Overpressure in isolated relief valve body and downstream piping

摘要

A gas terminal operator planned to upgrade a high pressure processing plant's pressure protection system from single to dual pressure safety valve (PSV) sets. This was to allow on-line valve changes for calibration and maintenance and to avoid the need to shut down for this activity. Due to limited space in various locations, the use of 'changeover' valves was seen as an attractive option to simplify the isolation control required for safe changeover.