The Firesafe Cannula Valve is essentially a thermal fuse, comprising a spring loaded valve held open by a T-bar. The T-bar is situated downstream of the valve and supported by a fusible ledge of material. The Firesafe valve is actuated when the fuisble ledge softens as a result of heat from an approaching fire in the oxygen delivery tubing. Upon actuation the valve probe moves forward and an o-ring seals the valve, thereby isolating the oxygen supply from the fire.
It is recommended that at least two Firesafe devices are fitted to each oxygen delivery circuit. The first, either a Firesafe Nozzle or Firesafe Cannula Valve depending on your oxygen setup, should be positioned close to the source of supply; and the second, a Firesafe Cannula Valve, should be positioned close to the patient. The Firesafe Cannula Valve provides no protection if a fire burns through the oxygen delivery tubing upstream of the device.