Unfortunately that fuel clogs up the filters. That is the entire problem.
Having clean fuel in the engine fuel system avoids the problem.

Doug

"jlp2550" wrote in message
...
Why not use the engine to do it - most diesels pump 3-4 times what
they use and return it. I have a selector valve on the return to
select which tank I want it back in.


On Tue, 25 Nov 2003 17:49:20 -0500, "Doug Dotson"
wrote:

I am designing a fuel polishing and transfer system. My thought
is to use valves to route fuel from any tank to any tank. No
problem with that part. I want to be able to just transfer fuel
or switch in a filter to polish the fuel while transferring. Since
I can select the same tank for source and destination, I can
polish fuel in place as well. The problem comes with the selection
of a pump. I was looking at a Groco or Jabsco pump which seems
good for transfer purposes, but way exceeds the flowrate of the
filter when polishing. A Walbro fuel pump (which I have as a priming
pump now) seems like a good fit for polishing (33 GPH) but will be slow
when just transferring fuel. What happens when a 5.5 GPM pump
(Jabsco) is pushing fuel through a filter rated at 60 GPH (RACOR 500)?

Thanks!
Doug
s/v Callista

Subject: Fuel transfer/polishing pump
From: "Doug Dotson"

Unfortunately that fuel clogs up the filters. That is the entire problem.
Having clean fuel in the engine fuel system avoids the problem.


Just go up a size or two in your filters. The surface area difference between a
500 Racor and a 900 Racor is tremendous.
Many times on a boat with filter clogging problems, I have just installed a
larger filter system and the time between changes has gone back to normal with
no more clogging in heavy seas problems.

Capt. Bill

Makes sense, but there is quite alot of evidence out there that
a polishing system is a good thing to have. I can't really
increase the size of my on-engine filter. I could increase the
size of the Raycor, but at the pore sizes I run (30 micron) in it make it
necessary to change the on-engine filter regularly as well.
Bigger Raycor won't fix the problem.

Doug

"LaBomba182" wrote in message
...
Subject: Fuel transfer/polishing pump
From: "Doug Dotson"

Unfortunately that fuel clogs up the filters. That is the entire problem.
Having clean fuel in the engine fuel system avoids the problem.


Just go up a size or two in your filters. The surface area difference
between a
500 Racor and a 900 Racor is tremendous.
Many times on a boat with filter clogging problems, I have just installed
a
larger filter system and the time between changes has gone back to normal
with
no more clogging in heavy seas problems.

Capt. Bill

"Doug Dotson" wrote in message ...
Makes sense, but there is quite alot of evidence out there that
a polishing system is a good thing to have. I can't really
increase the size of my on-engine filter. I could increase the
size of the Raycor, but at the pore sizes I run (30 micron) in it make it
necessary to change the on-engine filter regularly as well.
Bigger Raycor won't fix the problem.

Doug

"LaBomba182" wrote in message



Just go up a size or two in your filters. The surface area difference
between a
500 Racor and a 900 Racor is tremendous.

Actually the larger surface area of the element of the 900 or 1000
might help;

My theory was independent polisher with small pore size (Racor) but
RichH (who has not contributed to this thread) on polishing explained
it this way:

Complete Thread (26 articles)
Original Format
Newsgroups: rec.boats.cruising
Date: 2003-09-17 07:33:31 PST

RichH wrote:
If your polishing system is 'off line' ... not a part of the normal
fuel
distribution and return loop the following will exponentially improve
the retention ability and 'speed of recovery' if you happen to get a
load a cruddy fuel or the sea state breaks a slug of particale loose
from the tank walls, etc.:

