or two sizes smaller.
**************************************************************************
The supply to the [elevated tank] [standpipe] [reservoir] shall be
controlled by a [_____] mm inch altitude valve, automatic in operation and
accurately set to prevent overflow of the [elevated tank] [standpipe]
[reservoir]. The valve shall have flanged ends and a heavy cast iron body,
shall be bronze fitted with renewable cups and seats, and shall be designed
without metal-to-metal seats. The valve shall be cushioned when opening
and closing to prevent water hammer or shock. Valves shall be provided
with a travel indicator.
2.1.6
Pressure Gauge
Pressure gauge of the direct-reading type, equipped with a shutoff cock,
shall be provided, in the valve chamber, on the tank side and on the
discharge side of the check or altitude valve. Gauges shall have 150 mm 6
inch dials, shall be stem mounted, and shall conform to ASME B40.100.
Accuracy of gauges shall be Grade A or better. Gauges shall be calibrated
in kilopascals and psi psi in not more than 10 kilopascals and psi 2 psi
increments from 0 to 350 kilopascals and 0 to 50 psi 0 to 50 psi in excess
of the normal operating pressure at the tank.
2.2
ASSEMBLIES
2.2.1
Tank Accessories
Section 7 of AWWA D100 or Section 5 of AWWA D103 and as specified.
Additional requirements for accessories are as follows:
2.2.1.1
Manholes and Pipe Connections
Section 7 of AWWA D100 and Section 5 of AWWA D103 represent the minimum
requirements. Number, type, location, and size of manholes and pipe
connections shall be as shown on the drawings. Inlet pipe connections to
extend [_____] mm inches above tank bottom and shall be provided with
deflectors as shown on the drawings. Outlet pipe connections to extend
[_____] mm inches above tank bottom and shall be provided with vortex
breakers as shown on the drawings.
2.2.1.2
Overflow
The overflow for the tank shall consist of an overflow weir and [stub
overflow] [outside drop pipe, adequately supported and] capable of
discharging at a rate of [_____] L/second gpm with [_____] mm inches of
head [, without the water level exceeding [_____]]. [The top of the weir
shall be [_____] mm inches below [_____].] [The weir shall be located as
indicated.] The [stub overflow shall be steel, ASTM A 53/A 53M or equal,
and shall be fitted with a screen] [overflow pipe shall be steel, ASTM A
53/A 53M or equal, and shall terminate 300 to 600 mm 1 to 2 feet above
grade and shall be fitted with a flapper valve or screen to prevent ingress
of animals and insects].
2.2.1.3
Vent
Vent shall be welded to the cover plate of the center manhole on the roof.
Vent will be tank manufacturer's standard type mushroom vent with aluminum
bird screen. The free area of the vent shall be sized 50 percent in excess
of the [_____] L/second gpm pump-in rate and [_____] L/second gpm pump-out
SECTION 13209
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