals.
Working Temperature Range -65 to +300 deg.F (-53deg.C to 148deg.C)
CR Seals are recommended for:
- Refrigerants (Freon, NH3)
- High Aniline Point Petroleum Oils
- Mild Acid Resistance
- Silicate Ester Lubricants
We hope this guide is helpful in outlining some of the most common types of seal used with quick disconnects, but you may want to also check out some further resources. We have a Chemical Compatibility Chart for a more detailed overview of over 300 different chemicals. You can also check the Information Centre for the relevant product data sheets or check the Quick Couplings product section. Or of course, you can simply ask your friendly supplier who should be able to guide you.
NOTE: This Post should serve as a guide only. All seals must be specified individually for each application.
If you require any further information, please call the Sales Team on 01235 512500 or get in touch via email firstname.lastname@example.org