Some gasketed plate heat exchanger designs allow the distance between pressure plates to be adjusted to reduce the space and compensate for the gradual loss of elasticity in the gaskets. To find out if your heat exchanger has this feature, look on the data plate for an “A-max” and “A-min” dimension.

If it does, and if a gasketed plate heat exchanger develops a small leak, try tightening the tie rods approximately 10 percent of the distance between the “A-max” and “A-min” dimensions, then rechecking for the leak. If it stops the leak, keep track of the date and amount of tightening as a means to predict when gasket replacement will be needed, and plan your outage accordingly.

When performing this adjustment, remember these tips:
  • Never tighten beyond the “A-min” dimension, as this will risk destroying the plates.
  • Never tighten based on torque. The measurement that counts is the A-dimension.
  • The A-dimension should always be the same around the perimeter of the plates.
  • Keep a small stock of emergency spare parts.
At any given time, it is smart to keep an emergency stock of 3 percent plates with gaskets, and 5 percent gaskets. The emergency gasket stock should be renewed every two years or when the planned maintenance is done, whichever comes first. The reason for the emergency stock is the risk of damage from system operational failures such as pressure shock from the sudden open or close of an on/off valve, or pressure shock from a starting pump. A gasketed plate heat exchangers can be easily repaired, and the job is much easier if the parts are readily available.

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