I am intrigued by the discussion - particularly the mental picture of 2
pumps in Series or Parallel. There seems a discrepancy in some of ther
discussions in the true meanings.
If it were truly Series, what plugs the first will plug the second pump, so
I conclude (from the electric alanogy) that the present setup is
Series-parallel of a kind.
If both filters come first and are in parallel, all parts downstream should
be clean. Because they are parallel, as one begins to block, the other takes
on the whole task - so regular inspection should satisfy any precautionary
need. But my pumproom is at the rear, so I figure I need a shutoff valve
upstream of the filters so I can open them. Then, filter 1 leads to check
valve 1 and filter 2 leads to Pump 1, they combine into one line and split
again (tee) one branch to check valve 2, and the second branch to Pump 2.
They recombine into one line (which in my case leads to a lowest Gascolator
and off to the engine .
Thus (if you sketch this out corrctly), the two pumps are clearly one after
the other (series), but if any component plugs, another will feed the fuel
through an alternate line (parallel). In any case, I'm hoping the flow
pressure is not excessive, either with all bits working, or when one branch
is plugged.
I also have the excess fuel returning under the starboard sill to
the fuel filler entry on the tank. Is there any foaming involved in the
overflow fuel? If there is I'm hoping it dissipates on top of both tanks
when fuel is above the saddle, and on top of reserve when sucking from the
bottom.
I realise I'm not designing for Mars, but hope I am on track to a secure
fuel transfer plot.
Flames and flowers eagerly anticipated.
Ferg
A064
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