Automatic sprinkler protection is recommended for industrial and other buildings having combustible construction or combustible occupancies. There are many types of automatic sprinklers. Typical examples include: upright, pendent, flush, recessed, concealed, sidewall, dry-pendent, dry-upright, extended coverage, corrosion resistant, and rack storage. A sprinkler operates automatically when the heat-actuated element is heated to, or above, its thermal rating. Selection of the proper temperature rating for automatic sprinklers is important. The proper rating provides a factor of safety designed to prevent premature operation.