According to NFPA 58, the minimum clearance for a relief valve to a source of ignition is 5 ft for an exchange cylinder, and 10 ft for a tank filled on site. It was always my understanding that if a cylinder that COULD be filled on site was swapped for an exchange cylinder, the 5 foot rule no longer applies and must be 10 ft. I really need an answer to this as management states it is okay to still be in compliance under 10 feet if the cylinder is filled off site. I don't trust them, and feel it will be a matter of time before a bulk driver will be asked to fill one. They are playing with words to bend the rules IMO.