Mechanical Integrity 101 | Inspection of Cold Storage Bunkers

In the fresh fruit and vegetable industry in Central California, it is very common for facilities to use bunker-mounted air-cooling evaporators. A typical installation of a bunker-mounted evaporator can been seen in the schematic below:

Performing a mechanical integrity inspection of a bunker-mounted evaporator requires many of the same inspection protocols that any air-cooled evaporator requires. The inspector should look for unusual ice-build up, corrosion, vibration, etc., but because a bunker-mounted evaporator is supported from the ground, it is very important that the support structure for the evaporator is properly inspected. Recently, while performing an MI inspection of a bunker-mounted evaporator, it was determined that the evaporator was suspended above two of the four braces that were designed to carry the entire load of the coil. The picture below shows one of the two evaporator supports that was found suspended above the support.

This condition had existed since the original installation nearly a decade prior and if it continued to exist without being addressed could certainly have lead to early evaporator failure due to the excessive stresses experienced by the coil.