PEX-B is made using a “Silane” or “Moisture Cure” method of cross-linking, where links between the molecules of the Polyethylene polymer are formed after the extrusion process using a catalyst and by exposing PEX tubing to water (steam bath) which creates HDPE (high-density polyethylene).
PEX-B is a clear winner in terms of quality vs. PEX-A. It has been used for over 33 years with no known issues, given that a typical warranty for any other type of PEX is only 10-15 years. PEX-B manufacturers offer a 25-year warranty. PEX-B is also the only PEX able to withstand continuous hot water (+140 degrees) from recirculation pumps. All other PEX require a timer or limited exposure to hot water (+140 degrees). It also has a higher bursting pressure than PEX-A and a better resistance to oxidation – a very important factor for plumbing installations.
Highest chlorine and oxidative resistance
Highest bursting pressure.
No leaching chemicals from the manufacturing process.
High burst pressure.
Lowest dimensional tolerances variations.
Lower cross-linking ratio than PEX-A.