Section 12-222.1-7 - Power boiler appurtenances(a) Water level indicators. The following shall apply to all water level indicators: (1) Each boiler shall have at least one water gage glass, except forced-flow steam generators with no fixed steam and waterline and high-temperature water boilers of the forced circulation type that have no steam and waterline;(2) The lowest visible water level in a gage glass shall be at least two inches above the lowest permissible water level as determined by the manufacturer;(3) Gage glasses shall be connected directly to the shell or drum of the boiler or to an intervening water column;(4) The lower edge of the steam connection between a water column, gage glass, or water level sending device in the boiler, shall not fall below the highest visible water level in the gage glass. In addition, there shall be no sag of offset in the piping that will permit accumulation of water;(5) The upper edge of the water connection between water column, gage glass, or water level sensing device in the boiler, shall not be above the lowest visible water level in the gage glass. In addition, no part of the pipe connection shall be above the point of connection at the water column;(6) Boilers having a maximum allowable working pressure of 400 psi or less shall always have at least one gage glass in service;(7) Boilers having maximum allowable working pressure greater than 400 psi shall always have two gage glasses in service: (A) When two gage glasses are required, both may connect to a single water column;(B) Instead of one of the two required gage glasses, two independent remote water level indicators (two discrete systems that continuously measure, transmit, and display water level) may be provided. In addition, minimum water levels shall be clearly marked;(C) When both remote level indicators are in reliable operation, the remaining gage glass may be shut off, but shall be maintained in serviceable condition; and(D) When the water level in at least one gage glass is not readily visible to the operator in the area where control actions are initiated, either a fiber optic cable (with no electrical modification of the optical signal) or mirrors shall be provided to transfer the optical image of the water level to the control area. Alternatively, any combination of two of the following shall be provided:(i) An independent remote water level indicator; and(ii) An independent continuous transmission and display of an image of the water level in a gage glass. The display of a remote water level indicator shall have a clearly marked minimum water level reference at least two (2) inches above the lowest permissible water level, as determined by the manufacturer;(8) Gage glass assemblies with multiple sections, whether of tubular or other construction, shall: (A) Ensure a one-foot overlap of all adjoining sections so the water level is visible; or(B) Ported or reflex gages using refractive light to aid determination of water level may omit the requirement of overlapping sections;(9) The gage glass cock connections shall not be less than one-half (1/2) of an inch NPS; (10) Each gage glass, externally mounted water level, or water level controlling device shall be fitted with a drain cock or valve having an unrestricted drain opening of not less than one-fourth (1/4) of an inch in diameter to facilitate cleaning; (11) No outlet connections, except for damper regulators, feedwater regulators, drains, steam gages, or apparatus of a form that does not permit the escape of an appreciable amount of steam or water therefrom, shall be placed in the pipes connecting a water column or gage glass to a boiler;(12) The water column shall be fitted with a drain cock or drain valve of at least three-fourths (3/4) of an inch nominal pipe size and shall be piped to a safe point of discharge;(13) Connections from the boiler to the water column shall be at least NPS 1;(14) Connections for gage glasses connected directly to the boiler or to an intervening water column shall be at least NPS one-half (1/2)(15) Connections from the boiler to a remote water level indicator shall be at least NPS three-fourths (3/4), including the isolation valve; and from there to the remote level indicator at least one-half (1/2) of an inch in CD tubing;(16) Water level connections shall be completely independent of other connections for any function other than water level indication;(17) The steam and water connections to a water column or a water gage glass shall be readily accessible for internal inspection and cleaning; and(18) Shutoff valves shall not be used in the pipe connections between a boiler and a water column, or between a boiler and the shutoff valves required for the gage glass, except: (A) Outside screw-and-yoke or lever-lifting-type gate valves or stopcocks with lever permanently fastened thereto and marked in line with their passage; and(B) Another through-flow construction that prevents stoppage by deposits of sediment, and to indicate by the position of the operating mechanisms whether they are in open or closed position. These valves or cocks shall be locked or sealed open. Where stopcocks are used, they shall be of a type with the plug held in place by a guard or gland.(b) Low-water fuel cutoffs and water feeding devices. The following shall apply to low-water fuel cutoffs and water feeding devices:(1) Each automatically fired, high pressure steam boiler, except miniature boilers, shall have at least two automatic low water fuel cut-off devices. When installed external to the boiler, each device shall be installed in individual chambers (water columns), which shall be attached to the boiler by separate pipe connections below the waterline. A common steam connection is permissible. Each cut-off device shall be installed to prevent startup and cut off the boiler fuel or energy supply automatically when the surface of the water falls to a level not lower than the lowest visible part of the gage glass. One control shall be set to function ahead of the other;(2) Functioning of the lower of the two controls shall cause safety shutdown and lockout. The manual reset may be incorporated in the lower cut-off 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 (3) minutes after the fuel has been cut off;(3) The fuel cut-off device may be inserted internally or attached externally to the boiler. An external cut-off device may be attached on piping connecting a water column to the boiler or combined with a water column;(4) Water column piping and connections shall be at least NPS 1 (DN 25). If the low-water fuel cutoff is connected to the boiler by pipe or fittings, no shutoff valves of any type shall be placed in such piping. The steam and water connections to a water column shall be readily accessible for internal inspection and cleaning. Some acceptable methods of meeting this requirement are by providing a cross-fitting with a back outlet at each right-angle turn to permit inspection and cleaning in both directions or by using pipe bends or fittings of a type that does not leave an internal shoulder or pocket in the pipe connection and with a radius of curvature that will permit the passage of a rotary cleaner. Fuel cut-off devices embodying a separate chamber shall have a vertical drainpipe and blowoff valve, not less than NPS 3/4, located at the lowest point of the chamber or water-equalizing pipe connections, so that the chamber and the equalizing pipe can be flushed and the device tested;(5) Each miniature boiler, except electric boilers of the electrode type, shall have at least one low water fuel cut-off device;(6) These devices shall be installed in such a manner that they cannot be rendered inoperative by the manipulation of any manual control or regulating apparatus;(7) In boilers with a fixed water line, the low-water fuel cutoff devices shall be tested regularly by lowering the water level sufficiently to shut off the fuel supply to the burner when the water level reaches the lowest safe level for operation. Boilers that do not have a fixed water line shall be equipped with a flow sensing device, thermal couple or expansion ring that is listed by a nationally recognized testing agency to prevent burner operation at a flow rate inadequate to protect the boiler unit against overheating;(8) Boilers with single drain electronic solenoid valve shall be fitted with a manual by-pass drain line to facilitate testing of the low water cutoff safety device; (9) The low-water cutoff shall be rated for a pressure and temperature equal to or greater than the MAWP and temperature of the boiler;(10) For high-temperature water boilers requiring forced flow circulation, an approved flow sensing device shall be installed on the outlet, as close to the boiler as possible;(11) When a low-water fuel cutoff and feedwater pump control is combined in a single device, an additional separate low-water fuel cutoff shall be installed. The additional control shall be wired in series electrically with the existing low-water fuel cutoff;(12) When a low-water fuel cutoff is housed in either the water column or a separate chamber it shall be provided with a blowdown pipe and valve not less than 3/4 inch NPS. The arrangement shall be such that when the water column is blown down, the water level in it will be lowered sufficiently to activate the lower-water fuel cutoff device; and(13) If a water feed device is utilized, it shall be constructed to prevent feedwater from entering the boiler through the water column or separate chamber of the low-water fuel cutoff.Haw. Code R. § 12-222.1-7
[Eff and comp 12/21/2019] (Auth: HRS § 397-4) (Imp: HRS § 397-4)