Case Studies

Flooding from Failure of Fitting on Airconditioning Unit

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Outline of the project

A contractor was carrying out maintenance to the heating and ventilation fan coil units in an office building. The work involved replacement of the fan motor and the water supply was not switched off. When the unit was started up again a joint in the cold water supply to the unit failed and the office equipment below was flooded.

Cadogans was asked to prepare a report and give an opinion on the cause of the failure.

Work done by Cadogans

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Cadogans' engineer inspected the failed compression fitting and took measurements. It appeared that the fitting had not been made properly when the system was installed some considerable time before.

In order to confirm this, and to determine the load that would be required to pull the pipe out of an incorrectly made fitting, tests were carried out in Cadogans' offices. Several fittings were incorrectly made and were tested by applying weights to the pipe (see photograph above).

It was concluded that the immediate cause of the leak was likely to have been a mechanical load placed on the pipe by the fitter when reaching the electrical switch above the pipes.

Cadogans also checked the manufacturer's recommended procedures for the motor replacement to confirm whether the water supply should have been isolated.

Engineering Discipline

People