Gruvlok fittings are available through 24" nominal pipe size in a variety of styles. Use the Fitting Size Table to convert nominal pipe size to corresponding pipe O.D. These fittings are designed to provide minimum pressure drop and uniform strength. Depending on styles and size, Gruvlok fittings are provided in various materials including ductile iron, forged steel or fabricated steel. Pressure ratings of Gruvlok standard fittings conform to those of Fig. 7001 Gruvlok coupling.