Test A Compressed Air Tank

Compressed air cylinders should be checked before every use.

Compressed air tanks are built to carry high-pressure air. Therefore, to avoid accidents, they must be inspected for safety every time they are used. Common uses for compressed air cylinders include scuba tanks and auto shop tire inflators. Accidents that could happen with compressed air range from blown discs to explosion, meaning the safety inspection is critical.



1. Locate the o-ring on the valve of the tank. Check that it is intact without cracks and seated correctly in the valve.

2. Examine the exterior of the tank for any visual problems such as dents or cracks in the structure.

3. Check the hydrostatic test date. On most cylinders, this is stamped on the neck of the tank. Make sure that it is within local regulations. This is within five years in the United States as of 2010.

4. Check the external visual inspection sticker for a date. Visual inspection is necessary every one to two years, depending on local law. Outdated visual inspection tickets make it difficult to obtain refills without being re-inspected.

5. If the tank contains oxygen or enriched air, then attach an oxygen analyzer and slowly turn on the valve, to obtain an oxygen percentage reading. It should contain a reading to within 1 percentage point of the desired mix. Once you have this, slowly turn off the valve.

6. Attach the regulator first stage to the tank valve.

7. If the tanks contains breathing gas then analyze the gas by breathing from the regulator second stage attached to the tank. The gas should be tasteless and odorless. The presence of taste or odor might indicate internal corrosion or oil in the compressor.

8. Close the valves and depressurize the system by using the purge valve on the regulator second stage.

9. Disassemble the unit carefully if transporting the equipment.