Viking Fire Sprinkler Guard for 12" & 34" Sprinkler Heads. The Viking Sprinkler Guard is a hard-wire cage designed to encase the sprinkler and protect it from mechanical daamage. It is recommended for areas where the sprinkler is installed at a low elevation andor near areas of high human or mechanical activity.The Model D-1 Sprinkler Guard is for use with Viking standard and large orifice, standard and quick response upright and pendent frame style sprinklers. Chromate over zinc plated steel.