D.C. Mun. Regs. tit. 25, r. 25-B1409
Current through Register Vol. 71, No. 49, December 6, 2024
If an air gap is not provided as specified in section 1405, a double check valve with an intermediate vent preceded by a screen of not less than one hundred (100) mesh to twenty-five and four tenths millimeters (25 4 mm) (100 mesh to 1 inch) shall be installed upstream from a carbonating device and downstream from any copper in the water supply line.
A single or double check valve attached to the carbonator need not be of the vented type if an air gap or vented backflow prevention device has been otherwise provided as specified in section 1408.1.
D.C. Mun. Regs. tit. 25, r. 25-B1409