ASME A112.1.2:2012 pdf free download
ASME A112.1.2:2012 pdf free download.AIR GAPS IN PLUMBING SYSTEMS (FOR PLUMBING FIXTURES AND WATER-CONNECTED RECEPTORS)
NOTES:
(1) Side walls, ribs, or similar obstructions do not affect the air gaps when spaced from the inside edge of the spout opening a distance greater than three times the diameter of the effective opening for a single wall or a distance greater than four times the diameter of the effective opening for two intersecting walls (see Figs. 2 and 3).
(2) Vertical walls, ribs, or similar obstructions extending from the water surface to or above the horizontal plane of the spout opening require greater air gaps when spaced closer to the nearest inside edge of the spout opening than specified in Note (1). The effect of three or more such vertical walls or ribs has not been determined. In such cases, the air gap shall be measured from the top of the walls.
NOTE: The definition of “flood-level rim” is based on a fixture or receptor with reasonably level edges. It is recognized that certain fixtures or receptors may be provided with uneven edges. In such cases, the equivalent of flood-level rim shall be considered as the maximum water elevation possible with full flow of water from all water-supplied pipes discharging into the fixture or receptor. Obviously, in such cases, the flood-level rim or its equivalent is not capable of simple measurement in the field.
free area: the area created between a near wall and the faucet or fitting when the distance between the wall and the outlet of the faucet or device is three times the diameter of the effective opening for a single wall or a distance four times the diameter ofthe effective opening for two intersecting walls.
The following requirements of minimum required air gaps shall apply to plumbing fixtures in general use. It is recognized that the actual water level in a receptor may rise higher than the flood-level rim and a factor of safety has been applied to compensate for this higher level.