through it will result in overheating and seizure of the
This type of maintenance is normally performed
pump. Included in the corrective maintenance of the
by the ships engineering department; you should
circulating pump are repairing any leaks, replacing the
provide assistance if it is needed. Figure 2-19 shows
mechanical seal, and cleaning the internal parts.
a distilled-water circulating pump.
Figure 2-19.Distilled-water circulating pump.
Demineralizes are used to maintain the secondary
cooling systems water purity in an ultrapure state. By
maintaining the coolant at a high degree of purity,
corrosion and scale formation is minimized on the
Corrosion or scale on high-heat-density compo-
nents, such as waveguide dummy loads and klystrons,
results in the formation of a thermal barrier. The ther-
mal barrier reduces the effectiveness of heat transfer
at normal operating temperatures, which, in turn,
leads to premature failure of the components.
The demineralizer is connected between the sec-
ondary cooling system supply and return lines to cir-
culate water through it. The demineralizer is sized so
that 5 percent of the cooling system volume passes
through the demineralizer every hour. The coolant is
purified by organic compound adsorption (if re-
quired), oxygen removal, ion exchange processes, and
Figure 2-20 shows a typical three-cartridge demin-
eralizer. Some demineralizers use only two cartridges,
with one of the cartridges being a combination car-
tridge that provides organic compound adsorption, if
it is required.