I think this is what I said. Too small a filter (pore size) causes
stress on the lift pump. This is what the mechanic said and also
what the memo from Yanmar stated. A clogged filter will always
place stress on the pump. The case was told of was using a 2u
filter in a Raycor 500. I'm installing a permanent
polishing system as well.

Doug

"RichH" wrote in message
...
Sorry but these 'mechanics' have it all and entirely WRONG !!!!!

Too small a filter means NOT too small a retention rating but too small
a SURFACE AREA of the filter. What kills the lift (or any other) pump is
particulate and continually working against a high differential pressure
caused by either too small or too plugged a filter.

If you have a dirty tank or a tank without a recirculation filter use:
30uM followed by 10uM followed by 2uM ... the 2uM can be the 'guard'
filter between lift and high pressure pumps.

If you double the surface area, the differential pressure needed to
operate the filter at the design flow will be HALF .... and the service
life (to plugging) will be approximately *FOUR* times longer; plus, the
particles will be stopped on the filter media! The higher the
differential pressure the greater the possibility to extrude soft and
deformable particulate through the filter media.... only to plug a finer
rated filter / orfice, etc. downstream.

Of course you MUST in all cases monitor the performance of such filters
with pressure/vacuum gauges ... and check them periodically to develop a
plot of lifetime vs. time/gallons in service and WHEN to change them.
Bigger filters will SAVE you $$$$ and 'sudden' headaches, are more cost
effective and "removal efficient" than changing out teeny (and just as
expensive) filters on a 'seasonal' basis. Change when the pressure
gauges tell you to change them, install at least the next LARGER
*surface area* filter recommended, ............ instead of waiting for
the filters to plug ... when the weather is very rough/severe, you NEED
the engine to keep moving for safety, you and your crew are
seasick/tired/terrorized/etc.... and on top of this you have to go below
and change the filters then bleed the system - all the while you're
projectile-puking great lumps into the smelly bilge. That's not my idea
of fun!

Better yet is to install a recirculation filter with an integral gravity
water knock-out pot ... then you only need a regularly sized final
filter, will have no bacteria/water/particulate/sudden power
loss/etc./etc./etc.
You can wire such a system so that the recirc. pump operates any time
the engine is operating.

Hope this helps.

If a 0.000000000002 micrometer rated filter has enough surface area it
will operate with LESS differential pressure than a small surface area
filter with 3 METERS pore size.

This is a vacuum pump ... meaning that it only has to deliver 15 psi
motive pressure plus about 2-3 feet of static head. A small dog can ****
harder than that.
The service advisory simply admits that Yanmar has a WEAK pump!!!!!!! A
pump that cant run against a 'dead-head'is cheap, ill designed, etc.

A clogged filter will always place stress on the pump. A filter begins
to become 'clogged' when approx 85% of its 'dirt capacity' is used, less
than that the pressure drop is linear, after that it rapidly accelerates
the rate of 'clogging' (becomes exponential) ..... thats why you NEED a
gauge to monitor it.

I'm installing a gauge as well, readable from the steering station. When
I owned the Yanmar, I chose to abide by what the manufacturer said
rather than risk my warranty. I'm funny like that. New system is going to
take into account all the good advise you and other have offered. I'm
not going to get caught with a dead engine again.

DOug

ps. Get a bigger dog

"RichH" wrote in message
...
If a 0.000000000002 micrometer rated filter has enough surface area it
will operate with LESS differential pressure than a small surface area
filter with 3 METERS pore size.

This is a vacuum pump ... meaning that it only has to deliver 15 psi
motive pressure plus about 2-3 feet of static head. A small dog can ****
harder than that.
The service advisory simply admits that Yanmar has a WEAK pump!!!!!!! A
pump that cant run against a 'dead-head'is cheap, ill designed, etc.

A clogged filter will always place stress on the pump. A filter begins
to become 'clogged' when approx 85% of its 'dirt capacity' is used, less
than that the pressure drop is linear, after that it rapidly accelerates
the rate of 'clogging' (becomes exponential) ..... thats why you NEED a
gauge to monitor it.

Subject: New style (spin on) Raycor (diesel) fuel filters
From: "Doug Dotson"

I'm installing a gauge as well, readable from the steering station. When
I owned the Yanmar, I chose to abide by what the manufacturer said
rather than risk my warranty. I'm funny like that. New system is going to
take into account all the good advise you and other have offered. I'm
not going to get caught with a dead engine again.

If you're going to all that trouble you might as well install the water probes
and alarms while you're at it.

Capt. bill

Good idea.

"LaBomba182" wrote in message
...
Subject: New style (spin on) Raycor (diesel) fuel filters
From: "Doug Dotson"

I'm installing a gauge as well, readable from the steering station. When
I owned the Yanmar, I chose to abide by what the manufacturer said
rather than risk my warranty. I'm funny like that. New system is going to
take into account all the good advise you and other have offered. I'm
not going to get caught with a dead engine again.

If you're going to all that trouble you might as well install the water
probes
and alarms while you're at it.

Capt. bill

Uhmmm....

RichH wrote:

If a 0.000000000002 micrometer rated filter has enough surface area it
will operate with LESS differential pressure than a small surface area
filter with 3 METERS pore size.

