scope:

This Standard specifies the requirements for polyethylene spigot fittings and socket fusion fittings (hereafter referred to as fittings) intended to be used with polyethylene pipes for the supply of town gas and liquefied petroleum gas.

The fittings can for example be in the form of couplers, saddles, equal and reduced tees, reducers, elbows, bends, or end caps.

The maximum operating pressure (MOP) of the polyethylene pipes and pipe-fittings for the supply of gaseous fuels conforming to JIS K 6774, JIS K 6775-1 and JIS K 6775-3 and their joints, and joints with components of polyethylene or other materials is based on the design stress determined from the compound minimum required strength (MRS) divided by C factor [overall service (design) coefficient], and taking into account rapid crack propagation (RCP) requirements.

NOTE The International Standards corresponding to this Standard and the symbol of degree of correspondence are as follows.

ISO 4437-1 : 2014 Plastics piping systems for the supply of gaseous fuels - Polyethylene(PE) - Part 1 : General

ISO 4437-3 : 2014 Plastics piping systems for the supply of gaseous fuels - Polyethylene(PE) - Part 3 : Fittings (Overall evaluation : MOD)

In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standards and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/IEC Guide 21-1.