ASME A112.1.2 pdf download

ASME A112.1.2 pdf download.Air Gaps in Plumbing Systems (For Plumbing Fixtures and Water-Connected Receptors).
The draft proposal was considered and revised. Copies of this revised report were distributed to interested firms and individuals in Industry for further criticism and comment. At the October meeting of the subcommittee, the comments received were carefully considered. The April 1940 dralt, which followed shorth was distributed to the members of Sectional Committee A40 for discussion. Certain changes were recommended, as well as the addition of two sections covering water inlets to tanks having overflows and drinking fountain bubblers. These were incorporated in the revised draft d,fled May 1940- Copies of this draft were ditrihuted to the members of the sectional committee and to a group of more than 100 health supervisory officials, plumbing inspectors, state plumbing associations, and others. The received recommendations prompted another revision, which was reviewed by the members of Subcommittee 12. The changcs and refinements made were incorporated, and a final revision dated July 1941 was approved by letter ballot vote of the sectional committee.
Following approval by the sectional committee and the sponsor organizations, the draft was transmitted to the American Standards Association (now known as the American National Standards Institute) for approval and designation as an American Standard. This designation was given in January 1942.
In 1958, the functions of Sectional Committee A40 pertaining to Standards for Plumbing Equipment were transferred to Standards Committee Al 12, and this Standard on Air Gaps in Plumbing Systems was assigned to Panel I. Panel I recommended the Standard’s reaffirmation on Apnl 18, 1972. Standards Committee A112 concurred in this recommendation on June 28, 1972. The American National Standards Institute approved this reaffirmation on January 23, 1973 and designated it Al12.l.2-l973. The document was reaffirmed in 1989, revised in 1990. and revised again in 2004,
(b) Connect the inlet(s) of the faucet or device to a vacuum source. The vacuum shall be measured at the inlet of the faucet or device.
(c) A means to change the water level in the container relative to the outlet of the faucet or device shall be provided.
(d) Start the test with the water level at the mounting surface of the faucet or device.
(e) With the faucet or device fully open from its inlet(s) to point of discharge to atmosphere, apply a vacuum of 635 mm Hg (25 in. Hg) to the inlet(s). Backsiphonage at this time is cause for rejection.
(f) The water level shall slowly be brought closer to the discharge outlet of the faucet or device until the level at which backsiphonage occurs. At this point, record the water level. The distance between the water level and the lowest point on the discharge outlet of the faucet or device shall be measured and recorded
(g) Return the faucet or device to atmospheric conditions.
(h) Starting with the water level higher than where backsiphonage occurred, apply a vacuum to the inlet(s) of 635 mm Hg (25 in. Hg). Slowly lower the water level until the backsiphonage stops. Maintain the vacuum for another I mm to be sure no more water is being drawn into the discharge outlet of the faucet or device. At this point, record the water level. The distance from the water level and the lowest point on the discharge outlet of the faucet or device shall be measured and recorded.
(1) The larger of the two distances measured and recorded shall be considered the critical air gap of the faucet or fitting.
fj) Repeat this test for another two sequences to confirm the measured and recorded critical air gap.
(k) For faucets and devices with a critical level mark, confirm that the mark is at a level that is at or above the highest water level recorded in determining the critical air gap.
NOTE; Faucets or devices that can be installed and have a near- wall effect jscc Table 1, Notes (1) and (2)1 shall be tested with the discharge outlet of the faucet or device against one wall of the test container.
2.4.2 Backsiphonage. With the water level at the critical level mark on the faucet or device or at the mandatory levels of Table I when the faucet or device has no mark, apply a vacuum of 635 mm Hg (25 in. fig) to the inlet(s) of the faucet or device. Any indication of water at the inlet(s) shall be cause for rejection.