Issue A and B Window Type Sprinklers

Issue A and B exposure-protection sprinklers are used to spray water on window glazing at set intervals. This helps protect against exposure fires on the exterior of the building. The Issue A sprinklers have a smaller orifice compared to Issue B sprinklers. Issue A is normally used where exposure is light or moderate, the area of coverage is small, or where one horizontal line of window sprinklers is installed at each floor. The larger orifice Issue B sprinklers are normally used where exposure is severe or where one horizontal line of sprinklers is used to protect windows at more than one floor level.