A built-in fusible element in the latch release melt if exposed to fire allowing the operating lever to return to the closed position. (For the temperature 212°F / 100°C).
All Cavagna brand Internal Valves can be fitted with a manual latch/remote release mechanism. When the Internal valve’s operating lever is manually moved to the open position, the lever can be latched in the open position. The lever can be released from a remote location by pulling on the cable attached to a pull ring, thus closing the internal valve.