La. Admin. Code tit. 55 § V-5027

Current through Register Vol. 50, No. 11, November 20, 2024

Section V-5027 - Water Level Indicators

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.

La. Admin. Code tit. 55, § V-5027

Promulgated by the Department of Public Safety, Office of the State Fire Marshal, LR 33:1358 (July 2007).

AUTHORITY NOTE: Promulgated in accordance with R.S. 23:531 and R.S. 51:1424.