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Rick
 
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Default Fuel Polishing again.

Steven Shelikoff wrote:

However, Rich recommends that fuel be pushed through due to some
tendency of the filter media to work better in that mode.


I recommend sucking fuel through the primary separator
filters. The much finer secondary filters normally require
pressure feed to assure adequate flow through a reasonable
sized element. The canned type of filter is designed to work
under high pressure and are used very successfully and
safely in that mode by nearly every manufacturer of large
and small engines.

During many years of operating such filters in marine
applications the only time I have see one leak badly was
when the discharge from the filter was closed against the
positive displacement pump serving it. And in that case all
that happened was the rubber sealing ring blew out. Opening
the valve stopped the leak immediately.

... discounting all other aspects at hand such as the pump
emulsifying the fuel before it gets to the filter, why does the filter
media care which side the pump is on? Fuel is being pushed through it
either way, either by the pump with a higher pressure on the inlet or
the atmosphere with a higher pressure on the inlet.


The element cannot possibly know what mechanism is used to
establish fluid flow through the filter. The only thing the
filter sees is rate of flow and as it clogs, differential.
Anyone who claims otherwise is ignoring some other factor or
talking BS.

It does not take much imagination to see that the same flow
and pressure can be applied to a filter housing by gravity,
a pump discharge or a pump suction.

Rick