Frank Wall RSP18 Rigid Suction Pipe for 18″ Sun Ledge - This Rigid Suction Pipe is for pulling the vinyl liner tight. We have made this rigid suction pipe for an 18" sun ledge. This is a 3 chamber rectangle vacuum tube with more suction holes on the sides. This helps to prevent the liner from sucking tight around the tube and shutting off air flow. We have made a recessed neck to fit over the coping which allows the tube to sit flush against the pool wall. We have made a stronger flexible connection hose to connect the suction pipe to the liner vacuum