All No. 1 and No. 2 fuel oil tanks from 11 to 5,000-gallon capacity located inside a structure must have a vent alarm.
All No. 1 and No. 2 fuel oil tanks from 65 to 5,000-gallon capacity located outside must have a vent alarm.
All vent alarms must be installed according to manufacturer's Instructions.
02-658 C.M.R. ch. 8, § 12