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Inspection contents: (1) The inspection primarily involves visual inspection, wall thickness measurement, and inspection of the inner surface; other non-destructive testing methods may be used if necessary； (2) According to the corrosion mechanism and operating conditions, inspect the pressure vessel body, butt welds, and pipe corner welds for cracks, deformation, bulging, leakage, etc. Special attention should be paid to stress concentration areas, the vapor-liquid interface, deformed areas, welds between different steel grades, repair welding areas, weld marks from fixtures, and areas damaged by arcs ； (3) Check for corrosion and mechanical damage on the inner and outer surfaces ； (4) Check whether the structure and geometric dimensions meet the requirements ； (5) Check whether the wall thickness has thinned. The locations for measuring the thickness are generally selected from the following areas: 1) Areas where the liquid level fluctuates frequently ； 2) Areas prone to corrosion and erosion ； 3) Areas where the wall thickness is reduced during manufacturing and molding, and areas prone to deformation during use ； 4) Suspected areas identified during surface defect inspection ； 5) Connection point ； (6) Check the weld for any hidden defects ； (7) Check whether the material meets the requirements ； (8) Check the flange sealing surface for cracks ； (9) Check the condition of the fastening bolts; bolts that are to be reused should be cleaned one by one, their damage checked, and surface non-destructive testing performed if necessary. Special attention should be paid to checking for circumferential cracks in the threads and transition areas ； (10) Check for damage to supports or bearings, as well as settlement, tilting, and cracking of the foundation of large containers ； (11) Check for any damage to the insulation layer, heat insulation layer, and lining, as well as any peeling of the surfacing layer ； (12) Check whether the safety accessories are sensitive and reliable ； (13) Key inspection areas and contents for various types of pressure vessels. For heat exchangers, the main areas that need to be inspected include the tube sheet, tube box, heat exchange tubes, baffle plates, shell, anti-surge plates, small floating head bolts, small floating head covers, nozzles, and connection flanges. Pay special attention to inspecting the following areas: the pipe ends at the heat inlet on the tube side where erosion and cavitation are likely to occur, the shell side tube sheets prone to crevice corrosion, as well as the shell side inlet and outlet susceptible to erosion ； Tube sheets and heat exchange tube sections prone to pitting, crevice corrosion, and stress corrosion ； Places where the flow direction of the medium changes, such as the inlet of heat exchange equipment, anti-overflow baffles, the shell at the location of baffles, and the U-turns in shell and tube heat exchangers ； Check for cracks at the stress concentration areas of the housing ； Check the wall thickness of the heat exchange tubes ； f. Inspect the take over and flange sealing surfaces. For towers, pay special attention to the following areas: a. Areas where moisture, humidity, corrosive gases accumulate, or at the liquid-vapor interface ； b. Logistics \"dead zones\" and erosion areas ； c. Welds and heat-affected zones ； d. Areas where stress corrosion and hydrogen damage may occur ； e. Flange transition areas and stress concentration zones ； f. Internal components prone to corrosion and deformation (trays, beams, distribution plates, oil collection tanks, etc.) ； g. Internal components such as defoamers, defoaming nets, distributors, vortex generators, and heaters ； h. Connection site ； i. Check the metal lining for corrosion, cracks, local bulging, or dents. For the reactor, focus on inspecting the following areas: a. Check for cracks in the reactor’s butt welds, pipe connection fillet welds, and the protrusions on the support rings ； b. Check the flange seal groove for cracks ； c. Check the cold wall reactor lining for any peeling, holes, cracks, pitting, or looseness ； d. Check the surfacing layer of the hot-wall reactor for surface cracks, subsurface cracks, and delamination ； e. Check for cracks in the reused fastening bolts ； f. Check the support beams, distributor blisters, and thermocouple sleeves for cracks and other defects ； g. Inspect other internal components.