... , Chrome Plating 3. 1/2" , 3/4" for dry hydrant system 4. wall side, pendent, upright open orifice sprinklers for dry ... hydrant system A fire sprinkler is the part of a fire sprinkler ... are based, with the heat sensitive operating element removed.Product name: open orifice sprinklers , orifice sprinklers , sprinkler heads for automatic fire ...