Specifications
Specification Value
Marley
/
Sigma F Series
Cooling Tower
/
Specifications: Base
17
7.0
Hot Water Distribution System:
7.1
The mechanical equipment support/
crossover pipe for each cell shall be
equipped with a flange for the attachment
of customer supply piping. Inlet and bolt
circle dimensions shall conform to 125#
flange specifications. The crossover pipe
shall deliver water through PVC perforat-
ed pipes to two open, stainless steel, hot
water basins at the fan deck elevation.
Water shall exit these basins to the fill by
gravity through metering orifice type poly-
propylene nozzles situated in the basin
floor. Nozzles shall be easily removable
and replaceable.
7.2
Water inlet system shall be self-
balancing, requiring no special valving
for flow regulation from side-to-side of
tower.
7.3
Water distribution system design shall
allow water flow reductions down to
50% of design flow without modifica-
tions or adjustments.
8.0
Casing:
8.1
The endwalls of the tower, as well
as the sidewalls above the air inlet
elevation to the top of the distribution
basin, shall be cased with 12 oz/sq
ft horizontally corrugated FRP panels
attached to tower columns with stain-
less steel self-tapping fasteners and
self-sealing washers. Panels shall be
lapped to shed water inward to the
tower. Vertical joints shall be lapped
and sealed watertight. Casing ends at
tower corners shall be covered with
pultruded FRP angles.
8.2
In the water-washed endwall fill areas,
inner casings of 16 gauge 304 stain-
less steel shall also be provided.
■
Gravity-flow distribution basins are a feature of crossflow type
towers. These basins are out where they can be easily inspect-
ed—even cleaned—while the tower is in operation. Spray sys-
tems of counterflow towers, being sandwiched between the top
of the fill and the drift eliminators, are extremely awkward to
access and maintain, and require the system to be shut down for
cleaning.
The Sigma F Series is designed such that the supply piping to
the tower will not appear outside the tower. Not only does this
enhance the tower's architectural appearance, but it also aids the
self-balancing aspect of the Sigma F Series water distribution
system.
This feature of the Sigma F Series tower allows you to vary the
water circulation rate as an added means of controlling tower per-
formance capacity during reduced-load or off-season operation.
■
8 oz casing panels are also available at reduced cost, but the stur-
dier 12 oz panels are strongly recommended.
Also, if fire-retardant casing is preferred, it would be appropriate
to add the following sentence to the end of paragraph 8.1 at left:
“Casing panels shall have a flame spread rating of 25 or less."
Heavy duty architectural casing panels are also available, as
described on page 23.
Architectural treatment can also be enhanced by extending the
casing up to the top of the fan deck guardrail. This is described on
page 23.
