13.03 What is line leak detection for piping?

Many State and local regulations require a line leak detector for pressurized underground piping. Line leak detectors for underground piping are used to detect a loss of integrity in the piping with a consequential shut down of the pump. There are 2 types of line leak detectors – mechanical and electrical.

Mechanical line leak detectors install on the submersible pump body. The pump must start against a closed valve to allow pressure to build in the line sufficiently to allow the line leak detector to open and flow. If pressure does not build in the line properly, then the mechanical line leak detector trips and restricts the pump flow.

Electronic line leak detectors operate in conjunction with a tank monitor such as a Veeder Root panel. After each pump run cycle, the panel turns on the pump automatically and measures the pressure in the line using a pressure transducer. The panel displays a pass / fail test result and may be required to be configured to disable th submersible pump.

Line leak detectors are designed to work reliably with motor fuel dispensing operations where dispensers include solenoid valves to work in conjunction with the submersible pumps. In emergency generator applications, especially mission critical applications, the devices can be problematic where test failures can shutdown the fuel supply system. Control systems need to include appropriate valve / pump timing controls to allow successful tests, and also detect failure and switch to a secondary pumps.