FRP Filters and Shofteners are made of composite material. Acomposite pressure vessel combines the unrivalled toughness of apolyethylene inner tank and the strength of a glass fiber reinforcedwith epoxy resin and wound on to a seamless composite liner thatmeans a strong tank that simply cannot rust. These compositepressure vessel tanks have been designed and constructed for theneeds of the commercial and industrial water treatment markets andheavy duty use.