Hawaii Administrative Rules › Title 12 - DEPARTMENT OF LABOR AND INDUSTRIAL RELATIONS › Subtitle 8 - HAWAII OCCUPATIONAL SAFETY AND HEALTH DIVISION › Part 10 - BOILER AND PRESSURE VESSEL › Chapter 222.1 - POWER BOILERS › Section 12-222.1-7 - Power boiler appurtenances

Current through June,
				  2024
(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.