The Gruvlok Fig. 7091 DI-LOK Fitting prevents the formation of a galvanic cell between grooved end steel pipe and copper tube. The separation of copper from steel by the fitting virtually eliminates the galvanic cell created by the dissimilar metals. The DI-LOK Fitting is designed for use at temperatures from -40˚F to 230˚F (-40˚C to 110˚C) and pressures to 300 psig (20.7 bar) in a wide range of applications.