... .Automatic fire sprinklers utilizing frangible bulbs follow a standardized color coding convention indicating their operating ... . The time it takes before a bulb breaks is dependent on the temperature. Below the design temperature ... /s), a 68 °C sprinkler bulb will break within 7 to 33 seconds, depending on the RTI ... Of course, if a ceiling has been painted, and some paint gets on a bulb, it will not ...