California ICC UST Service Technician Practice Exam 2025 – All-in-One Guide to Ensure Exam Success!

Automatic Line Leak Detectors (ALLDs) are specifically required for pressurized piping systems. This is because pressurized piping is susceptible to leaks that can lead to significant environmental contamination and safety hazards. ALLDs continuously monitor the pressure within the pipes and can detect any deviations that could indicate a leak.

In contrast, gravity piping systems typically do not require this kind of monitoring because they operate under the principle of gravity flow, which does not generate the same pressure conditions that may lead to rapid leaks. The focus of leak detection in gravity systems often involves different methods that are more suited to their operational characteristics.

Understanding the distinction between these piping systems is critical for maintaining compliance with regulatory standards and ensuring the safety and integrity of the entire fueling system.