What must not exceed 95% during product delivery in UST systems?

In underground storage tank (UST) systems, the critical aspect that should not exceed 95% during product delivery pertains specifically to the set-points for delivery shutdown. Managing the fill level of a UST is crucial to prevent overfilling, which can lead to environmental hazards, product spillage, and potential violations of regulations.

Maintaining the fill level below 95% ensures that there is adequate vapor space within the tank, thus minimizing the risk of vapor release during delivery and preventing the escape of fuel vapors into the atmosphere. This practice is designed to protect both the environment and the facility from hazardous incidents, making adherence to this 95% threshold a key operational standard.

In contrast, while pressure levels, flow rates, and temperature thresholds are also important parameters in UST operations, they do not have the same direct correlation to preventing overfill scenarios as the set-points for delivery shutdown. Therefore, the focus on maintaining the appropriate fill level reflects best practices in safe UST management.