10623 DIELECTIC NIPPLE 3/4X3/4 | The 2-1/2 in dielectric nipple is designed for use in water heater inlet and outlet hook-ups and for other uses where dissimilar metals occur in piping and plumbing systems. The thermoplastic lining helps prevent corrosion and the ends are 3/4 in NPT tapered pipe thread for a fluid-tight seal. Dielectric nipple measures 2-1/2 in Length and is sold in a convenient 2-pack.