Bulkhead Fittings
The basin walls of metal cooling towers are often modified to accept fittings for electric sump heaters, thermostats, water level indicators, water treatment, etc..
The easy way to do this is to use a water tight electrical bulkhead fitting from, say, Home Depot. Some cooling tower manufacturers even do this to accommodate accessories on their new cooling towers.
Operators should be aware that such a misapplication of materials intended for electrical service poses a serious potential for water damage when the fittings break and flood the area surrounding the cooling tower.
These fittings were simply not intended for immersion service which is the case for the portion of the fitting inside the cooling tower. Rapid deterioration occurs spurred on by water treatment chemicals and galvanic action of dissimilar metals. I have seen where fittings look perfectly fine outside the tower but fall out from the slightest touch due to the decay of the underwater collar inside the tower.
Every operator reading this should schedule immediate replacement of any such fittings found on their towers. Galvanized steel basins need galvanized steel replacements and stainless steel basins need stainless steel replacements.
The necessary parts aren't available from any supply house that I'm aware of and must be made by welding a half coupling or weld-o-let to a steel plate and installing this subassembly onto the tower. It is typically not a good idea to weld fittings to towers directly.
Give us a call if you have any doubts about the bulkhead fittings on your cooling tower.