Instantor Pex-Al-Pex is a multilayer pipe constructed with a double inner and outer layer of Silane method crosslinked polyethylene PE-xB, bound by quality adhesive to a longitudinally TIG butt welded. WRAS Approved, NASI certified to EN ISO 21003. Cost effective pipe system. Combined advantages of metal and plastic pipe. Light weight, flexible and maintains shape. Excellent heat preservation. WRAS Approved, NASI certified to EN ISO 21003. Cost effective pipe system. Combined advantages of metal and plastic pipe. Light weight, flexible and maintains shape. Excellent heat preservation.