Stainless steel tank inspection includes external inspection, internal inspection inspection. The periodic inspection of stainless steel tank shall be determined according to the technical service conditions of the tank.

　　Generally, the external inspection shall be at least once a year, the internal inspection shall be at least once every three years, the inspection shall be at least once every six years. If the service life of stainless steel tank is more than 15 years, internal external inspection shall be conducted every two years. If the service life is 20 years, internal external inspection shall be conducted at least once a year.

　　1、 Internal inspection

　　1. Whether there is corrosive wear on the inner surface manhole connecting pipe storage tank, whether there is crack in the weld, head transition area other places with stress concentration;

　　2. When there is corrosion on the inner outer surfaces of the tank body, the wall thickness of the suspected parts shall be measured at several places. If the measured wall thickness is less than the designed small wall thickness, the strength verification shall be carried out again, suggestions on whether to continue to use allow high working pressure shall be put forward;

　　3. When the inner wall of the tank has decarbonization, stress corrosion, intergranular corrosion, fatigue crack other defects, the metallographic inspection surface hardness measurement shall be carried out, the inspection report shall be provided.

　　2、 External inspection

　　1. Check whether the anti-corrosion layer, insulation layer equipment nameplate of the storage tank are in good condition, whether the safety accessories control devices are complete, sensitive reliable;

　　2. Whether there are cracks, deformation local overheating on the outer surface;

　　3. Whether there is leakage in the nozzle weld pressure element, whether the fastening bolt is in good condition, whether the foundation sinks tilts.

　　3、 Inspection

　　1. The main weld shell shall be inspected without damage, the spot check length shall be 20% of the total weld length;

　　2. After passing the internal external inspection, the water pressure test air tightness test shall be conducted according to 1.25 times of the design pressure of the tank. During the above inspection, it is qualified if there is no leakage at the welds of the storage tank each part, there is no visible abnormal deformation of the storage tank;

　　After the inspection of stainless steel storage tank is completed, a report shall be made on the inspection of storage tank, indicating the problems reasons that can be used continuously can be used continuously but need to be repaired can be used. The inspection report shall be kept for future maintenance.