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Rich Hampel
 
Posts: n/a
Default Parallelling fuel pumps

Constant flow through the day tank; the fuel is retained by an inverted
"dip tube" outlet. Its arranged so that only when a "bypass" cock at
the bottom is opened does the tank empty.


In article , Doug Dotson
wrote:

Answers below.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Doug,
Do you have a sailboat or a trawler/stinkpot?


Sailboat.

If you have a sailboat, you can finally raise a sail, heave-to/anchor,
go below and brew some tea, or just go to sleep until the sea-state
calms down and you can sort out what's the problem - later.


Nice theory. A lee shore and shoals might make that approach a bit
risky though. Low winds and strong currents in close quarters also
makes such an approach a bit too exciting to be worth saving a
couple hunderd bucks over.

Thats why I advocate a small capacity gravity feed 'day tank' .... NO
bleed or lift pumps, NO filters, NO electricity .... just nature's
gravity to feed oil to the injector pump; single cock to switch it
online to the fuel system .... 2-1/2 to 3 gallons of clean
prefiltered fuel oil can take you a looooong way in an emergency.
KISS. ;-)

I agree, but as I said before, I have no practical space at a level
above the engine for a day tank. I suppose that in an emergency
I can set a jerry can in the pilot house and gravity feed it though.
Wish I had though of that a year ago when we lost our engine due
to a failed lift pump half way across the Gulf Stream

It seem that you reserve your day tank for emergencies only. What
prevents the prefiltered fuel from going stale and getting growth?





In article , Larry W4CSC
wrote:

"Doug Dotson" wrote in
:

Glenn,

That is pretty much what I was figuring on other than the
check valves. Not sure I want a center off switch though.
I would prefer that one or the other be on at all times. I'm
also considering putting an hours-meter on each so that I
can balance the use.

Doug
s/v Callista


I'll also vote for a manual valve on both in parallel......

We're in a seaway, big waves. The pump goes into failure mode, we

switch
on the backup and are back in business. Wouldn't it be good if we could
isolate the failed pump for repairs, remove/replace or tear it down for
that new diaphram while the other pump has the load and the first mate

or
autopilot is driving? Sure would be nice to be able to get that failed
pump offline while the boat's still underway for repairs. Can't do that

on
the series pumps without some crazy plumbing bypasses and lots of
valves....

Larry W4CSC