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ASF Leak Detector Type D29 - Pressure Principle


  • The leak detector is used to monitor non-pressurized underground/aboveground double-walled pipelines.
  • For monitoring of water-polluting liquids, and flammable liquids having a flash point of < 55°C.
  • The interstitial space of the double-walled pipeline must be suited for the connection and operation of this leak detector.
  • The leak detector can be used for monitoring of several underground pipelines utilizing a manifold.

The leak detector must be mounted outside the hazardous area (ex-zone)!


Product images

D29_2Operating Conditions

  • The double-walled pipelines must be depressurized.
  • Leak detection fluid may not be present in the interstitial space of the container.
  • Appropriate manifolds together with a D29 leak detector may only be used for monitoring underground pipelines.


  • Installation of a potential free relay.
  • Installation in protective casing with exterior alarm and heating.
  • Mounting kits for connection to pipelines and manifolds.


Dryer / Drying Beads


By default, with V = 180 cm3

Selection of the air dryer for aboveground applications can be found in the technical description.


  • Leak detector according to the principle of positive pressure with integrated pump and pressure relief.
  • The outside air is sucked through a vessel with dry beads (air dryer), which dries the air down to a relative humidity of <10%.
  • The saturation of the dry beads, depending on the humidity, is reached in about 12-15 months, identifiable by the color change, - initially orange - colorless at saturation.

Switching Values:

Alarm On PAE = 1,1 bar

Pump Off PPA = 1,5 bar

Overpressure Protection

Pressure relief valve of the pump opens at

PSV = 1,65 bar

For further data please see the data sheet of the D29 leak detector.

Mounting Examples

Please click on the picture for a larger view!




ASF pdfInstallation and Operation Manual D29

ASF pdfData Sheet D29

ASF pdfD29 Accessories & Assembly Kits