The outlet is typically placed towards the bottom of the tank, where, as the tanks fills, the greatest pressure is exerted. Brass fittings for the outlet pipe/valve have proven to be the major contributor to a problem commonly known as fitting split. Continual pressure on the foreign material drilled into the tank can cause a small split to occur, above or below the brass fitting, spreading as the fluid escapes. To eliminate fitting split Nu-Tank poly fuse the poly outlet to the entire thickness of the wall of our larger tanks, then weld around the outlet. Watch video about Poly Fusing and Welding