Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-05-2015, 02:48   #46
Registered User

Join Date: Jul 2013
Location: San Diego, CA
Posts: 3,157
Re: Fuel Filtration Systems

Quote:
Originally Posted by gts1544 View Post
Mark,
Thank you for your reply. We cleaned the tank several years ago (more than 5) as the 10 members had not been using biocide on a regular basis. After the tank cleaning, we began using it with every fill (I hope).

My problem was a badly surging engine, which I was able to limp back to our base mooring. Our regular mechanic came aboard and promptly changed out both filters (the Racor was definitely filthy) but I did not get a good look at the Perkins filter, so the result there is inconclusive, nor had I been monitoring filter change frequency, which I will now do. That definitely solved the surging problem.

Since I am the member responsible for the maintenance of the boat, I will confer with our mechanic to track the filter changes to see if a tank cleaning is necessary. I would prefer to use the 10 micron as the primary, but am concerned that the frequency of clogging would become too often.


Does anyone know the micron rating of the Perkins #26561117 Secondary filters?

Thanks again for your input!

gts1544 - George

The answer to your question lies entirely in how clean is your diesel source. 10 microns is pretty tight for a pre filter. If you're getting really clean fuel, you could get pretty long filter change intervals with a 10 micron. But if you get one bad load of fuel, you could be clogging 30 micron prefilters every other day. It happened to me, and it sucks! I normally run a 30 micron pre filter, lift pump, 10 micron post filter (all mounted together) which leads to the stock filter (allegedly a 10 micron, but testing proved it was more like a 25-30 micron, leading GMC to switch to a "2nd generation" filter.) I ended up stalled at the side of the road changing filters every few days until I burned up all of the bad fuel (fortunately, not a full tank.) I still carry 6 spare filters with me just in case, plus 3 cases of spares at home.

I'd stick with 30 micron pre, 10 micron post. From what I've found, your Perkins filter is rated 4 micron nominal.


Another factor that no one discusses is filter element wetting due to vacuum vs pressurized.

My "pre and post" filters are actually mounted on a lift pump, but the lift pump is first, and it's within 1 ft of the tank. A normal diesel fuel system pulls a vacuum all the way from the tank to the engine. Some may have a lift pump on the engine, a few people install a lift pump near the tank as I did.

The difference is, when a filter is under vacuum, fuel will rise up in the filter only high enough to overcome the resistance of the filter media, maybe the bottom 1/4 or 1/3 when the filter is new. As that section of filter media gets dirty and clogs, resistance rises, fuel rises higher, and wets the filter media higher and higher until the media is fully clogged, or water starts filling the filter, etc. Most of the time, the upper portion of the filter and media are dry, unused until the very end.

I prefer a pressurized system because it's easier for air to enter than diesel to escape, so a microscopic leak will introduce air in your fuel lines, making for hard starting, rough running and it only gets worse as the filter resistance increases.

A pressurized system with equal fitting tightness probably won't leak fuel, if it does, it's easy to spot and fix compared to a vacuum leak. More importantly, it will fill the filter bowl and use all of the filter media simultaneously for filtration, resulting in less restriction to flow (admittedly more of an issue on high performance diesels) and the knowledge that if the filter is clogged, you got more service life out of it vs a weak vacuum that can't over come 1/2 of the filter media, perhaps because it was poorly mounted.

I also like the way it starts: like a gasser. Turn the key, and it fires up instantly, in less than 1 revolution. I get nervous when something takes more than a couple of revolutions to start.
__________________

__________________
socaldmax is offline   Reply With Quote
Old 25-05-2015, 02:59   #47
Registered User

Join Date: Jul 2013
Location: San Diego, CA
Posts: 3,157
Re: Fuel Filtration Systems

Quote:
Originally Posted by Dockhead View Post
A well-reasoned and intelligent response; thanks for that. It makes for a good debate

The more subtle effects at play are definitely "above my pay grade" -- I'm not an engineer. But the calculations I have shown will give the theoretical maxima just fine, I think. You seem to agree here:

"Bare in mind that the amounts of water we are discussing are tiny, only a few grams in a year. Leaks and bad fuel are MUCH larger issues. But in terms of corrosion and growing bugs, a few grams can make a difference."

I guess that would be the crux of the issue, wouldn't it? If we agree that tank breathing can amount to just a few grams of water a year, amounting to a few tens of PPM, could it possibly matter? When it's a fraction of the fuel's capacity to absorb water? I will certainly listen with an open mind, if you have an explanation for why that could be so.


