Another good reason NOT to pull vacuum on fuels and other volitile
liquids is that if the vacuum exceeds the vapor pressure of the fluid
the liquid with boil (flash) or you will separate out the lighter
fractions (lighter weight hydrocarbons). If youve ever had a gasoline
that had 'vapor-lock' problems you'll understand this phenomenom. I
dont have by me at this time a listing of the vapor pressure range of
#2 diesel fuel but you must understand that #2 is a mix of various
fractions. From that standpoint alone and the potential of 'flashing
by vacuum application make vacuum a less conservative approach to fuel
delivery systems.

"Rick" wrote in message
k.net...
Rich Hampel wrote:

The use of a centrifuge on the small volume boat tankage .... borders
on ludicrous.

your opinion is not universal. Besides, we were writing
about FUEL POLISHING ... an activity normally performed
alongside a dock at rather extended intervals.

Actually, we are talking about permanently installed polishing systems
that run for extended periods of time. In general, they run the entire time
the engine iss running and also when the boat is sitting at anchor or at a
dock they run for several hours per week.

Centrifuges are extreme high maintenance rotating and
power consuming equipment

Just because you don't like them ... and you have a peculiar
vision of "extreme" maintenance.

Not practical for the type of system we are talking about here.

and do NOT effect total removal/separation of
emulsions. If you have enough power to run a centrifuge, then I
suggest that you rip out the fossil fuel engine and simply replace with
an electric motor for propulsion.

A rather extremist position. There are plenty of boats under
75 feet that use a centrifuge to handle fuel separation
tasks. Why do you think Alfa Laval build one the size of a
gallon milk jug? Your personal view and experience does not
define the marine industry in the 21st century.

Do you also use a nephalometer to
arrive at when the centrifugation is complete?

Once through will do.

As an aside .... a water emulsion will enhance the combustion
efficiency by increase of the apparent cetane number of the fuel, or
the octane number in a gasoline engine.

Water does not increase the cetane number ... do you know
what that means anyway?

Water serves to reduce the temperature of combustion and
thereby reduce the formation of oxides of nitrogen in a diesel.

Its the FREE water thats the
'problem' as simply 'slugs' of free water simply do not burn.

Got that one wrong too. There are several techniques
available in large diesels that layer the fuel and water
injected, and another that injects water first then fuel.

Let's stick to filtration and fuel polishing. If you want to
have a snit go chat with K over on rec. boats.

Rick

"Rick" wrote in message
k.net...
Rich Hampel wrote:

The use of a centrifuge on the small volume boat tankage .... borders
on ludicrous.

your opinion is not universal. Besides, we were writing
about FUEL POLISHING ... an activity normally performed
alongside a dock at rather extended intervals.

Actually, we are talking about permanently installed polishing systems
that run for extended periods of time. In general, they run the entire time
the engine iss running and also when the boat is sitting at anchor or at a
dock they run for several hours per week.

Centrifuges are extreme high maintenance rotating and
power consuming equipment

Just because you don't like them ... and you have a peculiar
vision of "extreme" maintenance.

Not practical for the type of system we are talking about here.

and do NOT effect total removal/separation of
emulsions. If you have enough power to run a centrifuge, then I
suggest that you rip out the fossil fuel engine and simply replace with
an electric motor for propulsion.

A rather extremist position. There are plenty of boats under
75 feet that use a centrifuge to handle fuel separation
tasks. Why do you think Alfa Laval build one the size of a
gallon milk jug? Your personal view and experience does not
define the marine industry in the 21st century.

Do you also use a nephalometer to
arrive at when the centrifugation is complete?

Once through will do.

As an aside .... a water emulsion will enhance the combustion
efficiency by increase of the apparent cetane number of the fuel, or
the octane number in a gasoline engine.

Water does not increase the cetane number ... do you know
what that means anyway?

Water serves to reduce the temperature of combustion and
thereby reduce the formation of oxides of nitrogen in a diesel.

Its the FREE water thats the
'problem' as simply 'slugs' of free water simply do not burn.

Got that one wrong too. There are several techniques
available in large diesels that layer the fuel and water
injected, and another that injects water first then fuel.

Let's stick to filtration and fuel polishing. If you want to
have a snit go chat with K over on rec. boats.

Rick

I don't think the typical Walbro fuel pump can pull such a vacuum.

