Abstract： ASME A112.1.2:2012 pdf download.Air Gaps in PlumbingSystems (For PlumbingFixtures and Water-Connected Receptors). receptor (see Figs. 1 and 2). backflow: the flow of water or other liquids into the distributing pipes of a potable supply of...

ASME A112.1.2:2012 pdf download.Air Gaps in PlumbingSystems (For PlumbingFixtures and Water-Connected Receptors).

receptor (see Figs. 1 and 2).

backflow: the flow of water or other liquids into the distributing pipes of a potable supply of water from any

source or sources other than the intended source. Backsiphonage and backpressure are types of backilow.

backflow connection or condition: any arrangement whereby backilow can occur.

backflozv prevention device: a device or assembly (combination of devices) designed to prevent backflow.

critical level: the level at which backsiphonage will not occur, including any required factor of safety.

critical level mark: the manufacturer’s designated critical level.

effective opening: the smallest cross-sectional area in a faucet, device, or a supply pipe through which water

flows to an outlet. If two or more lines supply one outlet, the effective opening shall be the sum of the

cross-sectional areas of the individual lines or the area of the outlet, whichever is smaller.

NOTE: To illustrate the practical use of the term “effective opening,” refer to Fig. 1. With ordinary plumbing

supply fittings, the minimum cross-sectional area usually occurs at the seat of the control valve, B; but, in

other cases, it may be at the point o discharge (spout) or at the inlet to the control valve, X.

elevation: the air gap—related term applied to drinking fountain nozzles.

flood-level rim: the top edge of the receptor from which water will flow out of the receptor (an overflow opening is not considered a flood-level rim).

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