Dielectric Nipples are common in the case of metal nipples, which is used were dissimilar metals occur in piping and plumbing systems. In metal nipples the rust will build up around the nipples entering the cast iron threaded or the steel coming from the other fittings, which will result in galvanic corrosion. Galvanic corrosion will happen when there is a connection between two dissimilar metals without the use of dielectric fittings. Metals have potential and each type of metal has a different potential. When you make a connection between two or more dissimilar metals using a usual metal nipple you create a potential difference, which makes one metal fitting to corrode and resulting in problem, so to solve this problem dielectric nipples will be used, which will redistribute the charge within its atoms or molecules. This redistribution can alter the shape of an electrical field both inside the dielectric medium and in the region nearby.