Fuel Polishing Systems Pre/Home Made.

[Chief Engineer]

I have been doing some research on fuel polishing systems that are designed for in-vessel installation. I have looked at packages as well as some homemade setups on the internet.

I am familiar with the large setups that can be "rolled" to your boat as well as centrifuges (on the vessel in the picture). (We also have a polishing system that uses 2 Racor 1000 series filters which are rated for 180 GPH
running off of a 110 volt gear pump.

All I can say is that the "factory made" units seem rather "ambitious" in their flow rates.

Suffice it to say that even with clean fuel, I find it hard to believe that these flow rates of 3 GPM/180 GPH can be achieved with a 12 volt pump.

Don't intend to ignite a firestorm here......just looking for insights/experience.

[GordMay]

Common "cheapo" 12VDC Bilge Pumps are ubiquitous in ratings from 500 - 2000 GPH; so I shouldn't think <200 GPH should present any particular technical problem.

[Bloodhound]

I'm looking at building an onboard system using a Racor FG500 filter with 2 um element and a 12V diaphragm pump with 8 ft suction lift. I also intend to use the pump to help bleed the injection pump when required. The Racor 500FG is rated at 60 GPH and the pump will open flow 100 GPH. Should the pump be throttled to match the filter flow capacity or should I just find a closer match, or does the mismatch really matter that much? More importantly, what will two series filters do that one will not except extend the run time of the polishing cycle? Would it make more sense to put two Racors in parallel and get a better match to the pump's capacity? If in series, would it make sense to use a 10 um element first, followed by a 2 um? Or is a single Racor quite sufficient?

[colemj]

Originally Posted by Chief Engineer

All I can say is that the "factory made" units seem rather "ambitious" in their flow rates.

Suffice it to say that even with clean fuel, I find it hard to believe that these flow rates of 3 GPM/180 GPH can be achieved with a 12 volt pump.

Don't intend to ignite a firestorm here......just looking for insights/experience.

I made a fuel polishing system using a 12V Reverso gear pump and a Racor 1000. The gear pump is rated 180 GPH. I have measured the flow rate installed in the system and the flow is as rated by the manufacturer.

I do share your skepticism around some of the commercial systems using small Perolator or Walbro pumps. I think these pumps pump much less than rated when installed in a system with any resistance.

Mark

[colemj]

Originally Posted by Bloodhound

I'm looking at building an onboard system using a Racor FG500 filter with 2 um element and a 12V diaphragm pump with 8 ft suction lift. I also intend to use the pump to help bleed the injection pump when required. The Racor 500FG is rated at 60 GPH and the pump will open flow 100 GPH. Should the pump be throttled to match the filter flow capacity or should I just find a closer match, or does the mismatch really matter that much? More importantly, what will two series filters do that one will not except extend the run time of the polishing cycle? Would it make more sense to put two Racors in parallel and get a better match to the pump's capacity? If in series, would it make sense to use a 10 um element first, followed by a 2 um? Or is a single Racor quite sufficient?

The match is important. The Racors have a centrifugal component and specific filter surface area that is designed for a particular flow rate. There is actually a minimum flow rate needed for the centrifugal separation to work well.

Two filters in series won't extend the run time between changes. Put the filters in parallel for that.

Mark

[btrayfors]

Here's a system I built in my basement a few months ago. Seems to work fine. Took a lot more work than I intended, though :-) And, it wasn't cheap. However, given that commercial units are $2,000 plus it wasn't too bad.

We put 50' fuel hoses on it and took it for a spin, polishing some very dirty fuel removed from a boat. Did the job just fine, but it doesn't look quite as spiffy now with all the black sediment :-)

Gallery :: Miscellaneous 2007 :: Filter_0342

Bill

[Bill_E]

That looks almost like Chardonnay in the filter bowl...must be pre use!

Van Sant has some suggestions for fuel systems and pumps in the Gentleman's Guide. They look pretty simple and effective to me. I wonder if anyone has any comments on his suggestions. I'm thinking of implementing them on my boat.

Bill

[Chief Engineer]

Do you start with 30 mic and 2 mic final.

How long does your primary filter last....(ballpark is ok)

Is that a flowmeter or hourmeter at the bottom?

Thanx

[Chief Engineer]

Do you have a link or photo?

Originally Posted by wlearl

That looks almost like Chardonnay in the filter bowl...must be pre use!

Van Sant has some suggestions for fuel systems and pumps in the Gentleman's Guide. They look pretty simple and effective to me. I wonder if anyone has any comments on his suggestions. I'm thinking of implementing them on my boat.

Bill