When trans-filling an SCBA cylinder, follow these rules:

Rapidly trans-filling an SCBA cylinder (charging an empty cylinder from another higher-pressure cylinder) can be accomplished safely if a few simple rules are followed.

1. As with any cylinder filling process, the cylinder should be inspected prior to filling to insure there is no visible damage to the fiber overwrap or metal neck. If damage is detected, do not fill the cylinder. Take it to a DOT or TC authorized hydrostatic retester for inspection and testing. Locate the retester facility nearest you.

2. Check the cylinder label to insure that the cylinder is within its hydrostatic test service period (five years for DOT carbon wrapped cylinders, 3 years for TC carbon cylinders). Do not fill the cylinder if it needs to be hydrotested.

3. When filling, do not exceed the cylinder's rated service pressure.

Finally, filling cylinders using a compressor or intensifier will result in the heating of the air in the cylinder. If the cylinder significantly increases in temperature during the filling process, slow the filling rate down. As a general rule, do not fill from a compressor at a rate that results in the cylinder heating to over 140°F (too hot to hold in a bare hand).

Any questions concerning the safe filling or use of these composite cylinders should be directed to Carleton Technologies Inc. Phone 410-760-9856.


DOT: US Department of Transportation, regulatory agency for US users.

TC: Transport Canada, regulatory agency for Canadian users.