I clean out my tank every two years. In six years, I have never found a drop of water either in the tank or in my Racors. I am pretty sure that this is because my fuel filler is (wisely; thank you Bill Dixon) located above deck level, with a positive locking cap, and behind a flap, where sea water on deck can't get at it, and because I buy fuel from carefully selected and good quality providers (a luxury not available to everyone, I realize).

I don't keep my tank full, and since it holds almost 700 liters I often go for many months without filling it. Less fuel in the tank means less fuel to absorb water, and not intentionally storing fuel for long periods means I typically have drier fuel on board.

My tank, like that of most cruisers, would hardly breathe anyway. It's not in the bilge, but it is below the waterline, with temperature much more influenced by water temp than outside air temp. Between day and night hardly a degree C of difference (judging by the temperature sensor in my engine room).

To get back to the practical side of the question.
I agree with you, tank breathing is a negligible source of water condensation.

I think fuel consumption is a greater source of air intake to the tank, and possibly moisture along with it, depending on where the tank vent is located.

Where are most fuel tanks vented? Below decks or above deck? Is there something in the vent line preventing water or moisture from getting into the tank?
__________________

__________________
socaldmax is offline   Reply With Quote
Old 25-05-2015, 03:02   #48
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,735
Re: Fuel Filtration Systems

Quote:
Originally Posted by noelex 77 View Post
Thanks. I will take a look at it. So many decisions, each with some compromise involved.

I was going to request a fuel fill in the cockpit combing, but as it happens the boat is normally built with standpipes for fuel and water topped with an overlapping and very waterproof looking cap.

A simple system, not quite foolproof, but much better than the normal flush inlets.

That looks pretty good. Is that a rubber cap over a screw-in o-ringed cap? So a double cap? If so, then that plus standing well proud of the deck would probably be ok. Downside would be stubbed toes and snagged lines.
__________________
Dockhead is offline   Reply With Quote
Old 25-05-2015, 20:55   #49
Registered User

Join Date: Aug 2007
Location: West Indies
Boat: Burger 74' motor yacht, 65 foot 12 metre, Flicka and sailing dinghy
Posts: 635
Fuel Filtration Systems

The Seaboard setup is what I would go for. I think Racor filters are obsolete, clog too quickly and are a mess to change. The spin on filter (Fleetguard) holds 7 times the crud as the Racor 1000.


Why can't things remain where i carelessly left them?
__________________
To a hammer, everything looks like a nail.
dohenyboy is offline   Reply With Quote
Old 25-05-2015, 21:32   #50
Registered User

Join Date: May 2010
Location: Sydney Australia
Boat: Fisher pilothouse sloop 32'
Posts: 749
Re: Fuel Filtration Systems

Have you considered adding a sedimenter (looks like a water separating filter without the filter) between the racor and tank? Surprising how much crap it collects and it doesn't get to the filter.
__________________
Rob aka Uncle Bob Sydney Australia.

Life is 10% the cards you are dealt, 90% how you play em
Uncle Bob is online now   Reply With Quote
Old 26-05-2015, 08:24   #51
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 12,373
Re: Fuel Filtration Systems

Quote:
Originally Posted by Kenomac View Post
This subject comes up on the forum over and over again. Install something like this and the problem goes away forever. $1500-$2000 installed and will pay for itself the first time you get a bad tank of fuel. Dual Racors that feed the engine and generator with a switch lever in case one filter becomes clogged plus the fuel polishing system filter on the right. Fuel can be polished anytime with or without the engine running, it's completely independent. Polishes 150 gallons per hour using a Reverso polishing module/pump.
Regarding fuel polishing, it has never been completely clear to me exactly what fuel polishing is. Is it just pumping your fuel through a standard water separator/filter or is polishing something more?

I already have the dual Racor and have the old single Racor left over from the upgrade and an backup electric fuel pump. What if I plumb in the old Racor to recirculate the diesel in my tanks? Is that polishing? Seems like it would at the very least remove crude, sediment and any accumulated water that might have snuck into the system.
__________________
The water is always bluer on the other side of the ocean.
skipmac is online now   Reply With Quote
Old 26-05-2015, 09:12   #52
Senior Cruiser
 
Kenomac's Avatar

Cruisers Forum Supporter

Join Date: Jan 2012
Location: Somewhere in the Adriatic Sea
Boat: Oyster 53 Cutter
Posts: 8,510
Re: Fuel Filtration Systems

