SPX Cooling Technologies Marley Sigma Steel - Manual (Page 13)

Specifications Specification Value
Marley / Sigma Steel Cooling Tower / Specifications: Base
13
2.0 Thermal Performance:
2.1 The tower shall be capable of cooling
_____ GPM of water from ____ °F to
_____ °F at a design entering air wet-
bulb temperature of _____ °F. The cool-
ing tower manufacturer shall guarantee
that the tower supplied will meet
the specified performance conditions
when the tower is installed according
to plans.
2.2 The purchaser will arrange for an
on-site thermal performance test, to
be conducted in the presence of the
manufacturer and owner, and under
the supervision of a qualified, disinter-
ested third party in accordance with
CTI (Cooling Technology Institute) ATC-
105 standards during the first full year
of operation. If the tower fails to per-
form within the limits of test tolerance,
then the cooling tower manufacturer
will install additional cells and/or make
such corrections as are agreeable to
the owner and shall pay for the cost of
a retest. If the tower still fails to per-
form as specified, then the manufac-
turer shall make such reimbursements
as are appropriate and agreeable to the
owner to compensate for the perfor-
mance deficiency.
■ Your reason for purchasing a cooling tower is to obtain a continuing
flow of cooled water as defined in the first paragraph at left. If the
tower that you purchase is incapable of performing as specified, then
you will not have received full value for your money.
Bear in mind that the size—and cost—of a cooling tower varies directly
with its true thermal capability. This paragraph is intended to protect
you against either intentional or inadvertent under sizing of the tower
by the manufacturer. Judging the level of performance of a cooling
tower on critical processes is never easy, and the potential risk of a
non-performing cooling tower usually causes the requirement for a
mandatory acceptance test to be very desirable.
Your contract with the successful bidder should establish the accept-
able remedies for missed performance, which might include:
• The addition of one or more cells of tower, as necessary, to bring the
cooling tower to the specified level of performance. This is usually
limited to the scope of work as defined in the specs, which means that
you (the owner) will have to pay for the additional basin, wiring, start-
ers, piping, etc.
• The reimbursement of a portion of the total contract price equal to the
percentage deficiency in performance.
Under no circumstances should you allow the manufacturer to re-pitch
the fans to increase motor brake horsepower above that shown in the
proposal. That creates additional operating costs that will continue for
the life of the tower—and imposes no penalty on the manufacturer.
Typical cooling tower performance curve.
55 °
50 ° 55 ° 60 ° 65 ° 70 ° 75 ° 80 °
5 °F RANGE
10 °F RANGE
15 °F RANGE
60 °
65 °
70 °
75 °
COLD WATER TEMP. (
°F)
WET BULB TEMP. ( °F)
80 °
85 °
90 °
95 °