A sprinkler head having a nozzle which is normally closed, but opens when exposed to a predetermined quantity of heat either by the melting of a fusible element or by the rupturing of a liquid-filled glass bulb.
A sprinkler head having a nozzle which is normally closed, but opens when exposed to a predetermined quantity of heat either by the melting of a fusible element or by the rupturing of a liquid-filled glass bulb.