Hydrogen leak testing is a method to find leaks in underground piping and cables. Subsurface leaks can be difficult to find for obvious reasons. Using a mixture of hydrogen gas ( 5% H2 mixed with 95% N2 as a tracer) put into the pipe or cable allows the hydrogen mixture to escape from the leak location and make its way to the surface where the leak location can be identified with our Hydro-Lok Hydrogen Leak Detector.
Why Use Hydrogen as the tracer gas?
- Hydrogen is very high energy gas and a small molecule
- Background of hydrogen in air is very low thus provides good leak resolution
- Low cost gas that is abundantly available and can be created
- Hydrogen sensor offers great durability and robustness
- Sensor while very sensitive to hydrogen is relatively inexpensive
What Applications Can the Hydro-Lok be used?
- Underground Water Lines
- Underground Gas Lines
- Telecommunication Lines
- Swimming Pools
- Steam Lines
Where to Use the Hydro-Lok as an Underground Pipe Leak Detector
- Isolate the underground line so that the hydrogen tracer gas mixture can be released into the pipe.
- Determine the depth the pipe is below the ground and the type/density of the underground soil/material.
- If the pipe is 2 ft. underground, it may only take 30 minutes for the tracer gas to surface. If it is much deeper and the material is say concrete, the period could be as long as overnight.
- Inject the hydrogen tracer gas into the line pressurizing as much as possible without damaging any component in the piping system, Pressure is a major factor in leak rate. But keep in mind that leaking water lines expel a lot of tracer gas.
- Once you feel the tracer gas has surfaced, walk the line of the pipe, probing every foot or so until a leak is detected.
- Measure the leak rate in the area where indicated closely and determine the point of highest reading.
- The leak should be located within a 3 foot circle of where the highest leak rate is indicated.