1. If there is one near wall, and the distance between that near wall and the closest edge of the supply pipe/spout is greater than 3 times the diameter of the supply pipe/spout, then the minimum air-gap is 2 times the diameter of the supply pipe/spout.
2. If there is one near wall, and the distance to the closest edge of the supply pipe/spout is less than 3 times the diameter of the pipe/spout, then the minimum air-gap is 3 times the diameter of the supply pipe/spout.
3. If there are 2 near walls, and the distance between the near wall(s) and closest edge of the supply pipe/spout is greater than 4 times the diameter of the supply pipe/spout, then the minimum air-gap is 2 times the diameter of the supply pipe/spout.
4. If there are 2 near walls, and the distance to the closest edge of the supply pipe/spout is less than 4 times the diameter of the supply pipe/spout, then the minimum air-gap is 3 times the diameter of the supply pipe/spout.
It has been determined that 2 or more near walls generally have little effect on the need to increase the air-gap to more than 3 times the diameter of the supply pipe/spout.
Note: See the following sketches as examples of an air-gap with pipe/spouts terminating above the flood level rim of the receptacle/fixture, of an air-gap with pipe/spouts terminating below the flood level rim of the receptacle/fixture and of an air-gap with pipe/spouts when terminating by one near wall.
A-382.41 (5)-1. Air-gap with pipe/spout(s) above flood level rim of receptacle/fixture.
WATER SUPPLY AIR-GAP ASME 112.1.2
A-382.41 (5)-2. AIR-GAP WITH PIPE/SPOUT(S) BELOW FLOOD LEVEL RIM OF RECEPTACLE/FIXTURE.
*Any situation may be subject to an alternate approval.
1 If less than 15 pounds steam or 30 pounds water and nontoxic chemicals.
2 If greater than 15 pounds steam or 30 pounds water and toxic chemicals.
3 Requires backflow protection even if there is a plain end spout.
4 Requires separate water supply terminating without a hose thread, or the manufacturer must provide a bleed device to connect to the janitor sink faucet spout.
5 Or, provide bottled water conversion unit.
6 For outlets other than the required ASSE 1019 hydrants.
7 If provided with hose threads or serrated nipple.
8 Faucet meeting ASME A112.18.1M that includes backflow protection requirements.
9 Hydrants that bleed into the ground and hydrants that are flush with the grade are prohibited.
A-382.41 (5) (f)-1. CROSS CONNECTION CONTROL ASSEMBLY INSTALLATION.
A-382.41 (5) (f)-2. CROSS CONNECTION CONTROL ASSEMBLY INSTALLATION.
A-382.41 (5) (f)-3. CROSS CONNECTION CONTROL ASSEMBLY INSTALLATION.
A-382.41 (5) (f)-4. CROSS CONNECTION CONTROL ASSEMBLY INSTALLATION.
A-382.41 (5) (f)-5. CROSS CONNECTION CONTROL ASSEMBLY INSTALLATION.
A-382.50 (3) (b) 5.
OPTIONS FOR TEMPERATURE CONTROL IN HEALTH CARE FACILITIES. The following sketches provide options for fail safe installations at the bathing and shower fixture and temperature control at handwashing fixtures.
A-382.51 (3) MOBILE HOME SITES AND PARKS. Mobile home building sewer and water service connections.