Your Guide To The Best O-Ring Material
O-rings are some of the most widely used sealing materials. They are made from a wide variety of polymers called elastomers. A wide range of elastomers is used to manufacture o-rings that vary significantly in their properties. So selecting the right material is crucial to get the sealing right. The suitable o-ring for you will depend on the application environment and how well the material suits it.
Are you scratching your head over which material to buy? It’s not complicated. Read through this guide on the five most common o-ring materials in the market.
Viton/Fluorocarbon
Viton is a highly versatile material that can handle almost all kinds of process fluids. It can tolerate a wide range of temperature from -30 up to 400oC and has excellent resistance to chemical attack. Hence, they are used in all kinds of applications, including aircraft and automobiles.
Suitable for: All petroleum oils, acids, halogenated hydrocarbons, liquid and gaseous silicones
Not suitable for: Amines, esters, hot fluids like water, acids, and steam, Skydrol, and low molecular weight ethers
Neoprene
Neoprene is more suited to seal refrigerator and air conditioning units. They can withstand temperature as low as -40 to as hot as 450oF and provide excellent weather resistance.
Suitable for: Coolants, alcohol, oils and fats
Not suitable for: Petroleum oils, ketones, brake fluids
Nitrile/Buna-N
Nitrile is a popular o-ring material that is inexpensive and has excellent resistance to abrasive treatments and tears. It can operate within a temperature range of -35 to 250oF.
Suitable for: Petroleum oils, hydraulic fluids, and water
Not suitable for: Automotive brake fluids, phosphates, ketones, esters,
Silicone
Silicon is an odourless and non-toxic material that has several applications. It has excellent permeation resistance, and compression set resistance. Its temperature tolerance ranges between -120 and 450oF. However, it has low tensile strength and is more suitable for static applications.
Suitable for: Alcohols, vegetable oils, ozone, and oxygen
Not ideal for: Acids, ketones, brake fluids, and silicon oils
Ethylene Propylene Rubber (EPR)
Ethylene propylene is a high-grade rubber that is resistant to compression, weather, and water. These materials are widely used in the life science industry, such as pharmaceuticals, food, and medical industry.
Suitable for: Hydraulic fluids, Skydrol, steam, water, silicones, alcohols, brake fluids
Not suitable for: Petroleum oils
Polyurethane
Premium quality polyurethanes can withstand a temperature of -65 to 250o F and are often used in all kinds of mechanical seals, fluid transfer, and hydraulic systems.
Suitable for: Petroleum oils and hydrocarbons like ozone and oxygen
Not ideal for: Acids, water, ketones, and chlorinated hydrocarbons
So which material should you buy?
O-rings are an indispensable component of the sealing system. They not only seal a system but keep it working together. Hence, opting for the wrong material can prove disastrous, lead to seal failure, and negatively impact the equipment’s operation.
The above guide should help you decide which materials will suit your application and which ones will not. If you’re still not sure, contact a manufacturer or speak to an expert. Cheshire Seal and Components is a huge supplier of all kinds of seals and o-rings and an excellent service provider that you might want to reach out to.
