First, a comprehensive inspection of the heat exchanger tube's appearance is performed, focusing on surface defects such as cracks, scratches, pits, bulges, scale, and rust. Welds should be inspected specifically for weld beading, incomplete penetration, porosity, and slag inclusions, as these defects can directly affect the tube's sealing and pressure-bearing capacity. For heat exchanger tubes exposed to corrosive media, special attention should be paid to inspecting the tube wall for uniform corrosion, particularly at vulnerable areas such as the inlet and outlet ports and U-bends, as these areas are often the first to show signs of corrosion thinning. Wall thickness measurement is a core inspection item. An ultrasonic thickness gauge is used to measure the heat exchanger tube at multiple points, focusing on tube-sheet joints and sections identified as problematic during previous inspections. The measured data should be compared with the original design wall thickness. Any wall...

First, during the material preparation phase, pipe cutting should be performed using a dedicated electric pipe cutter according to the design dimensions. The cut must be vertical, and pipes thicker than 3mm should be beveled at a 60-80 degree angle to ensure mechanical strength. After cutting, the pipe ends must be thoroughly deburred and the interior cleaned to prevent residue from damaging the passivation film and causing corrosion. For pipe sections requiring welding, the welded areas should be cleaned of grease and debris, and then symmetrically spot welded at 6-8 locations to ensure no misalignment of the pipe axis and that the butt joint gap is no greater than 2mm. Welding is a critical step in ensuring installation quality. TIG welding should be used with high-grade welding wire. During welding, the inner wall of the pipe should be protected with argon gas to prevent oxidation. After welding, the weld seam should be mechanically polished or pickled for passivation to resto...

Mechanical descaling is a common method. A flexible pipe cleaner, coupled to an umbrella-shaped, gear-shaped scraper, rotates and scrapes the inside of the condenser tubes, using circulating cooling water to remove scale and rust. The operation requires two passes, each with a blade diameter appropriate to the thickness of the scale. The first pass uses a blade slightly smaller than the pipe diameter to avoid damaging the pipe wall, while the second pass uses a blade closer to the pipe diameter to remove over 95% of the scale. Chemical cleaning uses a weak acid descaling agent that circulates for 24 hours to dissolve and remove scale. However, the solution concentration and cleaning time must be strictly controlled to prevent corrosion of the stainless steel substrate. For extreme scale buildup, high-pressure water jetting can be combined with high-pressure water jets, using 100-300 MPa to remove stubborn scale. This method is harmless to the pipe wall and does not cause chemi...