Minnesota Legislature
Office of the Revisor of Statutes
Minnesota Administrative Rules
4715.2010 MINIMUM REQUIRED AIR GAP.
Subpart 1.
Measurement.
The minimum required air gap shall be measured vertically from the lowest end of a potable water outlet to the flood rim or line of the fixture or receptacle into which it discharges.
Subp. 2.
Requirement.
The minimum required air gap shall be twice the effective opening of a potable water outlet unless the outlet is a distance less than three times the effective opening away from a wall or similar vertical surface in which cases the minimum required air gap shall be three times the effective opening of the outlet. In no case shall the minimum required air gap be less than shown in subpart 4.
Subp. 3.
Effect of walls, ribs, and similar obstructions.
Side walls, ribs, or similar obstructions do not affect air gaps when spaced from inside edge of 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.
Vertical walls, ribs, or similar obstructions extending from the water surface to or above the horizontal plane of the spout opening require a greater air gap when spaced closer to the nearest inside edge of spout opening than specified in this subpart. 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 wall.
Subp. 4.
Minimum air gaps for plumbing fixtures.
| Minimum Air Gap | ||
| Fixture | When Not Affected By Near Wall (1) (Inches) | When Affected By Near Wall (2) (Inches) |
| Lavatories and other fixtures with effective opening not greater than 1/2 inch diameter | 1.0 | 1.50 |
| Sink, Laundry trays, gooseneck bath faucets and other fixtures with effective openings not greater than 3/4 inch diameter | 1.5 | 2.25 |
| Over rim bath fillers and other fixtures with effective openings not greater than 1 inch diameter | 2.0 | 3.0 |
| Drinking water fountains | 1.0 | 1.50 |
| Effective openings greater than one inch | 2x diameter of effective opening | 3x diameter of effective opening |
History:
L 2007 c 140 art 6 s 15; art 13 s 4
Published Electronically:
May 14, 2012
Official Publication of the State of Minnesota
Revisor of Statutes