"Kelton Joyner" wrote in message
.. .
Unless you have isolation valves to allow servicing of a parallel pump,
series works just as well for backup.
fuel wil flow through the unpowered pump.

Depends on the type of pump. A possitive displacement pump (roller, vane,
etc.) will block the flow from the other pump.. This isn't a problem with a
diaphram or centrifigal it would work, however would subject the idle pump
components to pressure or could be a source of leakage once it failed.

Steve
s/v Good Intentions