1)gostom composite pipe is a five-layer composite pipe, its inside and outside layers are made of hi-density, cross-linking polyethylene(pertor pex)tightly bonded with heating adhesive to the mid-layer of longitudinally overlapped-welded aluminum core of the pipe. All layers are extruded by one step.2)gostom composite pipe's inside and outside layers are of special PE, hygienic, toxic-free and smooth. Its middle layer of aluminium is 100% of gas/oxygen tightness, that gives it both advantages of metal and plastic pipe, but eliminates their own disadvantages3)corrosion free: The polyolefin family of plastics-hdpe and pex is renowned for it's toughness, long working life and resistance to deterioration in the most extreme environments. At normal temperature, it does not dissolve in any known solutions and is resistant against acid, alkali and salt of various kinds4)clean and healthy: Pap's clean, non-corroding plastic interior is resistant to deterioration in aggressive water conditions. You needn't worry about odor, color or taste problems arising because of the plumbing pipes in your home.5)gostom pipe's smooth inner plastic wall permanently resists scaling and mineral build-up, keeping water flow constant year after year. Unlike metal pipes, you won't see a reduction in flow area with pap. That means homeowners can enjoy a constant water pressure throughout the house, throughout the years.6)low expansion and contraction: Gostom pipe's aluminum core controls the amount of expansion and contraction in the pipe. In fact although composite pipe looks like a plastic pipe its expansion rate is very similar to copper's so you do not have to worry about building in costly and time consuming pipe offsets.7)gostom composite pipe can be installed in walls and ceilings or surface mounted. It can be supported horizontally or vertically on 8 foot centers because its stiffness and expansion rate is similar to copper's. It can be encased in concrete or buried underground without additional protection because its tough outer plastic layer resists chemicals and corrosive activity8)it is widely used in the transportation of hot and cold water, beverages, gases, heating liquid or shipbuilding pipe.