A dry sprinkler system? How will that help in a fire? The fire marshal snickered as he told me that this type of system was designed for cold weather fire protection.  Most sprinkler systems that we see in the ceiling are designed with water in the lines.  But, if you have areas that get below 40 deg. F (4 deg. C), the fire department will have you install a dry sprinkler system.  It uses compressed air to hold a valve shut to not allow the water to be inside the cold pipes. So, if you have an unheated crawl space, uninsulated attics, or an outside storage facility, you won’t have to worry about the water freezing and bursting your pipes or sprinkler heads.

The reason that the fire marshal contacted me was to help find a leak in a dry sprinkler system. A facility in his jurisdiction noticed that the air compressor that was assigned to the dry sprinkling system was cycling more often.  This was an indication of a leak, and just like any compressed air system, leaks occur over time at the connection points.  This facility had their pipes located in a crawl space, and there wasn’t much room for maneuvering.  Typically the normal protocol for a leak would be to go to each joint and spray it with soapy water.  If they saw bubbles, then they would fix that connection.  With the small space and the number of connections, he had to find a better way.

Whenever a leak occurs, it will generate an ultrasonic noise. The model 9061 Ultrasonic Leak Detector can pick up these high frequencies in the range of 20 Khz to 100 Khz, above human hearing.  This device makes the inaudible leaks, audible.  With three sensitivity ranges and LED display, you can find very small leaks, and with the two attachments, it can locate them up to 20 feet (6.1 meters) away.  When he started using it, he was amazed with the performance.  The Ultrasonic Leak Detector cut his time in the field and ensured that all the leaks were found.  In this instance, he was able to use the parabola attachment to locate the area of the leak from a distance.  He then crawled to that area and used the tube attachment to locate the exact location.  He found the leak and had it fixed.  If he did not have the Ultrasonic Leak Detector, he would have to maneuver his way throughout the small crawl space and spray soapy water on each fitting.

If you ever get stuck with a huge task with your compressed air system, like our fire marshal above, you can contact an Application Engineer at EXAIR to see if we can improve your situation.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb