TIB 40 – 212062
All locating procedures are ultimately based on acoustics.
These procedures are increasingly finding their limits. Worsening factors include,
for example, the increasing „environmental contamination“ by disruptive noise, even
at night. Acoustic measuring points (fittings) are economised on. This extends the
length the sound needs to bridge. Plastic lines are especially difficult, as they
inherently conduct sound poorly.
What is new in comparison to the classic tracer gas procedure?
To date the line to be tested had to be taken out of operation and evacuated. This involved a lot of effort and expense, often accompanied by the frustration of those connected due to the supply interruption. There is also a risk that germs can infiltrate and find their way into the depressurised line.
An approved, detectable gas with a hydrogen proportion of approximately five percent is added to the flow of water in the network section to be tested. The proportion of the additive is in turn oriented to the prevailing water temperature and the water pressure and lies between two and more than ten percent of the water flow rate. This amount can be easily absorbed in the water and causes no problems during running operation in terms of distribution. Even if the leak is located in the most unfavourable position, at the invert, the water-gas mixture exits there. Gas and water then separate as a result of relaxation, like with bottled carbonated water. In order to optimally trace the gas and thus the leak, the soil is vacuumed with a strong and mobile vacuum probe. A highly sensitive hydrogen detector detects the gas proportions and displays the exact position of the leak.
- Line stays in operation
- No interruption of supply
- The line remains under operating pressure