Nitech Stainless Inc is among the best  Stainless Steel Slip On Flanges Manufacturer in India. A Stainless Steel Slip-On Flange is a flange that fits over the end of a pipe and is welded in place. It has a slightly larger internal diameter than the pipe’s exterior diameter, allowing it to move over and position itself when welding. The flange is then welded inside and out to provide the necessary strength and prevent leaks.