Cooling Tower Isolation

Four temperatures and two pressure drops tell you almost everything. Inlet and outlet on each side give the approach, and a tower side pressure drop that rises while flow holds steady points to deposit in the channels. Log them weekly from day one, because a clean baseline is what turns later readings into a decision rather than a guess.

In almost every case, since tower basins collect leaves, scale flakes and debris that lodge at the plate ports. A strainer finer than the narrowest gap in the plate channel stops most of that before it arrives. Fit it with differential pressure gauges or a switch and clean it on reading, because a blocked strainer starves the exchanger just as surely as fouled plates.

The closed side needs a corrosion inhibitor and a sealed system even though it never sees tower water. Without them, oxygen entering through make-up and air vents produces corrosion products that settle on the plates from the clean side. Keep the loop topped up through a proper fill station and test the inhibitor on a schedule.

Circulating a cleaning solution through the tower side alone is common, and the closed loop can stay filled and isolated while it happens. Opening the frame is different, because loosening the pack releases both sides, so plan a full drain for a mechanical clean. Recheck the pack tightening dimension when it closes again, since the wrong length either leaks or crushes gaskets.

A tower running at low load in winter can deliver water cold enough to freeze in a stagnant plate channel, especially if a valve cuts the flow back. Keep a minimum flow through the tower side, or drain it when the system is down. Ice in a plate pack distorts plates and can split gaskets, and the damage often shows only at the next startup.