Hydrogen as a Tracer Gas for Underground Pipe Leaks
The tracer gas method for locating underground pipe or pipeline leaks has been around for many years. Original technology was with a helium leak detector. Helium tended to be difficult to justify using as the helium mass spec is a very complex instrument that is very expensive. Helium while a small molecule is expensive as it is a gas that is mined along with natural gas.
In the 1990's telecom rush to lay optical fiber for broadband internet, technology for hydrogen was improved to provide an alternative for helium. Once that boom ended in the early 2000's the hydrogen detection method cooled due to the lesser demand. At the time, cost was a factor and only the most lucrative applications could justify the equipment. Several companies, mostly in Europe, also developed less expensive detection equipment, to fuel the demand for locating water leaks.
Hydrogen is a very good gas for tracer detection. As hydrogen leak detectors improved in technology, the ability to reduce the concentration to 5% H2/95% N2 fueled the change from helium. The 5%H2/95% N2 is approximately 25% the cost of helium. To reduce cost, always ask for industrial grade 5%H2/95%N2 with no certificate needed. It is not important that the tracer gas be 99.999% pure nor do you need that certified. Always ask though as gas companies tend to provide the research grade gas. the 5%H2/95%N2 is completely non-flammable and non-combustible. It is a totally environmentally friendly gas.
Hydrogen as a tracer is an ideal gas. Hydrogen is high energy and tough to contain. This works well for leaking from an underground pipeline as the hydrogen can penetrate both asphalt and concrete. Hydrogen also moves straight up and the leak should be able to be located above ground in a 3ft. circle. Depending on the depth of the pipeline, the hydrogen mixture may need to be put in the pipe the night before. For water pipes near the surface, 30 minutes can be sufficient.
Feel free to call us with any questions. Schoonover provides a low cost hydrogen leak detector called the Hydro-Lok. Cost of the Hydro-Lok kit including regulator, probe stick and lines are priced at $1499. Our aim is to provide a quality low cost hydrogen leak detector priced for all leak detection professionals to be able to take advantage of the technology.