Dont use 2uM filters in the loop! .... increase the nominal retention
rating to 10 or 15uM and the resultant final particle distribution *in
the tank* will be essentially zero and accomplish this level FASTER.
....
here's why:
Fibrous media filters have retention capability at essentially ALL
particle size levels. A 15uM fuel filter will remove approx 85 to 95%
of
of 15uM particles in a one single pass of the fluid through it, at
10uM
50%, at 5uM perhaps 30%, at 2uM maybe 15%. A 15uM filter will have
approx 4 to 5 times the flow rate capacity (gallons per minute per
psid)
of a 2uM filter ... meaning that the 15uM filter will cause less work
for the pump and overall flow will be FASTER. A 2uM filter will
deposit
2uM particles primarily on the surface of the media, a larger
retention
media will capture 2uM particles down deep in the media (for *more*
capacity of small particles) Since a polishing system is a closed
recirculation system you are constantly filtering the same fluid over
and over and over, each time the fluid passes through the filter it
leaves a few percent of smaller particles behind in the filter, since
a
larger retention filter has better flow characteristics the pump will
push through MORE fluid per minute and have less amperage draw. When
using a 2uM filter, the fluid returned during recirculation to the
tank
is again mixed with particle/debris laden fluid. A larger retention
filter will do the same job, to the same level of particles in the
tank
..... and do it faster because the larger retention filter has less
resistance to flow. With less resistance to flow a larger retention
filter will have less probability of extruding and releasing
SOFT/DEFORMABLE particles at it approaches differential pressures that
would 'clog' a filter.
Another benefit - If for example you have a crud contamination hanging
on the walls of the tank and the sea state causes the attached
particles/crud to break free and enter the fluid, the larger retention
filter (because of its less resistance to flow) will recover the tank
back to an acceptable particle distribution (particle recovery)
FASTER
than a smaller retention filter. Same story when taking onboard a load
of fuel that is contaminated.

Recirculation filtration is exponentially faster, more efficient, and
vastly more cost effective than single pass filtration. Use the
largest
filter retention possible (~10-20uM) to effect the fastest tank
turn-over... the tank will after a few turn-overs be to the same level
of residence particles. For the mathematicians, what is happening is
an
exponential decay of resident particles *in the tank*; since the
larger
retention filter (even with less efficiency with respect to the
'target
retention') is Faster because the exponential decay 'in the tank' is
faster. If you have time to burn, take ANY filter (includes compressed
pubic hair), recirculate for looooong times and you will have
essentially ZERO particles in the tank. Typically in industry a
recirc.
filter is sized about 5 to 10 times the size of the target residual
retention.


hope this helps. (RichH)

---


Captkeywest wrote:


no bs at all...

my permanently installed independent polishing system draws about 5
gallons (100 gallon tank) every 6.5 minutes through a racor 1000 with
2 micron (can switch to racor 900 when 1000's vacuum increases)

the engine has a racor 500 with 10 micron , then racor 500 with 2
micron, then the perkins 4-108 engine mounted filter.
as rich points out the 1000 elements aren't much more expensive than
the 500 elements, don't let the 500/1000 designations throw you, the
surface area of the 1000 is MUCH greater than twice the surface area
of the 500......

source:

http://groups.google.com/groups?hl=e...4%40NOSPAM.net

This helps alot, thanks! LaBomba suggested that just amking
the primary filter bigger would solve the problem. I was thinking
that this might be a easier solution, but it appears that a separate
polishing system does have advantages over just using a filter
that does not clog up so quickly. My intended strategy is to oly
fill one tank at a time, set the newly filled tank to polishing while
running the engine off of the other tank. Then when the engine
tank gets low, switch the engine to the polished tank, then
fill and polish the other tank. That way I always have clean
fuel ready and waiting (and plenty of it) and I don;t have to rush
to fill again.

I'm still in a quandry about Raycor style filters vs the paper towel
roll type. Perhaps RichH will chime in on this one since he is an
expert on filtration systems. Does Safeway carry 15 uM paper towels?

Doug
s/v Callista

"Roy G. Biv" wrote in message
om...
"Doug Dotson" wrote in message
...
Makes sense, but there is quite alot of evidence out there that
a polishing system is a good thing to have. I can't really
increase the size of my on-engine filter. I could increase the
size of the Raycor, but at the pore sizes I run (30 micron) in it make
it
necessary to change the on-engine filter regularly as well.
Bigger Raycor won't fix the problem.

