A Plumbing Materials, Equipment, Use Restrictions and Applicable Standards

Section 885 Section 890.APPENDIX A Plumbing Materials, Equipment, Use Restrictions and Applicable Standards Section 890.TABLE C Minimum Air Gaps for Plumbing Fixtures Minimum Air Gap (Inches) When Not Affected by Near Wall 1 When Affected by Near Wall 2 Lavoratories and other fixtures with effective opening not greater than ½ inch diameter. 1 1½ Drinking water fountains, single orifice not greater than 7 / 16 (0.437) inch diameter or multiple orifices having total area of 0.150 square inches (area of circle 7 / 16 inch diameter). 1 1½ Sink, laundry trays, goose neck bath faucets and other fixtures with effective opening not greater than one inch diameter. 1½ 2¼ Stills, sterilizers and other appliances, fixtures, devices and water and waste connections used for preparation of sterile material. 2 3 Over rim bath fillers and other fixtures with effective openings not greater than one inch diameter. 2 3 Effective openings greater than one inch. 2 X Diameter of effective opening 3 X Diameter of effective opening 1 Side walls, ribs or other 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. 2 Vertical walls, ribs or similar obstructions extending from the water surface or to 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 Footnote 1 above. 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.