I have in my house installed a water mist fire protection system. Currently it is connected directly to the main water system, which is of lower pressure than the nozzles are designed for.
I would like to add a pump and an expansion/pressure tank to increase the pressure.
My question is what kind of water pump can I use for this? It is an absolutely requirement that it will not significantly reduce the pressure or amount of water flowing through it in case of missing electricity. How well will centrifugal pumps let water flow through without power?
A battery backed solution that turns on/off a bypass path in case of power loss might be acceptable, but my initial thought is that this is added complexity and something that could fail so I think I would prefer not to have that.
Since the normal use case will be that the pump starts once to fill the tank and then never start again, power consumption and efficiency are of no relevance.