Testing A Freeze Out Valve

I recently had a customer contact me about an application where they were testing freeze out valves that go on the exterior of a locomotive.  The valve would be holding back about 45 psi of water in the pipe, and should open when the valve temperature reaches 35°F.  This would be used to keep any of the coolant / water lines from freezing during outdoor storage.

Mechanical Thermostat

The customer was using a chemical spray to freeze the mechanical thermostat and test that the valve opens.  Recently, an operator that was testing the valve used the wrong chemical and was hospitalized due to exposure so they decided it was time to change their testing method.

The customer purchased a Cold Gun Aircoolant System from our website, however, their compressed air temperature was 85-90°F and the Cold Gun is preset for a 50°F temperature drop at 100 PSIG inlet pressure. This means it wouldn’t quite reach the 35°F target reliably. Fortunately, EXAIR has a number of cooling products to cover an wide array of applications and our Adjustable Spot Cooler fit the application well since it can be adjusted to achieve much colder temperatures, up to a 100°F temperature drop from compressed air temperature.

EXAIR performed a test for the customer with the 25 SCFM generator installed and operated at 100 psig inlet pressure.   The valve was kept at a room temperature of 71°F and the compressed air inlet temperature was approximately 72°F.  The result was the valve would open in just under a minute.  This was even faster than the chemical test and it is adjustable to allow for the variance in the ambient temps. Success!

If you have any questions about how to use an Adjustable Spot Cooler in your application, please let me know.

Brian Farno
Application Engineer