Yes. A simplified example. The formula for pump horsepower is
(GPM*PSI)/1460 so moving 3GPM at 800PSI requires 1.64HP. Moving the same
3GPM at 50 PSI requires .1HP. 1 HP= 746 watts (62amps @12V) so the high
pressure pump will draw 100 amps and make 20 to 22 gallons of product an
hour for about 5 amp hours/gallon. The low pressure system draws 6 or 7
amps and might produce 7 or 8 gallons an hour for about 1 amp hour.gallon.

In reality friction and pump losses will make the ratios more like 6 or
7AH/gal and 1.2 to 1.5AH/gal but the Clark pump based systems are still far
more efficient and running a 1.5 to 2HP pump for an hour is really not
practical on a battery bank. You just have to choose between the extra $3K
for the Clark pump or $4K for a genset to run the high pressure pump.

That is why I chose $150 and some sweat equity for a belt drive off the
engine. :-)

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Skip Gundlach" wrote in message
oups.com...
So, is the clark pump the basis for a supposed increase in efficiency?
I'm not real fond of even the 1.4A/gallon Spectra claims, but then I
looked at others and saw 3-4x that number...

Working on very low pressure pumping, myself, at the moment...

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
http://tinyurl.com/p7rb4 - NOTE:new URL! The vessel as Tehamana, as we
bought her

"Believe me, my young friend, there is *nothing*-absolutely
nothing-half so
much worth doing as simply messing, messing-about-in-boats; messing
about in
boats-or *with* boats.
In or out of 'em, it doesn't matter. Nothing seems really to matter,
that's
the charm of it.
Whether you get away, or whether you don't; whether you arrive at your
destination or whether you reach somewhere else, or whether you never
get
anywhere at all, you're always busy, and you never do anything in
particular; and when you've done it there's always something else to
do, and
you can do it if you like, but you'd much better not."