Why Electronic PLLD for Detecting Line Leaks?

The Veeder-Root Electronic Pressurized Line Leak Detection (PLLD) system is designed to meet your everyday compliance needs. Our patented technology performs precision line leak testing at full pump pressure for 0.1 and 0.2 gallons per hour (gph) and a pressure decay test to meet the U.S. EPA 3.0 gph test requirements. The Veeder-Root Electronic PLLD system works in a variety of pressurized line applications, and offers flexible testing and digital reporting options, helping to detect catastrophic leaks. When paired with a TLS-450PLUS Automatic Tank Gauge (ATG), customers can monitor up to 1178 gallons of fuel line volume.

System Features

  • Pressure sensor is installed without breaking piping or adding a new sump, and is constructed with stainless steel to meet the challenges of a highly corrosive environment.

  • Test lines at full pressure for quick and accurate results, without restricting fuel flow rate.

  • Conducts a 3.0 gph test, which meets EPA and NFPA 30 release detection requirement for pressurized line systems, once all dispensing is completed to ensure the integrity of the line.

  • Standard 3.0 gph and optional 0.1 and 0.2 gph tests can be manually performed to reset alarms.

  • Monitors line pressure during dispensing activity to ensure a catastrophic leak is not occurring during a dispense. If a leak is detected at a pre-set pressure threshold, the system will shutoff power to the Submersible Turbine Pump (STP) to minimize environmental damage and prevent a public safety issue.

  • Built-in calibration verification to notify the site operator when the pressure transducer is not operating properly.

  • Auto-Confirm function, when enabled, runs a second line leak test, if an initial test failure occurs, to verify and reduce false alarms due to mechanical issues that may be occurring in other parts of the fueling system.

  • Provides two alarm shutdown options when failure occurs: Standard Dispenser Shutdown (Alarm and Shutdown)
    and Optional No Shutdown (Alarm Only).

  • Not impacted by thermal contraction of fuel in the line due to changes in temperature.

Product Form

TLS-450PLUS Line Leak Digital Transducer Part Numbers

Part Number



Digital Pressurized Line Leak Detector (DPLLD) without Swiftcheck Valve


Digital Pressurized Line Leak Detector (DPLLD) with Swiftcheck Valve


16 Input Universal Sensor Module (USM)


5 Universal Input/Output Interface Module (UIOM), Relay Control and Input Signal Monitoring


Ultimate Testing: Digital Line Leak Detection*


Risk Management: Digital Line Leak Detection*


Base Compliance: Digital Line Leak Detection*

TLS-350 Line Leak Analog Transducer Part Numbers

Part Number



Pressurized Line Leak Detector (PLLD) without Swiftcheck Valve


Pressurized Line Leak Detector (PLLD) with Swiftcheck Valve


6 Input Pressurized Line Leak Interface for use with PLLD Module


3 Output Pressurized Line Leak Controller


Ultimate Testing: Pressurized Line Leak Detection (PLLD)*


Risk Management: Pressurized Line Leak Detection (PLLD)*


Base Compliance: Pressurized Line Leak Detection (PLLD)*

* One per system required for precision line leak detection capability.

NOTE: The TLS-350 analog transducer is not compatible with the TLS-450PLUS ATG.


Operating Temperature

-25 ° F to +130 ° F

Compatible Fuel Types

  • Unleaded Gasoline

  • Leaded Gasoline

  • 5% Methanol

  • Up to 100% Ethanol

  • 15% MTBE

  • Diesel

  • Biodiesel (Up to B100)

  • Kerosene

  • Jet Fuel

  • Aviation Gasoline

  • DEF

Line Flow Rate

120 GPM Max w/ Swiftcheck Valve

Operating Range

0 – 70 PSI

Proof Pressure

200 PSI

Maximum Vertical Pipeline Height Above Transducer

11 Feet

Minimum Pump Output Pressure

23 PSI

Maximum Volume of Fuel Monitored

  • TLS-450PLUS - 1178 gallons
  • TLS-350 - 212 gallons

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