Shanghai Fengxian Equipment Container Factory registered the trademark of "Jiang Shen" and is a professional supplier of Jiang Shen brand gas storage tanks. Our company provides the following knowledge: Generally, pressure vessels should be inspected for the first time after being put into use for three years. There will be an inspection cycle in the future.

(1) For pressure vessels under any of the following circumstances, the inspection cycle of the whole machine shall be shortened appropriately:

1. The corrosion of the medium to the pressure vessel material is unknown or the corrosion rate of the medium to the material is greater than 0.25 per year, and the corrosion data determined by the designer is inconsistent with the actual situation;

2. The surface quality of the material is poor or there are internal defects;

3. Poor service conditions or stress corrosion found during use;

4. It has been used for more than 20 years, and it can't be used safely according to the normal inspection cycle after being confirmed by technical appraisal or inspection personnel;

5. Stop using for more than 2 years;

6. Changing the medium used may worsen the corrosion phenomenon;

7. The design drawings show that the pressure test cannot be carried out;

8. There are doubts about other factors affecting safety during the inspection;

9. If the medium is liquefied petroleum gas and there is stress corrosion, the whole machine should be inspected every year or as needed;

10. The steamed ball without anticorrosion measures by "ammonium sulfite method" shall be inspected at least once a year as required;

1 1. Spherical storage tank (made of materials with standard lower limit of tensile strength fb≥540MPa, which should be unpacked and inspected after one year of use);

12. Glass lining equipment.

(2) When the pressure vessel with safety status grade of 1 2 meets one of the following conditions, the inspection cycle of the whole machine can be appropriately extended:

1. The nonmetallic lining layer is intact, and the longest inspection period can be extended to 9 years;

2. If the corrosion rate of medium to materials is lower than 0. 1 (measured data) every year, and there is a reliable corrosion-resistant metal lining (composite steel plate) or thermal spraying metal (aluminum powder or stainless steel powder) coating, the inspection period can be extended to 1-2 years at the longest after1-2 machine inspections;

3. The inspection cycle of the reaction kettle with catalyst and the large pressure vessel with filler shall be determined by the user, the design unit and the inspection institution through consultation according to the design drawings and actual use, and reported to the quality and technical supervision department that has handled the use registration certificate for the record. The cumulative monitoring time of pressure vessels with safety status grade four shall not exceed 3 years. During the monitoring period, the defects should be treated to improve their safety level, otherwise they should not be used again.