Doug

"LaBomba182" wrote in message



Just go up a size or two in your filters. The surface area difference
between a
500 Racor and a 900 Racor is tremendous.

Actually the larger surface area of the element of the 900 or 1000
might help;

My theory was independent polisher with small pore size (Racor) but
RichH (who has not contributed to this thread) on polishing explained
it this way:

Complete Thread (26 articles)
Original Format
Newsgroups: rec.boats.cruising
Date: 2003-09-17 07:33:31 PST

RichH wrote:
If your polishing system is 'off line' ... not a part of the normal
fuel
distribution and return loop the following will exponentially improve
the retention ability and 'speed of recovery' if you happen to get a
load a cruddy fuel or the sea state breaks a slug of particale loose
from the tank walls, etc.:

Dont use 2uM filters in the loop! .... increase the nominal retention
rating to 10 or 15uM and the resultant final particle distribution *in
the tank* will be essentially zero and accomplish this level FASTER.
...
here's why:
Fibrous media filters have retention capability at essentially ALL
particle size levels. A 15uM fuel filter will remove approx 85 to 95%
of
of 15uM particles in a one single pass of the fluid through it, at
10uM
50%, at 5uM perhaps 30%, at 2uM maybe 15%. A 15uM filter will have
approx 4 to 5 times the flow rate capacity (gallons per minute per
psid)
of a 2uM filter ... meaning that the 15uM filter will cause less work
for the pump and overall flow will be FASTER. A 2uM filter will
deposit
2uM particles primarily on the surface of the media, a larger
retention
media will capture 2uM particles down deep in the media (for *more*
capacity of small particles) Since a polishing system is a closed
recirculation system you are constantly filtering the same fluid over
and over and over, each time the fluid passes through the filter it
leaves a few percent of smaller particles behind in the filter, since
a
larger retention filter has better flow characteristics the pump will
push through MORE fluid per minute and have less amperage draw. When
using a 2uM filter, the fluid returned during recirculation to the
tank
is again mixed with particle/debris laden fluid. A larger retention
filter will do the same job, to the same level of particles in the
tank
.... and do it faster because the larger retention filter has less
resistance to flow. With less resistance to flow a larger retention
filter will have less probability of extruding and releasing
SOFT/DEFORMABLE particles at it approaches differential pressures that
would 'clog' a filter.
Another benefit - If for example you have a crud contamination hanging
on the walls of the tank and the sea state causes the attached
particles/crud to break free and enter the fluid, the larger retention
filter (because of its less resistance to flow) will recover the tank
back to an acceptable particle distribution (particle recovery)
FASTER
than a smaller retention filter. Same story when taking onboard a load
of fuel that is contaminated.

Recirculation filtration is exponentially faster, more efficient, and
vastly more cost effective than single pass filtration. Use the
largest
filter retention possible (~10-20uM) to effect the fastest tank
turn-over... the tank will after a few turn-overs be to the same level
of residence particles. For the mathematicians, what is happening is
an
exponential decay of resident particles *in the tank*; since the
larger
retention filter (even with less efficiency with respect to the
'target
retention') is Faster because the exponential decay 'in the tank' is
faster. If you have time to burn, take ANY filter (includes compressed
pubic hair), recirculate for looooong times and you will have
essentially ZERO particles in the tank. Typically in industry a
recirc.
filter is sized about 5 to 10 times the size of the target residual
retention.


hope this helps. (RichH)

---


Captkeywest wrote:


no bs at all...

my permanently installed independent polishing system draws about 5
gallons (100 gallon tank) every 6.5 minutes through a racor 1000 with
2 micron (can switch to racor 900 when 1000's vacuum increases)

the engine has a racor 500 with 10 micron , then racor 500 with 2
micron, then the perkins 4-108 engine mounted filter.
as rich points out the 1000 elements aren't much more expensive than
the 500 elements, don't let the 500/1000 designations throw you, the
surface area of the 1000 is MUCH greater than twice the surface area
of the 500......

source:


http://groups.google.com/groups?hl=e...4%40NOSPAM.net

Doug Dotson wrote:

This helps alot, thanks! LaBomba suggested that just amking
the primary filter bigger would solve the problem. I was thinking
that this might be a easier solution, but it appears that a separate
polishing system does have advantages over just using a filter
that does not clog up so quickly.

