Historical
IAPMO PS 66-2000
Dielectric waterway fittings
This standard covers insulated, dielectric waterway fittings in sizes 1/2" (12.7 mm) thru4" (101.6 mm) and configurations include male nominal pipe threads (MNPT), groovedends and plain ends. This standard covers definitions, general requirements, in additionto general description on materials used and the method of marking and identification.
International Association of Plumbing and Mechanical Officials [iapmo]