Compounds of natural have been used for decades for gate valves and flange gaskets

There are numerous potential sources of contamination in potable water systems, not least of which is contact with the components comprising these systems. On its journey from the source to the tap, water typically passes through miles of pipe and various mechanical devices such as pumps, meters, and valves, all of which require seals.
Because of their resilient properties, elastomers account for a large portion of these materials. Compounds of natural , styrene butadiene , and acrylonitrile butadiene rubbers and Chloroprene (Neoprene) have been used for decades for pipe seals, gate valves, flange gaskets and O-rings.
Ethylene propylene diene rubber , with its superior hydrolytic stability and resistance to chloramines, is becoming more widely used in these applications. Even fluoroelastomers are being used in gaskets for CPVC piping, where leaching of plasticizers from other elastomers can compromise the piping.
Rubber-bound fiber sheet finds application in a variety of flange gaskets where, because of limitations on size or gasket stress, homogenous elastomers cannot be used. Polytetrafluoroethylene based materials are used in applications where chemical resistance or high levels of purity are required. Glass fiber reinforced epoxy is widely used in gaskets where mating flanges must be electrically isolated .