What precautions should be taken when disassembling a plate-and-frame heat exchanger for cleaning?

Before disassembly, all energy sources—including water, steam, and electricity—must be fully isolated. Pressure must be relieved from both sides of the unit using drain valves, and gauges should read zero before any bolts are loosened. Bolts should be removed in a crisscross pattern to avoid warping the plates. Each plate should be removed carefully without using metal tools, and stored upright in the correct order for reassembly.