On a conventional FI engine, are there any benefits to plumbing the boost pump in parallel to the engine driven pump? The way I see it, putting it in parallel, makes the system more complex because of additional tubing, connections, check valves, possibly additional firewall penetration. Can the engine driven pump fail in such a way as to cut off the fuel flow? If not, then I don't see a reason to consider plumbing the boost pump in parallel. What am I missing?
I've tried to research the issue and came back empty handed as far as airplanes are concerned. As far as fuel and other liquids outside of aviation are concerned, plumbing pumps in parallel is done to increase the flow rate, in series -- to increase head pressure. Neither is needed or desired in our application -- either the engine driven or the boost pump must provide sufficient pressure and flow in any case.
I've tried to research the issue and came back empty handed as far as airplanes are concerned. As far as fuel and other liquids outside of aviation are concerned, plumbing pumps in parallel is done to increase the flow rate, in series -- to increase head pressure. Neither is needed or desired in our application -- either the engine driven or the boost pump must provide sufficient pressure and flow in any case.