This is a schematic of the water system in the house. The blue is what is there already. I have labeled the valves and such with orange numbers. Green is what I was thinking we could add to eventually insert a backup system.
Let me know your opinion. I would presume that we would tap into the system as it comes in and goes out after isolating the failed system with valves.
It seems that there are already some valves in place that could isolate the system. What is lacking is a place to tap into the input (from the cistern) and output (to the home). The existing system has a hose bib (1) that could be used connect to the backup system but the existing system would not be isolated. Thus I would think we would either need another ball valve in position 3 or we would need to add a tap above valve 1.
Likewise, on the system output, there is an isolating valve, 6, but no way to tap into the system. Thus I think that either a hose bib or a ‘T’ with ball valve as shown would allow us to tap into the system later on. This ‘T’ and valve could go further downstream near the ceiling or other wall.
A hose bib is not the best way to tap into a system but it is there already.
Scroll down for some photos of the system if you need to refer to that.
David Jackson 214.244.2912