At Witt Lining Systems, we pride ourselves in providing the best fitting tank liners in the industry. One key to a great fitting liner is accurate dimensions of the area to be lined.
A common feature in welded tanks (steel or plastic) is a fillet weld. A fillet weld is the process in joining two pieces of material together, typically at a perpendicular angle. The weld is triangular and can have a flat, concave, or convex surface depending upon the technique used by the welder.
With regards to the quality of fit of a Witt drop in liner, the size of the fillet weld can influence the fit of the liner. Generally, if the face of the fillet weld is under ½ inch in size the weld will not affect the fit of the liner. Simply measure the inside dimension between tank walls. If the fillet weld is larger than that we may undersize the liner to account for the weld while allowing the elongation properties of the material to accommodate the offset in dimensions. If over 1 inch in size, then in most cases we will build that fillet weld in to the liner itself ensuring for a proper fit of the tank liner.
As expected, a liner will only fit as well as the dimensions given for fabrication and the size of the welds used needs to be considered. Also, inspect the welds for any burrs or sharp points that could possibly puncture the flexible liner. Remove any such areas prior to liner installation.