ARSD 61:08:05:07. Low-water fuel cutoffs required

Each automatically fired steam or vapor system boiler shall be equipped with one or more automatic low-water fuel cutoffs wired in series with the limit controls. It shall be located to cut off the fuel supply automatically when the surface of the water falls to the lowest safe water line. Steam boilers equipped with the electrode type of low-water fuel cutoff are required to have an additional float-operated low-water fuel cutoff.