fig4 c that stop the movement of the ends of the tubes into the coupling so that the ends of the tubes abut each other and avoid forming an obstruction to the movements of the filter inserts and liquid passing through the aligned tubes and maintain the inserts aligned from one tube to its adjacent tube this spline design maintains the adjacent ones of the assembled tubes to be non rotatably connected to one another and allows for multiplied torque resistance during installation as shown in fig4 a 4 b and 4 c the steel pipe conduit of the penetrator tube 2 is inserted within the female coupling and may be welded at 36 to make a positive connection at the same time buttress welds 22 are made parallel to the longitudinal axis in order to increase the torque resistance necessary for installation as shown in fig4 b upon insertion of the male protrusion into the female receiver 39 s matching splines the coupling is made complete and the interior pipe diameters abut each within the coupling allowing for a continuous open annulus of the steel conduit a threaded recess tension bolt hole 33 is formed in the female coupling and becomes aligned with a matching smooth recessed tension bolt hole 32 formed in the male protrusion section of the coupling a recessed tension bolt 31 is then inserted into the threaded tension bolt hole.