This standard specifies that gas appliances that use city gas or liquefied petroleum gas (hereinafter referred to as gas) with a gas pressure of 3.23 kPa or less and gas valves should be connected indoors using a 9.5 mm rubber tube or a 9.5 mm or less reinforced gas hose. Specifies quick fittings for general household use (hereinafter referred to as fittings).