Automatic Low-Water Fuel Cutoff and/or Water-Feeding Device

Automatic Low-Water Fuel Cutoff and/or Water-Feeding Device 1. Each automatically fired and unattended steam or vapor system boiler shall be equipped with an automatic low-water fuel cutoff so locates as to automatically cut off the fuel supply when the surface of the water falls to the lowest safe water line. If a water-feeding device is installed, it shall be so constructed that the water inlet valves cannot feed water into the boiler through the float chamber and so located as to supply requisite feedwater. The lowest safe water line should be not lower than the lowest visible part of the water glass. Such fuel or feedwater control device may be attached direct to a boiler or to the tapped openings provided for attaching a water glass direct to a boiler provided that for low- pressure boilers such connections from the boiler are nonferrous tees of Y's not less than 1/2-inch pipe size between the boiler and the water glass, so that the water glass is attached direct and as close as possible to the boiler; the straightaway tapping of the Y or tee to take the water glass fittings, the side outlet of the Y or tee to take the fuel cutoff or water-feeding device. 2. The ends of all nipples shall be reamed to full-size diameter. 3. Designs embodying a float and float bowl shall have a vertical straightaway valve drain pipe at the lowest point in the water-equalizing pipe connections by which the bowl and the equilizing pipe can be flushed and the device tested. A coil type boiler or a water tube boiler with heat input greater than 400,000 BUT/HR requiring forced circulation, to prevent overheating of the coils or tubes, shall have a flow sensing device installed in the outlet piping, in lieu of the low water fuel cutoff required in this item, to automatically cut off fuel supply when the circulating flow is interrupted.