Pressure vessel inspection
(1) External inspection of pressure vessels
Also known as in-service inspection, the main contents of the inspection are: abnormalities on the outer surface of the pressure vessel, such as cracks, deformation, leakage, local overheating; whether the safety accessories are complete, sensitive and reliable; whether the fastening bolts are intact and all tightened; Whether the foundation has any abnormalities such as sinking, tilting, and damage to the coating. The external inspection is both the work of the inspector and the daily inspection of the operator. It is found that the safety phenomenon (such as cracks, deformation, severe leakage, etc. of the pressure component) should be stopped and reported to the relevant personnel in time. (2) Internal and external inspection of pressure vessels
Internal and external inspection of the pressure vessel This inspection must be carried out after the parking and the inside of the container have been cleaned. The main contents of the inspection include, in addition to the entire contents of the external inspection, the corrosion of the inner and outer surfaces; the naked eye and the magnifying glass: check all welds, head transition areas and other stress concentration parts for cracks, if necessary, Ultrasonic or radiographic inspection checks the internal quality of the weld; measures the wall thickness. If the measured wall thickness is less than the minimum wall thickness of the container, the strength check should be re-examined, and the pressure-reducing use or repair measures should be proposed; for the container that may cause the metallographic structure change of the metal material, metallographic examination should be carried out if necessary; The main bolts of ultra-high pressure vessels should use magnetic powder or coloring
The pressure vessel is inspected for cracks or the like. Through internal and external inspections, the defects should be analyzed and the treatment opinions submitted. A retest is required after repair. The internal and external inspection cycle of the pressure vessel is once every three years, but the inspection period of the container for strongly corrosive media and highly toxic media should be shortened. Containers with severe defects found during operation and containers with poor weld quality and materials whose corrosion resistance is not known should also shorten the inspection cycle. (3) Comprehensive inspection of pressure vessels
The pressure vessel is fully inspected in addition to the above-mentioned inspection items, and a pressure test (generally a hydrostatic test) is also carried out. Non-destructive testing of all major welds or inspection of all welds. However, for containers with low pressure, non-flammable or non-toxic, non-corrosive media, if no defects are found, after obtaining certain experience, non-destructive testing may be performed. The full inspection cycle of the container is generally performed at least once every six years. For qualified containers filled with air and inert gas, the full inspection cycle may be extended after obtaining experience and one or two internal and external inspections to confirm that there is no corrosion.
