2.14.10
All Welded Blowdown Tank
Provide in accordance with the NBBPVI NB-27 (supplemental to the National
Board Inspection Code) latest edition published by the National Board of
Boiler and Pressure Vessel Inspectors, Columbus, Ohio.
2.14.10.1
Construction
**************************************************************************
NOTE: The volume of the blowdown tank shall be
calculated to be twice the volume of water removed
from one boiler when the normal water level is
reduced not less than 100 mm 4 inches.
**************************************************************************
Construct equipment and accessories in accordance with requirements of ASME
BPVC SEC VIII D1 for a working pressure of at least the maximum allowable
working pressure of the boiler but in no case shall plate thickness be less
than 10 mm 3/8 inch. Provide corrosion allowance of [2.54] [_____] mm
[0.1] [_____] inch. Tank dimensions shall be [_____] meters feet [_____] mm
inches o.d. by [_____] meters feet [_____] mm inches long over the heads
(overall). Provide tank with wear plate not less than 10 mm 3/8 inch thick
and [279 by 381 mm] [457 by 508 mm] [11 by 15 inch] [18 by 20 inch] manhole.
a.
Provide the following tank connections:
(1) Blowdown inlet for bottom blowdown:
[20] [25] mm [3/4] [one]
inch;
(2)
Tangential blowdown inlet:
[_____] mm inch;
(3)
Steam vent, flanged:
[_____] mm inch;
(4) Discharge water outlet, flanged: [_____] mm inch with
internal water seal and 20 mm3/4 inch siphon breaker;
(5)
Drain:
50 mm 2 inch;
(6)
Thermometer connection:
20 mm 3/4 inch;
(7)
Pressure gage connection:
6 mm 1/4 inch;
(8) Cold water inlet: [_____] mm inch with temperature
regulating valve and backflow preventer; and
(9)
Two gage glass connections:
15 mm 1/2 inch.
b.
Angle Supports and Coating: Provide tank with steel angle support
legs extending [_____] meters feet below bottom of tank. Coat
tank with one coat of manufacturer's standard high temperature
primer.
2.14.10.2
Accessories
a.
Gage Glass:
300 mm 12 inch reflex type with shutoff valves and
guard.
b.
Thermometer:
Bi-metal dial type with separable socket, 125 mm 5
SECTION 15501N
Page 136
Previous Page
