Vacuum relief plumbing fitting
FIG. 1 is a left side elevational view of a vacuum relief plumbing fitting showing our new design, the right side being a mirror image of the left side; 
     FIG. 2 is a front elevational view thereof; 
     FIG. 3 is a rear elevational view thereof; 
     FIG. 4 is a top plan view thereof; and, 
     FIG. 5 is a bottom plan view thereof.