What function does overfill prevention equipment serve in underground storage tanks?

Overfill prevention equipment in underground storage tanks is designed to automatically shut off the flow of product into the tank when it reaches 95% of its capacity. This critical function helps to prevent spills and overflows that can occur if a tank is filled beyond its capacity, which could lead to environmental contamination, safety hazards, and regulatory violations.

By activating at 95% full, the equipment ensures a sufficient buffer remains to accommodate any additional volume, such as from temperature expansion or liquid surge during filling. This proactive measure is essential for maintaining both safety standards and compliance with environmental regulations related to UST operations. The significance of this equipment is underscored by regulations that mandate its use to minimize the risk of accidental releases into the environment and to protect public health.