This Standard specifies requirements for the design, construction and testing of safety valves, liquid relief valves, liquid level gauges, blowdown valve, and other fittings for use on boilers and unfired pressure vessels, and their associated piping.It does not deal with the selection, operation, or application of valves and fittings, as these are dealt with in the Standard applying to the equipment to which the valves and fittings are to be connected, e.g. AS 1210, nor does it include requirements relating to safety fittings of a class or kind that are already the subject of a relevant Standard, e.g. -(a) Bourdon tube pressure and vacuum gauges . . . . . . . . . AS 1349;(b) bursting discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AS 1358;(c) fusible plugs for boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . AS 1732; and(d) bursting discs and bursting disc devices . . . . . . . . . . . . .ISO 6718.