Fluorescent powders for pressure vessel inspection: What aspects of pressure vessels are inspected in H2S and wet H2S environments, and what is the inspection frequency?

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For pressure vessels in H₂S and wet H₂S environments, corrosion damage must be carefully inspected, with a recommended initial inspection interval of 1–2 years. Such environments are prone to hydrogen sulfide stress corrosion cracking (SSCC); during inspections, special attention should be paid to: material degradation detection – using fluorescent magnetic particle or penetrant testing techniques to identify microcracks on the inner walls of containers and in weld areas, with particular focus on areas where stress concentration occurs. Wall thickness measurement: An ultrasonic thickness gauge is used to monitor the corrosion-induced thinning in key areas, in order to assess the remaining strength. Environmental control verification: Check whether parameters such as H₂S concentration, pH value, and moisture content in the medium are within safe ranges to prevent increased corrosion. In accordance with industry standards, for newly installed pressure vessels operating in a wet H₂S corrosion environment, the first comprehensive inspection should be conducted within 1–2 years, with subsequent inspection intervals adjusted dynamically based on the results of risk assessments. For media with an extreme or high level of toxicity, more stringent pressure resistance tests and emergency response plans must also be implemented.