Diaphragm Materials


SOFT NATURAL RUBBER:
 Good in either wet or dry abrasive services, water, and some acids and alkalis. Soft natural rubber has one of the best abrasion resistances when strong chemicals are not present. Temperature 30 to 180°F

EPDM: (Ethylene Propylene Diene Monomer) The most popular general­purpose material. Excellent chemical resistance to a wide variety of corrosive elements including acids, caustics and hot water. It is abrasion resistant and good for high temperature services. EPDM has poor oil resistance. It is also satisfactory for intermittent steam sterilization. Temp 30 to 300°F

NEOPRENE: Widely used in wastewater applications. A good choice for general-­purpose chemical resistance where the media contains entrained oils. It also resists aldehydes, certain alcohols, fertilizers, explosives, petroleum, air, acids alkalis, and is abrasive resistant. Finally, in most cases is interchangeable with Buna­N (Nitrile) Rubber. Temperature –30 to 200°F

BUNA-N: (Nitrile Butadiene Rubber) is a generalpurpose oil resistant polymer known as nitrile rubber. It is a copolymer of butadiene and acrylonitrile. BunaN has a good solvent, oil, water, and hydraulic fluid resistance. It displays good compression set, abrasion resistance, and tensile strength. Nitrile should not be used in highly polar solvents such as acetone and methyl ethyl ketone, nor should it be used in chlorinated hydrocarbons, ozone, or nitro hydrocarbons. In most cases it is interchangeable with Neoprene. Max Temperature 275°F

BUTYL: A good choice for gases because it has a very low vapor and gas permeability. Also good for many acids and alkalis. Good for applications involving steam sterilization. Temperature ­20 to +250°F

TEFLON (PTFE) W/ EPDM BACKING: (Polytetrafluoroethylene) Good wear resistance, low coefficient of friction, and excellent corrosion resistance. Max us temperature 300°F

VITON: Offers exceptional resistance to oils, most chemicals and many solvents at elevated temperatures. It can be used in most applications involving mineral acids, salt solutions and chlorinated hydrocarbons. Viton is not recommended for ammonia, its derivatives or polar solvents, e.g. Acetone. ­20 to 300°F