continuous or intermittent, and 140 dB peak sound pressure, impulse or
impact, shall be maintained. The sound level meter shall conform as a
minimum to the Type 2 requirements cited in ANSI S1.4.
2.2
BOILER BREECHING
2.2.1
Round Breeching
Construct round breeching of black iron or steel in accordance with NFPA 211
for metal connectors for medium-heat appliances and shall be constructed
with welded beams and joints. Round breechings also may consist of
approved factory-built chimney sections for medium-heat appliances if the
sections are joined together with continuous welds, flanges, or couplings.
Provided suitable cleanouts that will permit cleaning the entire breeching
without dismantling.
2.2.2
Rectangular Breeching
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NOTE: Specifier should check structural steelwork
section of the project specification, if used, as
well as notes on structural drawings to ensure
against conflict of requirements.
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Structural materials shall comply with the applicable sections of AISC 335.
Shop connections may be welded or bolted as required for joining breeching
to equipment. Supply hot dipped galvanized bolts and lock washers for
bolted connections. Bolts shall be not less than 10 mm 3/8 inch in
diameter, and spaced not more than 76 mm 3 inchesapart. Furnish bolted
joints with 3.20 mm 1/8 inch thick non-asbestos gaskets. Breeching [plate]
shall be not less than [12 MS gage steel] [4.80 mm3/16 inch thick]. Welds
shall conform to AWS D1.1/D1.1M. Breeching system shall provide for
maximum expansion and contraction. Expansion joints shall be of the guided
flexible crease type with flexible element of not less than 1.60 mm 0.0625
inch thick stainless steel. Provide access doors and cast iron or
reinforced steel plate with non-asbestos gaskets 3.20 mm 1/8 inch thick and
positive closing latches of sufficient number to ensure a gas-tight seal.
Thoroughly clean breeching of rust and scale after fabrication by
commercial sand blasting.
2.2.3
Breeching Hangers
Design breeching hangers to carry not less than five times the breeching
weight. Hangers for round breeching shall be of the band type with hanger
rods. Provide steel tappeze type hangers for rectangular breeching with
angle support member and hanger rods.
2.2.4
Cleanout Doors
Secure cleanout doors to the ends and sides of the breeching where
indicated or where required to effectively clean the breeching. Construct
cleanout doors of a gage steel not less than that of the breeching and
secure to a 32 by 32 inch 1 1/4 by 1 1/4 inch angle frame not less than
3.20 mm 1/8 inch in thickness with mounting bolts welded to the angle frame
and spaced not over 152 mm 6 inches on center; provide 1.60 mm 1/16 inch
thick long fiber non-asbestos gasket between cleanout doors and frames.
Doors shall be squared and shall be full height of diameter or side of
breeching up to a size of 610 mm by 610 mm 24 inches by 24 inches maximum,
SECTION 15516N
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