PE-RT Potable Water Pipe

Polyethylene of raised temperature (PE-RT) pipes are designed to carry the benefits of PEX (crosslinked polyethylene) pipes, without the drawbacks associated with crosslinking. They are manufactured with a high density polyethylene resin that incorporates large co-monomers into the chain structure. These co-monomers cannot be incorporated into the crystal structure and thus create amorphous polymer segments that allow the polymer to form tie chains connecting the crystal structure. This structure gives the pipe extra strength and allows it to be used for hot water applications. PE-RT pipes use the same fittings as PEX pipes, and typically can be used for applications where PEX is specified, but they also have the ability to be thermally fused. Since PE-RT pipes are not crosslinked they are also recyclable. While these pipes are chlorine resistant, they rely on antioxidants to slow the rate of degradation. AWWA C901-17 requires PE-RT tubing to have a material designation code of PE4710, similar to HDPE pipes. 

PE-RT pipes and tubing sold in North America are generally offered in blue, white, and red. These pigments were not well disclosed and could add additional hazards not included in this Common Product (CP). Titanium dioxide was included as a representative pigment due to its widespread use as a pigment in polyethylene. While this CP covers PE-RT pipes used for potable water applications, PE-RT barrier tubing is also available. Barrier tubing contains multiple layers including a barrier layer composed of materials such as aluminum or ethylene vinyl alcohol (EVOH). Like PEX barrier tubing, this barrier allows the tubing to be used for radiant systems because it protects the metal components from corrosion by limiting oxygen permeation through the tube wall. Barrier tubing was beyond the scope of this CP but could introduce additional hazards and may also impact recyclability.