Haihao Group takes you to understand the inspection of pressure vessel flanges

In the petrochemical industry, pressure vessels play a crucial role, with pressure vessel flanges being essential components. To ensure their safe operation, pressure vessel flanges need to undergo a series of rigorous inspection procedures, including internal and external inspections, as well as a final inspection.

Internal and External Inspection: This inspection must be conducted while the vessel is at a standstill and has been thoroughly cleaned internally. The inspection includes observing the external surface and checking for corrosion and wear on both the inner and outer surfaces. Weld seams, head transitions, and other stress concentration areas also require careful examination to ensure there are no cracks. If necessary, ultrasonic or radiographic testing may be performed. Through internal and external inspection, any defects can be promptly identified and addressed to ensure the integrity and safety of the vessel.

Weld neck flanges WN flanges A182 Gr F347 RTJ ASME B16.5

External Examination: This inspection, also known as in-service inspection, involves observing whether there are any abnormal phenomena such as cracks, deformations, or leaks on the external surface of the vessel. The integrity and reliability of safety accessories and the status of fastening bolts are also checked. External inspection is typically conducted jointly by inspectors and operating personnel to ensure the vessel’s normal operation.

Final Inspection: In addition to the above inspection items, the final inspection includes a hydrostatic pressure test and non-destructive testing of weld seams. The hydrostatic pressure test is usually performed using a water pressure test. For vessels with lower pressures, non-flammable, non-toxic, or non-corrosive media, the final inspection period may be appropriately extended after obtaining some operational experience.

These inspection procedures ensure the quality and safety of pressure vessel flanges, enabling them to meet the stringent requirements of the petrochemical industry. Haihao Group is committed to producing high-quality, reliable pressure vessel flanges, providing our customers with safety assurance.