Check the "O" ring seals before connecting gas cartridge to the appliance.
Align cartridge collar notch with locator tab on the Brazing torch and push down the troch to the cartridge until the locator to the cartridge .
Change or reconnect the gas cartridge outside and away form other people.
Be sure to cheek that no gas is leaking. If there is a gas leak on the appliance (smell of gas ), take it jkoutside immediately into a well ventilated, flame free location where the leaks may be detected and stopped. If you wish to check for leaks on your appliance, do it outside. Do not try to detect leaks with a flame,use soapy water.