EPDM vs Silicone Gaskets

We’ve previously discussed some of the differences between different types of gaskets and today we’re going to drill down into some more specific pros and cons for our two most popular gasket types, silicone, and EPDM. There are several types of silicone and EPDM products out there and what we’re going to cover are the food-grade versions of both products. We won’t get into the hardcore chemistry of what makes up each of these products but we will look at various properties and how they impact the distillation process.

Distilling Gaskets Comparisons

Alcohol stills are a fairly demanding environment, any material used to make them will have to come into contact with whatever chemicals are present in your wash along with the heat and slight pressure that comes from boiling said wash. Thankfully both silicone and EPDM  are fairly chemically resistant and heat resistant, silicone can handle temperatures up to 550 degrees Fahrenheit while EPDM can “only” tolerate up to 300 degrees Fahrenheit. Your still should never get anywhere close to either max temperature so both remain viable options.

Both EPDM and silicone share a weakness, they are prone to oil and hydrocarbon absorption and can swell or have a lower service life for certain applications. This may sound like a dealbreaker for ethanol production since ethanol is a carbon-based molecule but it’s not a huge concern in this application. Ethanol behaves differently than oils and both silicone and EPDM can be safely used in its production.

Most flexible materials will degrade over time when exposed to heating and cooling cycles so replacing your gaskets should be part of your preventative maintenance schedule. Whenever you take your still apart for cleaning you should be inspecting your gaskets and replacing any that look worn. It’s always very frustrating when your production schedule gets thrown off because you didn’t replace an inexpensive part when you’re already shut down.

One of the main differences between the two materials is that EPDM gaskets are more resistant to abrasion and wear than silicone and can be used in more dynamic applications. This makes EPDM a clear winner for valve seals or any other application where the seal is contacting a moving part.

The copper distillation equipment being displayed

Choose Your Distillation Gasket

So there you have it, these are the main differences between EPDM and silica gel in the distillation world. They all have many other wonderful properties, but they don't affect the distillation process. UV resistance is great, but most of us don't store our equipment outside. There's still a lot to discuss about gaskets and all distillates, so get in touch with us, or if you have any questions, we'll be happy to point you in the right direction. Contact Kate and my email: kate@degonget.com