This document specifies requirements for flow control devices that can be connected by the user either directly, by means of a probe or a gas-specific connector, or indirectly by means of a low-pressure hose assembly conforming with ISO 5359 to: a)    a terminal unit conforming with ISO 9170-1 of a medical gas pipeline system conforming with ISO 7396-1:2016; b)    the pressure outlet of a regulator conforming with ISO 10524-1:2018; or c)    to the pressure outlet of a valve integrated pressure regulator (VIPR) conforming with ISO 10524-3 (see 5.2 gas inlets). This document applies to the following types of flow control devices (FCDs): a)    flowmeters; b)    flowgauge FCDs; and c)    fixed orifice FCDs. NOTE       Flow control devices that are classed as medical electrical equipment can be subject to additional requirements of IEC 60601-1. This document applies to flow control devices for the following gases: –    oxygen; –    oxygen 93 %; –    nitrous oxide; –    medical air; –    carbon dioxide; –    oxygen/nitrous oxide mixture 50/50 (% volume fraction); –    oxygen-enriched air; –    helium; –    xenon; and –    specified mixtures of the gases listed above. NOTE – Flow control devices can be available for other gases. This document does not apply to flow control devices that are: a)    for use with gases for driving surgical tools; b)    an integral part of a regulator (see ISO 10524-1:2018); or c)           an integral part of a valve with integrated pressure regulator (VIPR) (see ISO 10524-3).