standard hydrostatic test for leak(plug and tub) on air cooled heat exchangers
I don't know if it is a standard procedure but here is how I used to do it. You need to close off all of the openings on the exchanger leavings a valved one at the high point of the exchanger for an air vent and one other for filling the exchanger with clean fresh water. Once the unit is filled with water and all air expelled, you attach a pump to the fill point and a pressure gage at the high point. Pressure the unit up to desired test pressure which is typically 1.5 times the design pressure or maximum allowable working pressure. Hold that pressure for approximately an hour during which time all of the tubes, plugs, joints and welds should be monitored for leaks. If any leaks are found they need to be fixed and the procedure repeated until there are no leaks.
