The Pen-Seal Calculator is a useful tool to help aid in the proper selection and installation of pipe penetration seals (Pen-Seals) into a piping system. This calculator is designed to assist in selecting the correct number of links and the correct size of link for pipe penetrations passing through walls or floors. To achieve a 100% water or gas tight seal, enter in the pipe O.D. and the penetration I.D. to provide the required size/link combination.