La. Admin. Code tit. 55 § V-5032

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

Section V-5032 - Blow Off Piping

A. A blow off as required herein is defined as a pipe connection provided with valves located in the external piping through which the water in the boiler may be blown out under pressure, excepting drains such as are used on water columns, gage glasses, or piping to feed water regulators, etc., used for the purpose of determining the operating conditions of such equipment. Piping connections used primarily for continuous operation, such as deconcentrators or continuous blow down systems, are not classed as blow offs but the pipe connections and all fittings up to and including the first shutoff valve shall be equal at least to the pressure requirements for the lowest set pressure of any safety valve on the boiler drum and with the corresponding saturated-steam temperature.

B. A surface blow off shall not exceed 2 1/2 inch pipe size, and the internal pipe and the terminal connection for the external pipe, when used, shall form a continuous passage, but with clearance between their ends and arranged so that the removal of either will not disturb the other. A properly designed steel bushing, similar to or the equivalent of those shown in Fig. PG-59.1 of Section I of the ASME Code or a flanged connection shall be used.

C. Each boiler except forced-flow steam generators with no fixed steam and waterline and high-temperature water boilers shall have a bottom blow off outlet in direct connection with the lowest water space practicable for external piping conforming to PG-58.3.6 of Section I of the ASME Code.

D. All water walls and water screens which do not drain back into the boiler and all integral economizers, shall be equipped with outlet connections for a blow off or drain line and conform to the requirements of PG-58.3.6 or PG-58.3.7 of the ASME Code.

E. Except as permitted for miniature boilers, the minimum size of piping and fittings shall be 1 inch, and the maximum size shall be 2-1/2 inches, except that for boilers with 100 sq. ft. of heating surface or less, the minimum size of pipe and fittings may be 3/4 inch.

F. Condensate return connections of the same size or larger than the size herein specified may be used, and the blow off may be connected to them. In such case, the blow off shall be so located that the connection may be completely drained.

G. A bottom blow off pipe when exposed to direct furnace heat shall be protected by firebrick or other heat resisting material which is so arranged that the pipe may be inspected.

H. An opening in the boiler setting for a blow off pipe shall be arranged to provide free expansion and contraction.

La. Admin. Code tit. 55, § V-5032

Promulgated by the Department of Public Safety, Office of the State Fire Marshal, LR 33:1360 (July 2007).

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