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Water Seperation

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edcourter

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Does a fuel/water separator work like a sediment bowel with a drain at the bottom (where fuel will always follow after the water) or does it actually separate the water into a separate area with a drain? In the last case, if there was no water, nothing would exit the drain and fuel would never exit the drain. Or are there both kinds?
 
The water settles in the bottom you can get a clear plastic bowl with a drain cock but you still may get some fuel when you go to drain it. I suppose you could run it through a centrifuge and separate it that way. I know big diesel boats scrub their fuel but is it practical for a small boat?
 
Ayuh,.... It's a sediment bowl affair,....

Gravity drops the water to the bottom, fuel flows out the top,.....

Clear fuel bowls are illegal on a gasoline powered boat,....

Diesel is polished mostly to remove the algae that forms in diesel,.....
 
Well explained.

Note that "White Gook' (the liquid created by ethanol, moisture and time) will go right through filters and separators since it's apparently similar in specific weight to gasoline.

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Jeff
 
I'm trying to re-do a leak free fuel line which has an after market separator in the system. It doesn't leak but some venders have different units for inboards, no petcock. Mine has the petcock. I'm considering simplifying the plumbing by eliminating it (4 less leak places) and just changing (or dumping) the stock mercruiser cartridge very often. I also noticed that the mercruiser separator shows a double O-ring at the top. Any other canisters have this?
 
Perhaps you are thinking about the Parker/RACOR fuel filter system.
The Parker/RACOR fuel filter system uses a cyclonic principle to centrifugally separate the water from the gasoline, eventually placing any water into the lower bowl where it can be drained.

If you have an enclosed Gasoline I/B and enclosed fuel filter, USCG regulations require the metal bowl with a threaded drain plug.

If you have a Gasoline O/B and a non-enclosed fuel filter, USCG regulations allow the use the filter with the see-thru plastic bowl and petcock style drain.


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edcourter said:
I'm trying to re-do a leak free fuel line which has an after market separator in the system. It doesn't leak but some venders have different units for inboards, no petcock. Mine has the petcock. I'm considering simplifying the plumbing by eliminating it (4 less leak places) and just changing (or dumping) the stock mercruiser cartridge very often. I also noticed that the mercruiser separator shows a double O-ring at the top. Any other canisters have this?
Click to expand...

Ayuh,.... You shouldn't have that much water in yer fuel in the 1st place,....

Stop the water from gettin' into yer fuel, 'n annual filter changes should be more than enough,.....
 
bondo said:
Ayuh,.... You shouldn't have that much water in yer fuel in the 1st place,....

Stop the water from gettin' into yer fuel, 'n annual filter changes should be more than enough,.....
Click to expand...

Yes.... I fully agree.
Find out how/why any water is getting into your fuel tank.
Look at the O-ring seal underneath the fuel fill cap.
Make sure that the fuel tank vent line has a high-loop incorporated just above the vent fitting connection.
 
An inline Water Sep filter is a waste if you are using E-10 Fuel. We now take them out as they are ineffective. If you have water in your fuel you have bigger problems.
 
I had assumed some of the water was coming in from the pump.
So far I have avoided the E-10. ​
The vent loop looks good and I'll replace the filler gasket. It sounds like I should also replace the petcock with a plug per USCG, makes sense, Thanks all, I started out installing a whistle and thought I'd go threw the whole system. Seemed like such a simple and economical job?? gold plated rubber?? Be glad I did on the water!
 
You mention petcock...... I am still unclear as to which fuel filter system your boat is equipped with.

This is my take on Marine gasoline fuel filters:
 

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fastjeff said:
What's different between your top two choices?

Jeff
Click to expand...

jeff, if your question is aimed at me..... there is a big difference between the RACOR and the industry standard fuel filter.

The RACOR will actually separate h2o from the gasoline via a cyclonic centrifugal action. Once the bowl is drained, the unit can continue functioning.

Whereas with the standard unit, it relies on the absorption ability of the filter media. Once saturated, that filter is done.



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The combo of E-10 fuel and a fuel tank that is allowed to sit almost empty causes a physical process whereby moisture from the atmosphere is literally sucked into the tank by temperature cycling and is absorbed by ethanol laced gas and eventually will saturate and precipitate into the bottom of the fuel tank. Some cartridge style fuel filter/separators will "remove" water from the fuel. More than once, I've been able to drain the water out of the cartridge and continued operating OK. Another source of water in fuel is buying fuel from marinas that do no properly and routinely test and maintain their fuel tanks. More than once I've had my fuel filter "filled" with water and had engine problems within an hour or two of engine operation after filling up at one of these sloppy marinas. Dumping the water out of a standard cartridge fuel separator/filter while "at sea" is problematic. The "best" solution is the Parker/RACOR system. They even have a filter/separator bowl (metal) replacement for the usual cartridge filter. While it will screw on and replace an existing cartridge element, sometimes there isn't enough room with an engine mounted setup to do this. Measure before buying, remembering that you need enough clearance under the bowl mount to thread the new combo on... and to get a can under it to drain it.
 
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