This tube to tube sheet joint testing kit uses two seals, one inside the tube and the other onto the tubesheet. Between these seals a vacuum is produced which in turn lets the operator know which tube to tubesheet joints are gas tight and non leaking. Features of the JTK-6500 Tube to Tube Sheet Joint Testing Kit Simple and reliable tube joint testing. Average 10 tubes per minute. Interchangeable seal sets for tubes up to 1.1/4"OD. Product weight 1.5 kg. Air supply 70 - 100 psi.