Doug

"Rich Hampel" wrote in message
...
Another good reason NOT to pull vacuum on fuels and other volitile
liquids is that if the vacuum exceeds the vapor pressure of the fluid
the liquid with boil (flash) or you will separate out the lighter
fractions (lighter weight hydrocarbons). If youve ever had a gasoline
that had 'vapor-lock' problems you'll understand this phenomenom. I
dont have by me at this time a listing of the vapor pressure range of
#2 diesel fuel but you must understand that #2 is a mix of various
fractions. From that standpoint alone and the potential of 'flashing
by vacuum application make vacuum a less conservative approach to fuel
delivery systems.

I don't think the typical Walbro fuel pump can pull such a vacuum.

Doug

"Rich Hampel" wrote in message
...
Another good reason NOT to pull vacuum on fuels and other volitile
liquids is that if the vacuum exceeds the vapor pressure of the fluid
the liquid with boil (flash) or you will separate out the lighter
fractions (lighter weight hydrocarbons). If youve ever had a gasoline
that had 'vapor-lock' problems you'll understand this phenomenom. I
dont have by me at this time a listing of the vapor pressure range of
#2 diesel fuel but you must understand that #2 is a mix of various
fractions. From that standpoint alone and the potential of 'flashing
by vacuum application make vacuum a less conservative approach to fuel
delivery systems.

most single stage pumps will deliver approx 6" vacuum when
'deadheaded', at least thats what you design for as a maximum. .....
unless you have the manufacturers documents that include 'slip', etc.


In article , Doug Dotson
wrote:

I don't think the typical Walbro fuel pump can pull such a vacuum.

Doug

"Rich Hampel" wrote in message
...
Another good reason NOT to pull vacuum on fuels and other volitile
liquids is that if the vacuum exceeds the vapor pressure of the fluid
the liquid with boil (flash) or you will separate out the lighter
fractions (lighter weight hydrocarbons). If youve ever had a gasoline
that had 'vapor-lock' problems you'll understand this phenomenom. I
dont have by me at this time a listing of the vapor pressure range of
#2 diesel fuel but you must understand that #2 is a mix of various
fractions. From that standpoint alone and the potential of 'flashing
by vacuum application make vacuum a less conservative approach to fuel
delivery systems.

most single stage pumps will deliver approx 6" vacuum when
'deadheaded', at least thats what you design for as a maximum. .....
unless you have the manufacturers documents that include 'slip', etc.


In article , Doug Dotson
wrote:

I don't think the typical Walbro fuel pump can pull such a vacuum.

Doug

"Rich Hampel" wrote in message
...
Another good reason NOT to pull vacuum on fuels and other volitile
liquids is that if the vacuum exceeds the vapor pressure of the fluid
the liquid with boil (flash) or you will separate out the lighter
fractions (lighter weight hydrocarbons). If youve ever had a gasoline
that had 'vapor-lock' problems you'll understand this phenomenom. I
dont have by me at this time a listing of the vapor pressure range of
#2 diesel fuel but you must understand that #2 is a mix of various
fractions. From that standpoint alone and the potential of 'flashing
by vacuum application make vacuum a less conservative approach to fuel
delivery systems.

Doug Dotson wrote:

Actually, we are talking about permanently installed polishing systems
that run for extended periods of time. In general, they run the entire time
the engine iss running and also when the boat is sitting at anchor or at a
dock they run for several hours per week.

OK, in that case I would look very closely at the Alfa Laval
unit. It is very small, 110VAC low power. No filter beats a
centrifuge for use like that.

If I really wanted to do it right I would put one on the
lube oil as well.

Rick

Doug Dotson wrote:

Actually, we are talking about permanently installed polishing systems
that run for extended periods of time. In general, they run the entire time
the engine iss running and also when the boat is sitting at anchor or at a
dock they run for several hours per week.

OK, in that case I would look very closely at the Alfa Laval
unit. It is very small, 110VAC low power. No filter beats a
centrifuge for use like that.

If I really wanted to do it right I would put one on the
lube oil as well.

Rick

Jere Lull wrote:

ONLY if you're only looking at the filter.

Did you somehow miss this?

The element cannot possibly know what mechanism is used to
establish fluid flow through the filter.

Did I write filter housing?


Rick