North Dakota Administrative Code › Title 33.1 - Department of Environmental Quality › Article 33.1-14 - NORTH DAKOTA BOILER RULES › Chapter 33.1-14-03 - GENERAL REQUIREMENTS › Section 33.1-14-03-07 - Automatic low-water fuel cutoff or water-feeding device

Current through Supplement No. 393, July, 2024
1. Each automatically fired steam or vapor
				system boiler must be equipped with an automatic low-water cutoff located to
				automatically cut off the fuel supply when the surface of the water falls to
				the lowest safe waterline. For other than electric and miniature boilers, each
				automatically fired steam or vapor system boiler must be equipped with at least
				two low-water fuel cutoffs, one of which must be readily testable. One
				low-water fuel cutoff must be set to function ahead of the other. Functioning
				of the lower of the controls shall cause safety shutdown and lockout. The
				manual reset may be incorporated into the lower cutoff control. Where a reset
				device is separate from the low-water fuel cutoff, a means shall be provided to
				indicate actuation of the low-water fuel cutoff. The manual reset device may be
				of the instantaneous type or may include a time delay of not more than three
				minutes after the fuel has been cut off. A system may incorporate a time delay
				component with the low-water fuel cutoff device to prevent short cycling. A
				time delay must not exceed the manufacturer's recommended timing, or ninety
				seconds, whichever is less. A high-pressure boiler regularly attended by a
				full-time operator is not considered as automatically fired, and is not
				required to be equipped with low-water fuel cutoffs. For other than electric
				boilers, the primary low-water fuel cutoff for low pressure steam boilers must
				be a float type that can be readily tested.
2. If a water-feeding device is installed, it
				must be constructed so that the water inlet valve cannot feed water into the
				boiler through the float chamber and located to supply requisite feedwater. The
				lowest safe waterline should not be lower than the lowest visible part of the
				water glass.
3. Such fuel or
				feedwater control device may be attached directly to a boiler or to the tapped
				openings provided for attaching a water glass directly to a boiler, provided
				that for low pressure boilers such connections from the boiler are nonferrous
				tees or Ys not less than one-half-inch [12.7 millimeter] pipe size between the
				boiler and the water glass, so that the water glass is attached directly and as
				close as possible to the boiler; the straight tapping of the Y or tee to take
				the water glass fittings, and the side outlet of the Y or tee to take the fuel
				cutoff or water-feeding device. The ends of all nipples must be reamed to
				full-size diameter.
4. Designs
				embodying a float and float bowl must have a vertical straight drainpipe at the
				lowest point in the water equalizing pipe connections by which the bowl and the
				equalizing pipe can be flushed and the device tested. This drainpipe and
				connections must be not less than national pipe standard (NPS) three-quarters
				inch.
General Authority:
NDCC 23.1-16
Law Implemented:
NDCC
					 23.1-16