Expansion joints shall be preformed with integrally molded corners,
suitable for mounting against a 150 mm 6 inch flange. [Provide carbon
steel backup bars with slotted holes, bolts, and nuts.]
2.8.3
Breeching Hangers
Design breeching hangers to carry not less than 5 times the breeching
weight. Hangers for round breeching shall be of the band type, with hanger
rods. Hangers for rectangular breeching shall be of the trapeze type, with
angle support member and hanger rods. Make all hangers of steel.
2.8.4
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 mm 1 1/4 by 1 1/4 inch angle frame and spaced not over
152 mm 6 inches on center; provide 1.60 mm 1/16 inch thick 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 24 inches maximum, except for cleanout doors less than 305 mm
12 inches in height shall be rectangular and shall be 305 mm 12 inches in
length. Plug type cleanouts are not acceptable. Provide additional
cleanout doors where needed.
2.9
BOILER STACKS
Provide [One] [_____] [refractory-lined], [dual wall insulated], steel
stack(s), [each] [_____] mm inches in diameter inside [refractory] by
[_____] meter feet overall length, and install where indicated.
2.9.1
Construction
[The] [Each] stack may be factory or field assembled. [The] [Each] stack
shall be [prefabricated double or triple walled] [fabricated] of 6.40 mm
1/4 inch structural steel plates in accordance with ASTM A 283/A 283M.
Stack sections shall be of welded construction and fabricated in sections
not greater than 6 meters 20 feet nor less than 1.50 meters 5 feet in
length. Longitudinal seams shall have continuous butt welded joints. The
section or horizontal joints of [refractory lined] stacks shall be flanged
with angles welded to the shell, and sections bolted together. Angles
shall be not less than 50 mm by 50 mm by 6.40 mm 2 inches by 2 inches by
1/4 inch. [The refractory joint shall be "buttered" with a high
temperature air setting bonding refractory before each section is
assembled.] Stacks shall be set on a 13 mm 1/2 inch thick steel base plate
having a diameter 50 mm 2 inches larger than the outside diameter of the
base angle. Base angles and anchor shall be a minimum of 10 mm 3/8 inch
thick and 13 mm 1/2 inch diameter. A reinforced concrete foundation shall
be provided. Concrete for foundation and reinforcing shall be as detailed
on drawings and as specified under the concrete section of this
specification. Provide stacks with steel guide shoes and bearing plates on
all four sides at the roof level. Guides and bearing plates shall be
structural shapes not less than 6.40 mm 1/4 inch thick. Guides shall be
not less than 305 mm 12 inches long and shall be welded to the stacks.
Bearing member shall be fastened with steel stud anchors welded to the
bearing member. Provided a clearance of 3.20 mm 1/8 inch between guide and
bearing member for stack diameter expansion after stacks are in normal
operation. Provide flashing and counter-flashing around [the] [each] stack
as detailed on drawings.
SECTION 15517N
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