108.443—Controls and valves.
        
        (a) 
         At least one control for operating a CO2 system must be outside the space or spaces that the system protects and in a location that would be accessible if a fire occurred in any space that the system protects. Control valves must not be located in a protected space unless the CO2 cylinders are also in the protected space.
    
    
        
        (b) 
         A CO2 system that protects more than one space must have a manifold with a stop valve, the normal position of which is closed, that directs the flow of CO2 to each protected space.
    
    
        
        (c) 
         A CO2 system that protects only one space must have a stop valve installed between the cylinders and the discharge outlets in the system, except on a system that has a CO2 supply of 136 kilograms (300 pounds) or less.
    
    
        
        (d) 
         At least one of the control stations in a CO2 system that protects a machinery space must be as near as  practicable to one of the main escapes from that space.
    
    
    
        
        (f) 
         Each CO2 system that has a stop valve must have a remote control that operates only the stop valve and must have a separate remote control for releasing the required amount of CO2 into the space protected by the system.
    
    
        
        (g) 
         Each CO2 system that does not have a stop valve must be operated by a remote control that releases the required amount of CO2 into the space protected by the system.
    
    
    
        
        (i) 
         Each system must have a manual control at its cylinders for releasing CO2 from the cylinders, except that if the system has pilot cylinders, a manual control is not required for other than pilot cylinders.
    
    
        
        (j) 
         If gas pressure is used to release CO2 from a system having more than 2 cylinders, the system must have at least 2 pilot cylinders to release the CO2 from the remaining cylinders.
    
    
        
        (k) 
         If the entrance to a space containing the CO2 supply or controls of a CO2 system has a lock, the space must have a key to the lock in a break-glass type box that is next to and visible from the entrance.