Rubber Compounds & Compatibility

Buna - Nitrile - NBR

Nitrile is probably the most common rubber sealing material used. Mostly because of cost, but also because of its resistance to lubricants and greases. Nitrile generally holds up well to mineral oil-based lubricants and greases, hydraulic fluids, aliphatic hydrocarbons, silicone oils and hot water to 175°F (80°C). Nitrile is not particularly effective with aromatic and chlorinated hydrocarbons, fuels with high aromatic content, ozone and aging.

EPDM - Ethylene-Propylene

EPDM is an excellent choice for hot water (300°F / 100°C) and steam (350°F / 175°C) applications. It also exhibits good resistance to detergents, potassium hydroxide solutions (potash), sodium hydroxide (lye), silicone oil and greases, polar solvents and diluted acids. The wide range of compatibility makes EPDM a great choice for almost any sealing application; however it does not stand up well to mineral oil products.

Silicone - VMQ

Silicone rubber is best suited in applications that require a wide temperature range (-65°F / -55°C - 390°F / 200°C), without the need for tear and abrasion resistance. However, the materials used to make silicone are generally harmless to ingest, so the typical silicone compound is inherently FDA compliant. Silicone does not hold up well to fuels, aromatic mineral oils, steam, silicone oil, acids or alkalis.

Viton® - FKM

FKM is well known for its high chemical and fuel resistance. It holds up well in mineral oil, aliphatic, aromatic and chlorinated hydrocarbons. It also has excellent high temperature properties (390°F / 200°C) but is not recommended for hot water or steam applications. FKM also does not withstand polar solvents, glycol-based brake fluids or low molecular weight organic acids (formic. acetic, propionic, lactic, n-butyric and isobutyric).

Viton is a registered trademark of Dupont Performance Elastomers.