NAC455C.266. Water level indicators.

     1. Outlet connections, except for damper regulators, feed water regulators, low-water fuel cutouts, drains, steam gauges or such apparatus that does not permit the escape of an appreciable amount of steam or water therefrom, must not be placed on the piping that connects the water column to the boiler. The water column must be provided with a valved drain of at least 3/4-inch pipe size, the drain to be piped to a safe location.

     2. A boiler is not required to be installed with a gauge cock.

     3. For all installations where the water gauge glass or glasses are more than 30 feet above the boiler operating floor, remote water level indicating or recording gauges must be installed at eye level above the operating floor.

     4. Each steam boiler must have one or more water gauge glasses attached to the water column or boiler by means of valved fittings. The lower fitting must be provided with a drain valve of the straightway type with an opening not less than 1/4-inch diameter to facilitate cleaning. The replacement of the gauge glass must be possible while the boiler is under pressure.

     5. Transparent materials other than glass may be used for the water gauge if the material has proved suitable for the pressure, temperature and corrosive conditions encountered in service.

     (Added to NAC by Div. of Industrial Relations by R101-02, eff. 12-15-2004)