Hi, I am aware that oxy / acetelyne bottles have flashback arrestors but we use the mains gas (piped) into 2 pits for the purpose of pre-heating moulds. This pipework branches off into seperate feeds. Does anyone know if these feeds should be fitted with the fba - it is fed directly from the mains supply but my searches so far contradict each other - one local council highlights the need for fba's at strategic points while other web based info states "not required". Most paperwork discusses welding or cutting torches. thanks