N.D. Cent. Code § 18-12-22
A master valve must be provided in each room where there are three or more gas outlets. This valve must be conveniently located and easily distinguishable so that it may be readily closed when the room is not in use. If a room is not in use, the administrator's desk and the laboratory proper should be kept under lock and key.
A shutoff valve must be provided outside the building.
All gas heaters must be vented unless approved by the state fire marshal.
All liquefied petroleum gas, or bottled gas, installations must be in accordance with the state regulations for such use. When such gas supply lines are placed in tunnels, they must be without joints and the tunnels must have forced ventilation, except when the length of the line does not exceed the width of the tunnel ventilation does not have to be provided.
N.D.C.C. § 18-12-22