Specialist for hydrogen leaks

VARIOTEC 460 tracer gas in use
 

• The pipe, (or any item you wish to test for leaks), with the leak, is emptied of its contents. In heating or water systems drain out as much water as possible; small amounts of water remaining at low points of the system do not dramatically affect the success as the gas is pressurised around the water system.
  Ensure the system is sealed. i.e. no gas can escape except via the leakage point
• From a cylinder of Tracer gas, (5% hydrogen / 95% nitrogen, provided by standard compressed gas suppliers), make  a suitable connection to the item to be filled with gas.
• The pressure you use will depend on the normal operating pressure of the system being tested for leaks and how high you wish to pressurise.
• When the cylinder pressure gauge steadies you know that any subsequent pressure loss of tracer gas can only be via a leak
• With the Variotec 460's  internal sampling pump turned on, (this positive sampling of the air speeds up response time), walk over the area to be searched with the Variotec 460 on its most sensitive setting (ppm). Observe the display looking for the location with the highest tracer gas readings.
• Move away from the area that showed the highest gas readings and see that the display drops
• Return to the area that showed the highest reading and check the gas display once again increases
• Check other areas for high readings

Note: The above information is for generic guidance only and  is not to be considered as instructions for how to operate or implement the use the Variotec 460

Why use hydrogen as the tracer gas?
Hydrogen, at a level of 5% in a balance of nitrogen, is:

• non flammable
• non toxic
• non corrosive
• totally safe
• commonly used as a blanket gas in welding so is cheaply and readily available from all the standard gas suppliers
• has the smallest and lightest molecules so permeates all surfaces including concrete, tarmac, block paving and grass, rising quickly to the surface
  rapidly disperses in air allowing you to hone in quickly to the source
• unlike helium leak detection, which has also been used for some types of leak detection tracing, hydrogen is renewable and cheap; helium is finite and expensive