There is a finite amount of filter-clogging gunk in your fuel system at any given time,
the more of it gets in your filter, the less stays in the system (and potentially ends up
in the injector pump & injectors). A filter element that does not clog up as quickly is
either 1- bigger and can thus hold more gunk OR 2- is letting a lot of the gunk pass
thru. QED


My intended strategy is to oly
fill one tank at a time, set the newly filled tank to polishing while
running the engine off of the other tank. Then when the engine
tank gets low, switch the engine to the polished tank, then
fill and polish the other tank. That way I always have clean
fuel ready and waiting (and plenty of it) and I don;t have to rush
to fill again.

Sounds good but it might take a while.



I'm still in a quandry about Raycor style filters vs the paper towel
roll type. Perhaps RichH will chime in on this one since he is an
expert on filtration systems. Does Safeway carry 15 uM paper towels?

At Trawlersfest I had two lengthy discussions with paper towel filter advocates. Their
theory is that the random oriented strands of the paper towel can trap any size particle,
down to sub-micron, instead of acting like a sieve to pass through anything below a given
size (they like to avoid mentioning that the "sieve" stops anything above it's rated
size). However they never explained why the filters don't clog up if they are indeed
trapping particles, or why particles can't become dislodged and re-enter the system.
Also, the paper towel systems they were advocating were all "bypass" filters, ie on the
pressure regulator discharge rather than on the main loop, so they did not filter more
than a small percentage of the fuel being pumped. This is due to the fact that paper
towels can't withstand a very high differential pressure.

Fresh Breezes- Doug King

"DSK" wrote in message
...
Doug Dotson wrote:

This helps alot, thanks! LaBomba suggested that just amking
the primary filter bigger would solve the problem. I was thinking
that this might be a easier solution, but it appears that a separate
polishing system does have advantages over just using a filter
that does not clog up so quickly.

There is a finite amount of filter-clogging gunk in your fuel system at
any given time,
the more of it gets in your filter, the less stays in the system (and
potentially ends up
in the injector pump & injectors). A filter element that does not clog up
as quickly is
either 1- bigger and can thus hold more gunk OR 2- is letting a lot of the
gunk pass
thru. QED

The filter on the engine seems to prevent ,ost remaining gunk from reaching
the injector pump and injectors. It must since it seems to be the one that
was clogging up most.

My intended strategy is to oly
fill one tank at a time, set the newly filled tank to polishing while
running the engine off of the other tank. Then when the engine
tank gets low, switch the engine to the polished tank, then
fill and polish the other tank. That way I always have clean
fuel ready and waiting (and plenty of it) and I don;t have to rush
to fill again.

Sounds good but it might take a while.

Take a while to what? Polish the tank?



I'm still in a quandry about Raycor style filters vs the paper towel
roll type. Perhaps RichH will chime in on this one since he is an
expert on filtration systems. Does Safeway carry 15 uM paper towels?

At Trawlersfest I had two lengthy discussions with paper towel filter
advocates. Their
theory is that the random oriented strands of the paper towel can trap any
size particle,
down to sub-micron, instead of acting like a sieve to pass through
anything below a given
size (they like to avoid mentioning that the "sieve" stops anything above
it's rated
size). However they never explained why the filters don't clog up if they
are indeed
trapping particles, or why particles can't become dislodged and re-enter
the system.
Also, the paper towel systems they were advocating were all "bypass"
filters, ie on the
pressure regulator discharge rather than on the main loop, so they did not
filter more
than a small percentage of the fuel being pumped. This is due to the fact
that paper
towels can't withstand a very high differential pressure.

