How to Check for Pinholes In BA Low-Pressure Hose
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In recent classes conducted by the training division of the Orlando, Fla., Fire Department on protective breathing equipment, many cases of lowpressure hose deterioration were noted. Wear showed in a relatively short time in the grooves of the corrugated tubing, possibly because of heat encountered in fighting fires.
Because of the toxicity of many gases fire fighters encounter, mask and hose leaks cannot be tolerated.
The common method used to test for a seal of the mask and tubing by donning the mask, placing the end of the tubing in the palm of the hand, then inhaling slowly to check the seal appeared to be unreliable. When a vacuum is created in the hose, the holes have a tendency to close, preventing detection.
The training division, in searching for a simple, economical method for combat personnel to check the low-pressure hose, recommends the following procedure:
Step No. 1: Place No. 2 rubber stopper with the 1/8-inch hole in the end of the low-pressure tube that is metal. Next, place No. 3 rubber stopper in the end of the low-pressure hose with plastic connector.
Step No. 2: Stretch the low-pressure hose assembly, holding one end in your left hand and the other end in your right hand, to approximately 12 inches past its normal length.
Step No. 3: Place your thumb over the rubber stopper with the hole in it. Upon releasing the tension on the tubing with thumb in place, the air inside the hose will compress to about 3 psi.
Step No. 4: Submerge the low-pressure hose assembly in a container of water. This will indicate any holes or leaks in the assembly.
This method has been adopted by the Orlando Fire Department.
