Water-Cooled Heat Exchangers; Fluid Piping - Quincy QSF Series Instruction Manual

Water-cooled Heat Exchangers

The majority of water-cooled heat exchanger problems are due to underestimating the importance of
water treatment and heat exchanger maintenance. Efficient, long service life can be obtained only when
clean, soft and/or treated water is used and the exchanger tubes are cleaned on a regular basis.
In many instances, the cooling water supply for the heat exchanger will contain impurities dissolved in
solution and/or in suspension. These substances can cause scale formation, corrosion and fouling
(plugging) of any water-cooled heat exchanger equipment. Disregarding the possibility that one or
more of these conditions exist may result in increased maintenance and operation expense, reduced
equipment life and emergency shutdown. In some cases, what is normally considered plain drinking
water can contain corrosive substances that will impact the heat exchanger's life.
It is strongly recommended that a reputable, local water treatment concern be engaged to establish the
corrosion, scale forming and fouling tendency of the cooling water and take steps necessary to remedy
the situation if a problem does exist. The need for water treatment may only involve filtration (screening)
to remove debris, sand and/or silt in the cooling water supply. However, chemical treatment methods
may be necessary, in certain instances, to inhibit corrosion and/or remove suspended solids, to alter the
water's tendency to form scale deposits, or prevent growth of micro-organisms. The normal
maintenance program for the unit should include periodic cleaning of the tube side (water side) of the
heat exchanger to remove deposits that enhance fouling and corrosion.
If overheating or fluid leakage to the water side develops, remove the end caps and inspect for scale
and corrosion. If present, this is usually the source of trouble. In the case of a closed system, the entire
system, cooling tower, cooler inlet and outlet lines should be inspected and cleaned as necessary.
Except for obvious mechanical failures, the solution to most heat exchanger problems lies at the point of
use. It is the users responsibility to provide the proper quality of water and to keep the exchange clean.
No heat exchanger made will resist plugging and corrosion if the basic rules of clean water and regular
maintenance are disregarded.
FAILURES ON HEAT EXCHANGERS CAUSED BY PLUGGING OR CORROSION ARE
NOT COVERED UNDER WARRANTY.

Fluid Piping

Fluid piping on QSF units incorporates a machine-rolled flare tube and a "SEAL-LOK" fitting. Proper
assembly methods for "SEAL-LOK" fittings are listed below.
! WARNING !
Quincy Compressor – QSF Series
Section VI– Service Adjustments
37