except that 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.
2.2.5
Stacks
Stacks shall be constructed of not less than [12] [10] MS gage steel,
welded construction, and of proper size to adequately serve the respective
boiler. Stacks shall project above the boiler house roof not less than
that indicated and shall be supported by a substantial steel framework.
Provide structural steel framework at boiler room roof around each stack
and attached to roof joints to brace stack against swaying and to support
new roof curb and stub stack. Construct stacks as indicated to include
automatic damper access door, gas sampling connection, smoke density
indicator, temperature sensing connection, and other features shown or
required. When rain can fall into contact with internal boiler parts,
provide stub stacks with rain caps or hoods. Provide stacks with the
following:
a.
Provide curb openings in roof and properly flash and counterblock
to roofing. Furnish and install flashing hoods around stacks and
over roof curbs.
b.
Provide a bellows type flexible [fabric] [_____] type expansion
joint approximately 152 mm 6 inches wide in the stacks at the
location shown. Joint system shall consist of 4.80 mm 3/16 inch
steel plate welded to inside of bottom section of stack. Top
section of stack shall be free to move up and down outside the
plate. Weld steel reinforcing angles around both top and bottom
sections of stack. Fit and weld to the angles an expansion angle
type bellows of 12 gage steel.
c.
Clean stacks of dirt, rust, oil
and grease by wire brushing and
solvent degreasing and give one
shop coat of heat-resisting
aluminum paint conforming to FS
TT-P-28 on the inside and outside.
The coat of paint shall have a
minimum dry film thickness of one
mil.
2.3
BLOWDOWN EQUIPMENT
Furnish the [boiler] [plant] with all equipment, tanks, and controls
necessary for bottom [and continuous] blowdown of the boilers. The
equipment for bottom blowdown systems shall include a [blowdown tank] [and
sample cooler]. [Continuous blowdown systems shall be of the packaged,
proportional type consisting essentially of a heat exchanger, flow control
valve, surge tank, [and] sample cooler, [and blowdown control console with
test sink].] Install and pipe blowdown equipment as indicated, and conform
to recommendations of the NBBPVI NB-27, Recommended Rules for National
Board Boiler Blowoff Equipment.
2.3.1
Bottom Blowdown Tank
**************************************************************************
NOTE: Cathodic protection or magnesium anodes only
required when steel tank is buried.
**************************************************************************
Blowdown tank shall be fabricated of welded steel plate in accordance with
ASME BPVC SEC VIII. Tank shall be a vertical cylindrical tank designed for
SECTION 15516N
Page 17
Previous Page
