Understanding Oil Resistant Gaskets
When it comes to oil resistant gaskets, there are many different kinds, and of course the best kind for your project depends entirely upon the application. Many of these gaskets are made of non-asbestos or rubber, so it is essential that you understand when non-asbestos gaskets are OK to use and when you simply need a rubber one. In most cases, you will want to use rubber rather than non-asbestos, which is a harder material requiring more torque to seal properly. Non-Asbestos is a good material where there is lots of pressure.
Usually oil resistant gaskets are cut from larger sheets of the material. They can be cut to any size, so what you are really looking for when selecting the right one is a list of properties of the material. There are several kinds of rubber that have oil resistant properties, and each of these rubbers also have other characteristics that make it perfect for very specific uses in which oil resistance isn’t the only concern. Here are some of the most popular types of rubbers used:
Neoprene – This type of rubber is a good general purpose rubber with Moderate Oil and Ozone resistance. Neoprene can be used generally for unrefined or crude oil. It probably offers least oil resistance of all the common material options for use with oil. Neoprene’s greatest value is that it is the most economical of all the sheet rubber options. Gaskets that are made of neoprene tend to age better because of its ozone resistance quality. One downside is that the tensile strength is probably lower than that of some other types of oil resistant rubbers. Also this type of gasket doesn’t do particularly well in extremely low temperatures.
Nitrile (Buna N) – This type of rubber offers very good oil resistance and can be used for a good variety of refined oils. Nitrile is the most commonly used material for sealing oil. It is also available as a Cork and Nitrile combination. This material is commonly used in the oil field and storage tanks. This material is very economical as well. While Nitrile has better oil resistance characteristics than Neoprene it doesn’t have the same ozone resistance.
Genuine DuPont Viton® – This is probably your best option. This material is resistant to the highest refined fuels and oils. This material will also withstand Extreme temperatures. (-17° to 400° F) making this an ideal material for use in areas with extreme high and low temperatures. Genuine DuPont Viton® is also very resistant to many chemicals which makes it the best option for use with sour gas which would quickly attack and disintegrate Neoprene or Nitrile. Viton is ozone friendly and also is resistant to many, many different chemical applications. Although Viton is certainly not as economical as Neoprene or Nitrile it certainly has many qualities that make it one of your best sealing material options both short and long term.
Silicone – This is one of the most common types of rubber, and as such, you will find many oil resistant gaskets that are made from it. Silicone also has good temperature range but is not as resilient to the higher grade oils as Viton. Silicone is a little less expensive than Genuine DuPont Viton® but again isn’t quite as resistant.
Non-Asbestos – As stated above Non-asbestos is a great gasket material for use where there is greater pressure. This material is an aramid fiber that is bound together with a Nitrile binder. This material is very common in the oil field.