Could someone please help clarify what exactly is meant by "dual refill lines" in the following section of the NFPA 22:
14.5 Break Tanks....
14.5.3 Refill Mechanism. The refill mechanism shall be listed and arranged for automatic operation.
18.104.22.168.1 Dual automatic refill lines, each capable of refilling the tank at a minimum rate of 150 percent of the fire pump(s) capacity, shall be installed.
Would that imply that two separate water services are required, or just two separate automatic refill mechanisms which could theoretically be connected to the same header?
Thank's in advance.