What psi backpressure does the pressure relief control maintain on the high level shutoff valve on a Type 4 underground operating storage tank?

The pressure relief control on a Type 4 underground operating storage tank is designed to maintain a specific level of backpressure on the high level shutoff valve. Maintaining this precise backpressure is crucial for ensuring safety and proper functioning of the tank system.

In this case, the correct backpressure of 8 psi is significant because it helps prevent overfilling and the associated risks of spills or leaks, which can have serious environmental and regulatory implications. This level of backpressure allows for effective regulation of the flow and storage of fuel, supporting system integrity and operational efficiency.

The other stated pressures are not sufficient to achieve the necessary control and safety measures for this type of tank configuration. Lower psi values may not adequately counteract potential pressures from fuel delivery systems, potentially compromising safety and operational standards. Therefore, an understanding of these specifications is critical for anyone involved in the maintenance and operation of water and fuel systems.