One must differentiate between polyester urethane (AU) and polyether urethane (EU). AU type urethanes exhibit better resistance to hydraulic fluids. Polyurethane elastomers, as a class, have excellent wear resistance, high tensile strength and high elasticity in comparison with any other elastomers. Permeability is good and comparable with butyl rubber.
Both o-rings and gaskets can be made from EPDM materials.
Names: Polyurethane, Millable Polyurethane, AU, EU
|ASTM D1418 Designation||AU, EU|
|ASTM D2000/SAE J200 Type, Class||BG|
|Hardness (Shore A)||40-90|
|Standard Min Temp.||-30°F (-34°C)|
|Max Temp.||175°F (79°C)|
Pure aliphatic hydrocarbons (propane, butane, fuel)
Mineral oil and grease
Silicone oil and grease
Water up to 125°F(50°C) (EU type)
Ozone and aging resistance
Ketones, esters, ethers, alcohols, glycols
Hot water, steam, alkalis, amines, acids
Disclaimer: These are general guidelines only. All materials should be tested in your application.