As a result of FM's directive, Underwriters Laboratories (UL) recently conducted its own full-scale fire testing of large drop sprinklers. These tests successfully demonstrated that the performance of Viking's large drop sprinklers is consistent with current UL listing criteria for these products. As such, Viking will continue to manufacture and distribute UL-listed Large Drop fire sprinklers.
Factory Mutual's analysis of all manufacturers' large drop sprinkler technology is ongoing.