MrPEX Barrier PEX tubing is Cross-Linked Polyethylene (PEX-a) manufactured and listed to ASTM F 876/877 (CSA B137.5) and ICC-PMG, and certified by NSF (NSF-rfh). Tubing is rated by the Hydrostatic Stress Board of PPI (Plastics Pipe Institute) at: 160 psi at 73.4F; 100 psi at 180F;
80 psi at 200F. The oxygen barrier meet DIN 4726. Sizes 3/8-in. through 3/4-in. has a noise reduction barrier. MrPEX tubing is extremely flexible due to a very unique process. Molecules are oriented in a spiral fashion and cross-linked simultaneously during extrusion. Peroxide crosslinking (PEX-a) guarantees optimal tubing properties.