Underground Tanks Tightness Testing

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Tanks tightness

Tightness Testing on Underground Storage Tanks and other Air Tight Compartments

The ability to test for tightness with an ultrasound detector is extremely powerful and versatile. It is the only way to ensure that underground storage tanks are air tight. But that isn’t all that ultrasonic tightness testing can be used on. In fact, there are many things that need to be air tight. Like the engine or cabin of a car, large shipping containers or the bearing housing in a paper production plant. When something’s tightness integrity deteriorates, one or two things can happen. Things can leak out, or things can get in. And whenever possible, it is advantageous to avoid either of these from happening for ecological and environmental reasons for a start.

Fuel Leaking From Domestic Underground Storage Tanks Damage the Environment and Waste Valuable Resources

Overtime the tightness integrity of underground storage tanks or other air tight compartments can deteriorate. Or… they were never air tight to begin with. This is why tightness testing is an essential maintenance task to be carried out on underground storage tanks to prevent leaks that are wasteful and harmful to the environment. Indeed, leaking underground storage tanks result in contamination of the surrounding soil, groundwater and surface water. Not to mention, the loss of resources through the leak.

Underground tank testing with ultrasound simultaneously evaluates the tightness of the tank and the piping without opening the manhole. The SDT device detects leaks in domestic underground fuel storage tanks thanks to the Guided Mode embedded in its firmware, escorting you through the standard procedure step-by-step. Use guided mode to add visual information useful for report creation such as the liquid level, the tank’s diameter, and much more.

The SDT TankTest Reporter provides tank owners with a comprehensive report detailing their tank condition.

Since 1995 SDT has been the world leader in underground tank tightness testing. SDT developed the most comprehensive and accurate system for performing underground tank tightness inspections. A method that various accrediting agencies in Belgium, France and the United States have tested and approved. This proven method has been used to perform thousands of inspections world-wide.

Why use Ultrasounds? 

Ultrasound capabilities lie with detecting any defect that creates friction. But what happens when there is no high pressure gas leaking through some piping? What happens when there is no turbulence? SDT has a solution for that. The sensitivity of the SDT device and the associated sensors offer the system’s unequalled accuracy.

It detects even the smallest perforations or “mini defects” not yet generating a significant degree of pollution. It allows you to locate a tightness problem, on the tank, around the manhole cover, on the pipes and on connections. With our SDT device, you can now keep track of all events during a test, thanks to a histogram that works for both sensors.

How SDT’s Underground Tank Testing Method Works

Ultrasonic tightness testing consists in collecting and amplifying the sounds generated by leaks further to the depressurization of the tank, using two sensitive sensors.

  1. Two dedicated sensors are placed in the tank. One in the liquid and the other one above the surface of the liquid.
  2. The SDT ultrasound device measures background noise in the installation (reference value) in dBµV.
  3. The tank is placed in a partial vacuum.
  4. Diagnosis is issued based on a comparison between the reference value and the measurements obtained from each sensor. You can keep track of all events during the test thanks to an histogram that works for both sensors. Check each sensor’s measurements data directly on the SDT device.
  5. This diagnosis is then confirmed by the operator who is listening to the sound of the leak.
  6. The recording time of measurements and audio files is defined based on the operator’s needs.
  7. Very flexible operation regarding recording time and momentary stops.
  8. Consultation of the dBµV values and playback of the audio files are available at any time from the device memory.

The SDT acoustic method is straightforward and provides immediate results.

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TankTest Reports

With the SDT TankTest Reporter software, you can now create simple and effective reports. These will allow you to quickly document your tanks tightness testing data and communicate them to anyone concerned in an easily accessible and understandable Microsoft Word format. This software can be installed on a Windows tablet to offer you the possibility to send your report immediately to your customer.

Download the SDT TankTest Reporter software Manual

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Questions concerning Underground Tanks Tightness Testing

The ability to use an ultrasonic detector to assess for tightness is incredibly powerful and adaptable. It makes it possible to ensure the tightness of underground storage tanks without having to empty them. Ultrasonic tightness testing consists in collecting and amplifying the sounds generated by leaks further to the depressurization of the tank, using two sensitive waterproof sensors placed in the tank. One is placed in the liquid and the other one above the surface of the liquid. The SDT ultrasound device then measures background noise in the installation and compares fluctuations of the dBµV values in both medium (air and liquid) with the initial readings (before partial vacuum). Important fluctuations and/or other unusual noises put tightness issues in evidence.

Tank tightness testing is essential for energy and cost savings, as well as to keep the tank’s integrity from the elements. It is also a good way to ensure environmental friendliness.

Contamination of the surrounding soil, groundwater, and surface water occurs as a result of leaking underground storage tanks, putting the environment and people living nearby at danger. Not to mention the resources lost as a result of the leak.