How to choose O-rings based on the material?

O-rings have become indispensable in many manufacturing industries, and almost any device you buy nowadays has one installed. Due to their cost, simple production and easy installation, they have found their way into a lot of everyday products, such as cars and engines.

Their function and versatile use have made them one of the most utilized products in the modern industry. Many of them are made of rubber, or elastic polymer, however, there are other materials you should explore as well. Many O-ring manufacturers are sealing products used in brewing, aerospace industry, automotive industry and so on. But, let’s see what other materials you can utilize.

Nitrile

Temperature: O-rings made of nitrile can go between -53° and 153°.

Appropriate for: the general purpose is to seal, for instance, you can use it to seal petroleum oils, water, and some other hydraulic liquids. This material is excellent because it provides high resistance.

Lacks: while it is excellent with liquids such as water and oil, Buna-N has problems with automotive brake fluids, ketones, phosphate ester hydraulic fluids, and nitro and halogenated hydrocarbons. Even though it is ozone and weather resistant, it’s not 100% sure.

Applications: Nitrile O-rings have a limited temperature and resistance requirements.

Ethylene propylene rubber

Temperature: it can range between -53° and 153°.

Appropriate for: Skydrol, a hydraulic liquid, it has a noxious smell and can irritate skin. This material also features some corrosive properties and can damage the equipment. We already mentioned that EPR O-rings work well with Skydrol and other hydraulic liquids, but they can also be combined with water, steam, silicone oils, brake fluids, and alcohols.

Lacks: same as nitrile, EPR isn’t perfect for a wide range of applications because of wear and tear issues.

Use: the aerospace industry uses them quite often in their hydraulic pumps.

Fluorocarbon (Viton)

Appropriate for: Viton can handle the number of applications, especially sealing jobs that involve all types of movement. It is also used for petroleum oils, silicone fluids and gases, acids, and some halogenated hydrocarbons.

Lacks: this material is not intended for Skydrol, amines, esters, and esters will low molecular weight and hot hydrofluoric acids.

Application: Viton O-rings are quite versatile, and it’s used in various automotive, appliances and chemical processing industries.

Neoprene


Appropriate for: neoprene is used to seal refrigerants in refrigeration and air conditioner units, also petroleum oils, and mild acid resistance ester lubricants.

Lacks: the final neoprene O-rings are often constructed with lead-based agents, which can be dangerous for human health. Also, some people are allergic to basic neoprene. When we are talking about the functional sense, it is not very resistant to petroleum lubricants and oxygen.

Application: it is used in refrigeration units of air conditioning systems.

Temperature: it ranges between -53° and 153°.

Polyurethane

Temperature:  between -53° and 153°

Appropriate for: it features abrasion and extrusion resistance, as well as toughness.

Lacks: high compression and heat aren’t suitable for polyurethane.

Application: these types of O-rings are used for hydraulic fittings, cylinders, and valves.

About the Author Robert Simpson