Louisiana Administrative Code › Title 55 - PUBLIC SAFETY › Part V - Fire Protection › Chapter 50 - Boiler Construction, Maintenance, Inspection and General Use › Subchapter C - Existing Installations- Power Boilers › Section V-5027 - Water Level Indicators

Current through Register Vol. 50, No. 6, June 20, 2024
A. Each
				  boiler, except forced-flow steam generators with no fixed steam and waterline,
				  and high-temperature water boiler of the forced circulation type that have no
				  steam and waterline, shall have at least one water gage glass. Boilers operated
				  at pressures over 400 psig shall be provided with two water gage glasses which
				  may be connected to a single water column or connected directly to the
				  drum.
B. Two independent remote
				  level indicators may be provided instead of one of the two required gage
				  glasses for boiler drum water level indication in the case of power boilers
				  with all drum safety valves set at or above 400 psig. When both remote level
				  indicators are in reliable operation, the remaining gage glass may be shut off,
				  but shall be maintained in serviceable condition.
C. When the direct reading of gage glass
				  water level is not readily visible to the operator in his/her working area, two
				  dependable indirect indications shall be provided, either by transmission of
				  the gage glass image or by remote level indicators.
D. The lowest visible part of the water gage
				  glass shall be at least two inches above the lowest permissible water level, at
				  which level there will be no danger of overheating any part of the boiler when
				  in operation at that level. When remote level indication is provided for the
				  operator in lieu of the gage glass, the same minimum level reference shall be
				  clearly marked.
E. Connections from
				  the boiler to the remote level indicator shall be at least 3/4 inch pipe size
				  to and including the isolation valve and from there to the remote level
				  indicator at least 1/2 inch O.D. tubing. These connections shall be completely
				  independent of other connections for any function other than water level
				  indication. For pressures of 400 psig or over, lower connections to drums shall
				  be provided with shields, sleeves, or other suitable means to reduce
				  temperature differentials in the shells or heads.
F. Boilers of the horizontal fire tube types
				  shall be so set that when the water is at the lowest reading in the water gage
				  glass there shall be at least 3 inches of water over the highest point of the
				  tubes, flues, or crown sheets.
G.
				  Boilers of locomotives shall have at least one water glass provided with top
				  and bottom shutoff cocks and lamp, and two gage cocks for boilers 36 inches in
				  diameter and under, and three gage cocks for boilers over 36 inches in
				  diameter.
H. The lowest gage cock
				  and the lowest reading of water glass shall not be less that 2 inches above the
				  highest point of crown sheet on boilers 36 inches in diameter and under, nor
				  less than 3 inches for boilers over 36 inches in diameter. These are minimum
				  dimensions, and on larger locomotives and those operating on steep grades, the
				  height should be increased, if necessary, to compensate for change of water
				  level on descending grades.
I. The
				  bottom mounting for water glass and for water column if used must extend not
				  less than 1 1/2 inches inside the boiler and beyond any obstacle immediately
				  above it, and the passage therein must be straight and horizontal.
J. Tubular water glasses must be equipped
				  with a protecting shield.
K. All
				  connections on the gage glass shall be not less than 1/2 inch pipe size. Each
				  water gage glass shall be fitted with a drain cock or valve having an
				  unrestricted drain opening of not less than 1/4 inch diameter to facilitate
				  cleaning. When the boiler operating pressure exceeds 100 psig the glass shall
				  be furnished with a connection to install a valved drain to the ash pit or
				  other safe discharge point.
L. Each
				  water gage glass shall be equipped with a top and bottom shutoff valve of such
				  through-flow construction as to prevent stoppage by deposits of sediments. If
				  the lowest valve is more than 7 feet above the floor or platform from which it
				  is operated, the operating mechanism shall indicate by its position whether the
				  valve is open or closed. The pressure-temperature rating shall be at least
				  equal to that if the lowest set pressure of any safety valve on the boiler drum
				  and the corresponding saturated-steam temperature.
M. Straight-run globe valves shall not be
				  used on such connections.
N.
				  Automatic shutoff valves, if permitted to be used, shall conform to the
				  requirements of Section I of the ASME Code.
AUTHORITY NOTE:
					 Promulgated in accordance with
					 R.S.
					 23:531 and
					 R.S.
					 51:1424.