The invention relates to a multilayer plastic pipe (1), preferably for use in heating systems. The multilayer pipe comprises an inner core (2) and a barrier layer (6) surrounding the core and preventing oxygen diffusion through the multilayered pipe. The core (2) is made of a material having viscoelastic properties, preferably cross-linked polyethylene, and the barrier layer (6) is surrounded by an outer layer (8) of a material having adhesive properties. The invention also relates to the use of a multilayer pipe for providing pipe couplings.
Pipe or tubing of crosslinked polyethylene ("PEX") containing less than 2% by wt. carbon black provides improved resistance to oxidizing agents such as chlorine and hypochlorous acid in water. The pipe may be further protected with a thin tubular core (inner layer) of high density polyethylene or chlorinated polyethylene. The pipe may optionally have an oxygen barrier layer, such as poly(ethylene-co-vinyl alcohol) ("EVOH"), contiguously disposed radially outward from the carbon-containing PEX layer. The pipe is suitable for potable water applications and for hot water radiant heating systems.
A multilayer PEX pipe having improved resistance to oxidizing agents in water. The pipe has a thin tubular core (inner layer) of high density polyethylene and an outer layer of crosslinked polyethylene. The pipe may optionally have an oxygen barrier layer, such as poly(ethylene-co-vinyl alcohol) ("EVOH"), contiguously disposed radially outward from the PEX layer. The pipe is suitable for potable water applications and for hot water radiant heating systems.
