Standard John Guest fittings are FDA grey Acetal with Nitrile oring seal
Also available in white polypropylene when part number is followed by an asterisk” * ” . White John Guest fittings are made of polypropylene. They are developed for the water treatment industry to withstand caustic cleaning agents commonly used to flush out RO systems. The white John Guest fittings utilize an EPDM oring rather than Nitrile that is standard with the acetal style. Part number for this version ends with ” PP “, i.e. J4MC2PP and are the same price as the standard grey acetal.
For a cross reference of John Guest fittings part numbers to Portage Specialty part numbers click here