The poly steel pipe is the kind of composite pipe which is made of galvanized steel bonded in the middle with Polyethylene ( HDPE) both as outer and inner layers. Poly steel Pipe possesses all the good characteristics of the PE-lined galvanized steel pipe and improves the outer surface anti-erosion ability. Therefore, it not only can be apply construction use, but can be used as under-ground pipe. It has a perfect appearance and has the function to improve the ability of heat preservation. The size available is from 1/ 2" ( 15mm) to 4" ( 100mm) . Specification: BS 1387-1985, CJ/ T136-2007, JWWA K116: 2004