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-5032 - Blow Off Piping

Current through Register Vol. 50, No. 6, June 20, 2024
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.
AUTHORITY NOTE:
					 Promulgated in accordance with
					 R.S.
					 23:531 and
					 R.S.
					 51:1424.