According to RichH, the rated size of a filter is based upon what size
particles
it can remove on a single pass. A polishing system recirculates and each
pass
through the filter removes more because a filter is much more than just a
fancy
sieve. I dunno.

Fresh Breezes- Doug King

"DSK" wrote in message
...
Doug Dotson wrote:

This helps alot, thanks! LaBomba suggested that just amking
the primary filter bigger would solve the problem. I was thinking
that this might be a easier solution, but it appears that a separate
polishing system does have advantages over just using a filter
that does not clog up so quickly.

There is a finite amount of filter-clogging gunk in your fuel system at
any given time,
the more of it gets in your filter, the less stays in the system (and
potentially ends up
in the injector pump & injectors). A filter element that does not clog up
as quickly is
either 1- bigger and can thus hold more gunk OR 2- is letting a lot of the
gunk pass
thru. QED

The filter on the engine seems to prevent ,ost remaining gunk from reaching
the injector pump and injectors. It must since it seems to be the one that
was clogging up most.

My intended strategy is to oly
fill one tank at a time, set the newly filled tank to polishing while
running the engine off of the other tank. Then when the engine
tank gets low, switch the engine to the polished tank, then
fill and polish the other tank. That way I always have clean
fuel ready and waiting (and plenty of it) and I don;t have to rush
to fill again.

Sounds good but it might take a while.

Take a while to what? Polish the tank?



I'm still in a quandry about Raycor style filters vs the paper towel
roll type. Perhaps RichH will chime in on this one since he is an
expert on filtration systems. Does Safeway carry 15 uM paper towels?

At Trawlersfest I had two lengthy discussions with paper towel filter
advocates. Their
theory is that the random oriented strands of the paper towel can trap any
size particle,
down to sub-micron, instead of acting like a sieve to pass through
anything below a given
size (they like to avoid mentioning that the "sieve" stops anything above
it's rated
size). However they never explained why the filters don't clog up if they
are indeed
trapping particles, or why particles can't become dislodged and re-enter
the system.
Also, the paper towel systems they were advocating were all "bypass"
filters, ie on the
pressure regulator discharge rather than on the main loop, so they did not
filter more
than a small percentage of the fuel being pumped. This is due to the fact
that paper
towels can't withstand a very high differential pressure.

According to RichH, the rated size of a filter is based upon what size
particles
it can remove on a single pass. A polishing system recirculates and each
pass
through the filter removes more because a filter is much more than just a
fancy
sieve. I dunno.

Fresh Breezes- Doug King

At Trawlersfest I had two lengthy discussions with paper towel filter
advocates. Their
theory is that the random oriented strands of the paper towel can trap any
size particle,
down to sub-micron, instead of acting like a sieve to pass through anything
below a given
size (they like to avoid mentioning that the "sieve" stops anything above
it's rated
size).
Next time you get into this type of discussion, ask them how the fibers
are held together so that they dont release particles under increasing
differential pressure. You need a resin to hold the fibers together.
Then ask them how much particulate bypasses the 'knife edge' seal that
'bites' into the end of the paper roll.
Then get a glass of water, crumple up some of their paper roll, put it
into the glass of water. Wait to see how long the paper takes to
disintegrate into a slurry. Tell me where on this planet that there
is NO water in fuel oil, either as free water or as an emulsion.
;-)

At Trawlersfest I had two lengthy discussions with paper towel filter
advocates. Their
theory is that the random oriented strands of the paper towel can trap any
size particle,
down to sub-micron, instead of acting like a sieve to pass through anything
below a given
size (they like to avoid mentioning that the "sieve" stops anything above
it's rated
size).
Next time you get into this type of discussion, ask them how the fibers
are held together so that they dont release particles under increasing
differential pressure. You need a resin to hold the fibers together.
Then ask them how much particulate bypasses the 'knife edge' seal that
'bites' into the end of the paper roll.
Then get a glass of water, crumple up some of their paper roll, put it
into the glass of water. Wait to see how long the paper takes to
disintegrate into a slurry. Tell me where on this planet that there
is NO water in fuel oil, either as free water or as an emulsion.
;-)