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The precautions for disassembling and inspecting a plate heat exchanger are as follows: 01 Before disassembling the plate heat exchanger, the compression length of the plate pack should be measured and recorded (this dimension should be used when reassembling it). 02 If the gasket gets stuck in the groove between the two plates, it is necessary to carefully separate them using a screwdriver. The screwdriver should be inserted at the area where it is easier to separate the components, and then used to separate them along the edges; care must be taken not to damage either the heat exchanger plates or the gasket. 03 When replacing the new gasket, it is necessary to use acetone or other similar organic solvents to clean the grooves of the gasket. Then use a brush to apply the synthetic resin adhesive evenly in the grooves. 04 Check the heat exchanger plates for any perforations; this is usually done using a 5x magnifying glass, and sometimes light or kerosene penetration tests can also be used to inspect each plate individually. 05 If debris is found accumulated in the short pipes and passages at the media inlet and outlet, it indicates that the filter has failed and should be cleaned promptly. 06 There are three methods for cleaning the plates: the backflushing method (cleaning without disassembling), the manual cleaning method (cleaning by disassembling), and the chemical cleaning method (cleaning without disassembling). Manual cleaning method: When the scale thickness on the heat exchange plates is very thin and insoluble in water, the plates can be disassembled and each one can be cleaned by spraying with pressurized water (0.1–0.2 MPa) or low-pressure steam containing water. For deposits that are difficult to clean with water, soft fiber brushes or bristle brushes can be used for cleaning. Chemical cleaning method: On the surface of heat exchange plates, especially in the areas where the fluid flows and where deposits form, there are hard residues such as oxides or carbides. It is difficult to remove these residues using manual cleaning methods; therefore, different chemical solvents can be used for cleaning, depending on the material of the heat exchange plates. 07 When scarring occurs on the heat exchange plates, it is absolutely forbidden to use wire brushes or bristled brushes for cleaning, especially on stainless steel plates, to prevent accelerated corrosion of the plates. If there are stains or rust on the plate, they can be removed using cleaning powder. 08 The water used for cleaning must be free of salts, sulfur, and other substances. 09 After the heat exchange plates have been cleaned chemically, they must be rinsed thoroughly with clean water, then wiped dry with fine gauze, and stored in a clean place for later use. 10 When removing titanium plates, it is strictly prohibited to expose them to open flames to prevent oxidation. 11 Check the sealing gaskets for defects such as aging, deterioration, or cracks; do not use hard objects to scratch their surface. 12 Solid particles such as sand and iron slag must not accumulate on the surface of the sealing gasket and the heat exchange plates (within the grooves). 13 Check whether the heat exchange plates are locally deformed; those exceeding the allowable values should be trimmed or replaced.