External leaks from old seal gaskets and deposits in the heat exchanger, such as scaling, are the two most common causes of reduced heat exchanger efficiency, This reduces heat transfer efficiency and eventually clogs the channels. To solve these problems, the heat exchanger needs to be refurbished and repaired.

（1）Checking the heat exchanger

Firstly, checking the heat exchanger plates for severe corrosion, erosion and deformation. This will determine if the plate should be refurbished or replaced.

（2）Gasket removal

We use liquid nitrogen to remove the gaskets, a method that completely removes the spacers while leaving the grooves intact and preventing damage to the plates. Using a propane torch or a rotating wire brush can severely damage the plates.

（3）Water cleaning

The heat exchanger plates are initially washed with water to remove residues.

（4）Chemical cleaning

Plates are immersed in a specially formulated chemical bath, its concentration and temperature are carefully adjusted to gently remove deposits.

（5）Crack and deformity detection

Each plate is sprayed with dye and needs to be carefully inspected under UV light in order to spot even the smallest defects.

（6）Regasketing

（7）Oven-cured gasketing

Plates are then placed in a curing station and baked in an oven under compression for 3-5 hours.

（8）Pressure testing

When reassembling the heat exchanger, a full hydrostatic pressure test is required to ensure that there are no leaks.