Why EPDM Should Not Be Used With Oil-Based Fluids

EPDM is a reliable hose material in water-based systems, but it should never be used with oil-based hydraulic fluids. Petroleum oils are highly aggressive toward EPDM rubber and cause it to swell, soften, and lose structural integrity. This deterioration happens quickly once oil comes into contact with the hose, which leads to leaks, blistering, and premature hose failure.

Because of this incompatibility, EPDM is primarily used in water-based coolant systems, glycol mixtures, and low-pressure environmental applications. In these environments, EPDM offers excellent resistance to heat, steam, and weathering. Its ability to handle temperature variation makes it ideal for coolant lines, but the same properties that perform well with water-based fluids become a weakness when exposed to oil.

For hydraulic systems that use oil-based fluids, materials like nitrile (NBR) or HNBR are far better suited. These compounds maintain their structure under oil exposure and deliver long-term durability under pressure. Pairing compatible hose materials with premium fittings ensures leak-free performance. Titan Fittings offers stainless steel JIC adapters, ORB O-ring fittings, and NPT adapters that integrate perfectly with oil-rated hoses. Explore Titan’s full line of hydraulic fittings and adapters to build a system matched to the right hose and fluid.