Greetings,
 
Since I'm now planning to use two evap cores
(ordered them today) in the
cheeks, and both DC EWP's, I'm trying to figure out
the best way to plumb
them.  First, this does mean that I'll get rid of
the mechanical pump, and
probably the pump housing as well.  In fact, I
ordered one of the Meziere
adapters for the block to make the plumbing easier.  
The adapter block has one large threaded hole for
water out to the
radiators, and two smaller threaded holes for water
in.  I don't really know
the size of the threaded holes yet, but I'm hoping
they're 3/4" NPT for the
smaller ones, and 1" NPT for the larger.   I'm
planning to order two one way
valves from McMaster Carr, as soon as I verify the
size of the holes.   Here's the current (never final) plan.  The large
outlet from the Meziere
adapter will go to a Y, then to the top of each
core.  The bottom of the
cores (other tank of course) will go to the pumps. The outlet of the pumps
will go back to the one way valves, which will be
screwed into the two inlet
holes in the Meziere adapter.   Here's the question of the day.  I could either run
each evap core to a
single pump, then to the engine, or I could combine
the outlets of the
cores, and run them to both pumps.  One way, a
single pump will only flow
through one core, where the other way, a single pump
will flow through both.
The second pump either adds a core to the circuit,
or doubles the flow to
both cores.  One core, at RV cruise speed is
probably all I need, and it may
be all I ever need in the winter.   Does anyone have
a feel for which would
be the better plumbing choice?   Thanks,
Rusty (hoping to "bring good things to light" in the
near future)