The inspection period for liquefied petroleum gas storage tanks is stipulated as follows:
Period of external inspection of liquefied petroleum gas storage tanks: at least once a year;
The internal and external inspection period is divided into: if the safety status is 1-3, at least once every 6 years; if the safety status is 3-4, at least once every 3 years;
For liquefied petroleum gas storage tanks with one of the following conditions, the internal and external inspection period should be appropriately shortened:
The corrosion status of the medium to the pressure vessel material is unknown, the corrosion rate of the medium to the material is greater than 0.25 (mm/year), and the corrosion data recognized by the designer is seriously inaccurate; the material has poor welding performance and has been repaired many times during manufacture ;Initial inspection; Poor use conditions and low management level;
The use period exceeds 15 years, and it is recognized through technical appraisal that it cannot be used according to the normal inspection cycle; the inspector believes that it should be shortened.
For liquefied petroleum gas storage tanks with one of the following conditions, the internal and external inspection period can be appropriately extended:
The inner layer of non-metallic materials is intact, but the inspection cycle should not exceed 9 years;
The corrosion rate of the medium to the material is lower than 0. 1 mm/year or pressure vessels with reliable corrosion-resistant metal fabrics, which have passed one or two internal and external inspections and are confirmed to meet the original requirements, but should not exceed 10 years;
The regular inspection cycle of the reaction vessel with catalyst and the large liquefied petroleum gas storage tank with filling shall be approved by the user unit according to the design drawings and actual use conditions.
Period of withstand voltage test: at least once every 10 years.
- For liquefied petroleum gas storage tanks with one of the following conditions, the pressure test must be carried out after the internal and external inspections pass:
- Repairing or replacing main pressure components by welding;
- Change the conditions of use and exceed the original design parameters;
- The replacement material is in front of the new fabric;
- Stop using the ones that have been reused from scratch for two years;
- Newly installed or relocated liquefied petroleum gas storage tanks;
- Unable to conduct internal inspection;
- The user has doubts about the safety performance of the liquefied petroleum gas storage tank.
If the internal and external inspection or pressure test cannot be carried out on time due to special conditions, the unit using the liquefied petroleum gas storage tank must state the reasons and submit an application three months in advance. The inspection and approval of the department can only be extended after the labor department that issues the “Pressure Vessel Use Certificate” is on file, but generally it should not exceed 12 months.