Hardly! You need to study the issue of "bubble point" before making this
type of assertion. Basically, surface tension becomes the dominant
factor in backpressure when porosity is decreased to sub-micron levels.
In GENERAL, one can overcome delta-p issues due to lower average
porosity by increasing surface area, but certainly not allways.

Oh, and "small surface area" and "3 METERS" together do not make a
filter. It's a "HOLE". A BIG hole :-)

Keith Hughes

Here's my experience with vacuum gages. I have a Lehman 135. The primary
filter is a Racor 900 with 2 micron filters. The final is now a Racor
Spin-on with a 2 micron cartridge. I always check the vacuum gage on the
Racor underway, and it NEVER shows any vacuum. I even let that filter go too
long and pulled it out looking like it was coated with black jelly... still
no vacuum or effect on the engine. The filter is just HUGE compared to what
the Lehman sips... about 4 gallons/hr. consumed, 1.5 GPH or so returned. I
even took the vacuum gage off awhile back to make sure it was working; it
was fine.

If you have a filter that's really big compared to what your engine uses,
you'll almost never show any vacuum.

--


Keith
__
It's only unethical if you get caught.
"Doug Dotson" wrote in message
...
I'm installing a gauge as well, readable from the steering station. When
I owned the Yanmar, I chose to abide by what the manufacturer said
rather than risk my warranty. I'm funny like that. New system is going to
take into account all the good advise you and other have offered. I'm
not going to get caught with a dead engine again.

DOug

ps. Get a bigger dog

"RichH" wrote in message
...
If a 0.000000000002 micrometer rated filter has enough surface area it
will operate with LESS differential pressure than a small surface area
filter with 3 METERS pore size.

This is a vacuum pump ... meaning that it only has to deliver 15 psi
motive pressure plus about 2-3 feet of static head. A small dog can ****
harder than that.
The service advisory simply admits that Yanmar has a WEAK pump!!!!!!! A
pump that cant run against a 'dead-head'is cheap, ill designed, etc.

A clogged filter will always place stress on the pump. A filter begins
to become 'clogged' when approx 85% of its 'dirt capacity' is used, less
than that the pressure drop is linear, after that it rapidly accelerates
the rate of 'clogging' (becomes exponential) ..... thats why you NEED a
gauge to monitor it.

ummmmmmm yourself

Bubble point is related to retention efficiency ---- ONLY.

If your were filtering a 60/40 mixture of isopropyl alcohol and water
your statement would have (some) validity .... but ONLY if your were
using uniform porosity polymeric *membranes* at retention levels below
0,45uM. It is a mathematical/physical impossibility to consider 'bubble
point' for such fixed media (fiberous) and comparatively HUGE retention
sizes. If you know what a bubble pointg is, then you also know that such
fixed fibrous media has inconsistant porosity and permeability - ie. a
2uM media will have 'pores' approaching 50 or 100uM!!! Bubble point is
simply not applicable.
For yourself I respectfully suggest that you look up the filtration
regimes as defined by the ASTM "OSU F-1 protocols"

Operating differential pressure is SOLEY due to the absolute viscosity
of the fluid!!!!

Bubble point is a nondestructive CORELATION or a bacterial (specified
test organism) challenge (or latex spheres) ... to a plugging situation
using specific test organisms on MEMBRAWES. Oil filters use a fiberous
media ... where bubble point is totally nonapplicable: 1. non uniform
media, 2. retention matrix larger than 1uM. Tell me where on this
planet that one can do a 'bubble point' (or forward flow diffusion) on
the media type used in fuel oil filters? - is fiberous and non-uniform
in permeability; and thus, are unable to be tested via bubble point as
the contact wetting angle of surface tension vs. the media is
nonuniform. Bubble point is ONLY perfomed on MEMBRANES of ?0.45uM used
in filtration .... not on fiberous nonuniform porosity media.

Differential pressue of a CLEAN filter is SOLELY due to the absolute
viscosity (viscous shear) of the fluid being filtered. Surface tension
is irrelevent with respect to viscous shear/?P. Changing the surface
tension (wetting angles) will ONLY affect the *retention* ability under
varying intrusion pressures ... ie:. modifying the van der walls
absorbtive attraction at the BET surface of the media or membrane.
Differential pressure affects the internal velocity of the fluid THROUGH
filter media/membrane AND those media with high ?P will have/approach
insufficient contact or residence time for absorbtion mechanism of
capture; thus, leaving only mechanical means of 'captu'seiving',
direct interception and inertial impaction. You can matematically
predict by the (area1/area2)E1.66 = (velocity2/velocity1)E1.66 =
((Q/deltaP1)/(Q/deltaP2))E1.66 ...as a LIFE performance predictor (the
exponential varies between 1 for high viscosity non-newtonian fludis to
approx 1.666 for newtonian fluids.... no surface tension/wetting angles
involved.

sorry, the greek delta was ASCII transmitted as a: ?
therefore the "?P" characters in the previous posting should be read as
"delta P"

jscanlon wrote in message


--
Always use the filter type the manufactorer reccomends. Polishing (BS
in my opinion)


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......