The proposed revision is to address a lack of information in the standard regarding the cross-linking of PEX manufactured using the silane process. Cross-linking of silane grafted polyethylene takes place after the extrusion process and is dependent on the geometry of the product, cross-linking time and temperature. The cross-linking process may also be delayed with the possibility that it may not be carried out at the same site where the pipe was originally extruded. Specific guidance needs to be added to the standard to properly address these concerns.
Keywordscrosslinked polyethylene; hydrostatic stress; PEX; PPI; pipe; pressure;;
Draft Under Development