When the plate-type coolers are opened up for inspection they should be checked properly for holes as they could leak later. Further, the joints should be checked for their sealing surfaces and pasting as well.
Ensure that the plate pack is tightened to specification and that the carrying and guide bars are lubricated. Check the pressure gauges at each end of the plate heat exchanger to make sure the pressure drop is within the expected limits.
For cleaning the Plate Type HE, fresh water flushing can be used to flush out the impurities till the water runs clear. If there is a need to open the plates of the heat exchanger for cleaning, ensure to open the plate pack according to the manufacturer’s instructions.
It’s preferable to clean the plates without taking them out of the frame. Avoid using wire brushes or metal pads as they may score the plates. The plates can be cleaned with fresh water however, avoid hitting the gaskets with the water directly, as the high pressure may loosen or dislodge them.
These types of coolers have a filter on the seawater side, which should be opened up regularly for the removal of debris, which apparently can cause the joints to leak and also reduce the effecting heat transfer area. If the coolers are to be put out of service for long periods then the seawater side should be drained completely, flushed with fresh water, and then dried to be used again.