FKM and EPDM are common &#;O&#; ring materials that offer excellent thermal and oxidation resistance. However, there are some significant differences between these two polymer materials, which, depending on your application, can make or break your choice of &#;O&#; ring material. Here, TRP Polymer Solutions talks us through the various advantages and disadvantages of FKM and EPDM.
Goto Sanshi to know more.
FKM: Fluoroelastomers (FKM) are characterised by their strong carbon-fluorine bonds, which give them the advantage of exceptional chemical, thermal and oxidation resistant properties. FKM also offers a wide operational temperature range of -45 °C to +204 °C, has good mechanical properties, and its density gives a high-quality feel.
EPDM: EPDM offers excellent resistance to ozone, sunlight and weathering. Few rubbers can withstand extremely cold temperatures like EPDM. With an operating temperature as low as -50 °C (with highs of +150 °C), EPDM is a solid choice in sub-zero temperatures. EPDM compresses well and is highly resistant to tears, abrasion and steam.
FKM: FKM is known to swell in fluorinated solvents and cannot be used with molten or gaseous alkali metals. FKM is a premium product, due to its chemical makeup. So it does come with a higher price tag than other non-fluorinated hydrocarbons and low temperature grades can be especially costly.
EPDM: Although EPDM offers good resistance to dilute acids, ketones and alkalis, it does not fare so well fuels, oils and non-polar solvents. It certainly wouldn&#;t be a suitable choice for petro-chemical applications.
FKM: FKM is suitable for explosive decompression, CIP, SIP and FDA applications. It is ideal for the handling and transportation of chemicals and fuels, as well as high temperature and explosive environments, such as in the oil and gas, automotive and aerospace industries.
EPDM: EPDM&#;s all-round durability has seen it employed across a wide range of applications, including &#;O&#; rings, automotive cooling systems, and as insulation in freezer room seals.
Contact us to discuss your requirements of FKM Oil Seal. Our experienced sales team can help you identify the options that best suit your needs.
FKM: If your application demands the highest standards of chemical, thermal and oxidation resistance &#; and budget is not your primary concern &#; FKM is a premium product that will more than repay your investment.
EPDM: For a low-cost sealing material that performs well in outdoor applications, EPDM is a good choice. This durable synthetic rubber won&#;t degrade under UV conditions and will tolerate prolonged contact with steam and some acids.
Choosing the wrong &#;O&#; ring material can lead to rapid failure, which is why you should always seek expert advice. TRP Polymer&#;s technical experts have many years of experience developing high-performance sealing materials and can help you to source the right &#;O&#; ring material for your application.
For more information, please visit TRP Polymer Solutions.
POLYACRYLATE (ACM) Rubber
FLUOROCARBON (FKM) Viton
I've been thinking about replacing my harmonic balancer and the crank seal. I've seen several posts in forums recommending that you NEVER use a Viton seal on an object in motion, with several people saying their new Viton seals leaked almost immediately.
Clark's used to sell both rubber and Viton seals, but now only offer the Viton seals in their catalog.
In reading the more objective scientific articles online comparing seal materials, one specifically stated that Vito was especially well suited to sealing high speed rotating parts. That contradicts some of the very strongly stated anecdotal posts I've read.
Both ACM rubber and Viton have a high resistance to gasoline and oil, with Viton said to have a higher resistance to breaking down from contact with petroleum products.
One place where ACM rubber comes out way ahead is in remaining flexible at low temperatures with Viton losing flexibility at 5 degrees F while ACM rubber remained flexible down to -40 degrees F (not that I expect to be operating my car in such cold weather).
I see an SKF seal (what I call a quality brand) still being sold using ACM rubber for the seal material. My guess is that this part would perform very well. On the other hand, Clark's only sells Viton seals, and I can't imagine that they would only sell Viton if there was a high failure rate. I CAN see them no longer stocking rubber seals if everyone is demanding Viton and not buying rubber.
So, here we are again where respected people at the forums seem to be making strong recommendations based upon actual experiences they have had that seem to contradict the scientific evidence.
How do you decide between rubber and Viton under those circumstances?
(I've made a point use Viton seals in non-rotating applications so far, such as the oil cooler seals.)
Glen in Ohio
Monza Sedan Powerglide 110 hp
Low mileage survivor, stock as delivered
Records back to in Pequot Lakes, Minnesota
Original dealer Mike Turk's in East Liverpool, Ohio
Located in Cleveland, Ohio area
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