Simple operation-Insert air injection gun into tube. Squeeze the pistol grip; seal expands andlocks into the tube.  Then a push of the air control button clears the tube of loose dirt and scale, and shows the plugging gun operator which tube is being tested.  (No need to count tubes to locate the right one).

Insert plugging gun into tube, and squeeze the pistol grip to lock seal. Sealing elements seal within 1/2" (12.7 mm) of the tube bundle end so leaks or breaks inside the tube sheet can be detected. (Most leaks occur at this point due to dissimilarity of metals).

5256 Tube Testing Kit includes:  Air injection gun, plugging gun, compression tubes, and seals for one specific tube size.  Accessories shown below are available to adapt guns to other tube sizes.