Plypipe is a five-layer composite pipe, its inside and outside layers are made of High-Density, Cross-Linked or Medium Density Polyethylene ( HDPE, PEX or MDPE ) , tightly bonded with melt adhesive to the mid-layer of longitudinally overlapped-welded aluminum core of the pipe.  All layers are extruded by one step.

Plypipe's inside and outside layers are special PE, which is Hygienic, toxic-free and smooth, and its middle layer of AL is 100% of gas/oxygen tightness, giving it both advantages of metal and plastic pipe, but eliminating their own disadvantages.

Plypipe's fittings are specially designed for Plypipe and has been granted national patent.  Plypipe fittings are hi-corrosion and hi-pressure resistant, every sector of which parts strengthening into pipe is able to avoid leakage of gas and liquid, and is not affected by moving, connecting is easy.  the tighter of the nut, the tighter of fitting with pipe, all these assure to avoid gas and liquid leakage.