Why Are SCUBA Tanks Placed in Water for Refilling?

Why Are SCUBA Tanks Placed in Water for Refilling?
A common practice when filling SCUBA tanks is to submerge the cylinder in water. This practice is primarily done to increase the rate at which the SCUBA tank can be filled.

Pressure and Temperature

When SCUBA tanks are filled, the increasing pressure inside the cylinder produces an increase in temperature.

Water as a Coolant

The water surrounding the SCUBA tank conducts heat away from the cylinder better than air.

Reduction in Temperature Rise

This transfer of heat away from the SCUBA tank reduces the rate at which the temperature will rise during the filling process.

Maximum Fill Rate

Reducing the rate of temperature increase allows the maximum fill rate to be increased, shortening the amount of time needed to fill the SCUBA tank.

Warm Tank vs. Cool Tank

A warm tank holds less air at a given pressure than a cool tank at the same pressure. This means as the tank cools, the pressure of the air inside of the SCUBA tank will also decrease. Controlling the temperature of the tank during the fill process can increase the amount of air available during the next dive.

Article Written By David Chandler

David Chandler has been a freelance writer since 2006 whose work has appeared in various print and online publications. A former reconnaissance Marine, he is an active hiker, diver, kayaker, sailor and angler. He has traveled extensively and holds a bachelor's degree from the University of South Florida where he was educated in international studies and microbiology.

Write for Trails.com
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