Yes, that would be polishing. But something you should consider, on our system we have the fuel polishing pick up at the lowest point of the tank, and the return on the other side of the tank, so that it creates a washing effect over the bottom of the fuel tank. If you try to use your existing pick up and return, the fuel pick up is normally located a little higher up off the fuel tank bottom, so as not to pick up crud off the bottom. You want the fuel polisher to get that crud off the bottom.
__________________
Kenomac is offline   Reply With Quote
Old 26-05-2015, 10:13   #53
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Fuel Filtration Systems

Quote:
Originally Posted by dohenyboy View Post
The Seaboard setup is what I would go for. I think Racor filters are obsolete, clog too quickly and are a mess to change. The spin on filter (Fleetguard) holds 7 times the crud as the Racor 1000.
The amount of "crud" fuel filters can filter before the restriction rises enough to cause problems for the engine is an important parameter.

With a diesel bug problem on a neighbouring boat, I have seen filters clog in as little as 10-15 min after the fitting of new element. It is obviously preferable to avoid a diesel bug problem in the first place, but it does seem to becoming a very common problem (perhaps with use of bio fuels?).

As a belt and braces approach, as well as doing everything possible to possible to prevent the problem occurring, it is desirable to fit a large (duel) primary filter. My 54hp has a Raycor 900 (with a Raycor 500 that can be switched as a back up while the engine is running). The large 900 element has a much greater crud tolerance. (From memory it was 6-7 times the Raycor 500).

If there was a filter with 7 times the crud tollerance of the Raycor 1000 it would certainly be a great option for my next boat, so I am interested in Fleetgard's claims. However, I am also a little skeptical. The Raycor 1000 is an enormous filter. It is hard to imagine a spin on filter with more surface area, perhaps that is not the only factor that determines the "crud tolerance" but I wonder if Fleetgard are using a different standard, or test parameters?

If you have any references for the claims I would be interested in reading them.
__________________
noelex 77 is offline   Reply With Quote
Old 26-05-2015, 10:21   #54
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 12,373
Re: Fuel Filtration Systems

Quote:
Originally Posted by Kenomac View Post
Yes, that would be polishing. But something you should consider, on our system we have the fuel polishing pick up at the lowest point of the tank, and the return on the other side of the tank, so that it creates a washing effect over the bottom of the fuel tank. If you try to use your existing pick up and return, the fuel pick up is normally located a little higher up off the fuel tank bottom, so as not to pick up crud off the bottom. You want the fuel polisher to get that crud off the bottom.
Thanks.

Have already been looking at the pickup issue. Definitely in my tanks (two) the pickup is about an inch higher than the lowest point. The tanks have a sloping bottom so I'm not losing access to much of the fuel and the low spot acts like a sump so I can occasionally suck out whatever collects in the bottom. But for polishing I agree it would be best to pickup at the lowest point. That however will require a bit more plumbing to accomplish than just hooding in to the existing pickup.

Having two identical tanks is a nice benefit since I can polish all the fuel from one tank to the other when one is empty.
__________________
The water is always bluer on the other side of the ocean.
skipmac is online now   Reply With Quote
Old 26-05-2015, 11:35   #55
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: Fuel Filtration Systems

Noelex, I know you asked this and don't think anyone answered, but the name of the division of Parker that makes these filters is called and spelled "Racor", not "Raycor".

Racor Filters - Parker

Perhaps in other countries the spelling is different?

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 26-05-2015, 11:56   #56
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,735
Re: Fuel Filtration Systems

Quote:
Originally Posted by noelex 77 View Post
The amount of "crud" fuel filters can filter before the restriction rises enough to cause problems for the engine is an important parameter.

With a diesel bug problem on a neighbouring boat, I have seen filters clog in as little as 10-15 min after the fitting of new element. It is obviously preferable to avoid a diesel bug problem in the first place, but it does seem to becoming a very common problem (perhaps with use of bio fuels?).

As a belt and braces approach, as well as doing everything possible to possible to prevent the problem occurring, it is desirable to fit a large (duel) primary filter. My 54hp has a Raycor 900 (with a Raycor 500 that can be switched as a back up while the engine is running). The large 900 element has a much greater crud tolerance. (From memory it was 6-7 times the Raycor 500).

If there was a filter with 7 times the crud tollerance of the Raycor 1000 it would certainly be a great option for my next boat, so I am interested in Fleetgard's claims. However, I am also a little skeptical. The Raycor 1000 is an enormous filter. It is hard to imagine a spin on filter with more surface area, perhaps that is not the only factor that determines the "crud tolerance" but I wonder if Fleetgard are using a different standard, or test parameters?

If you have any references for the claims I would be interested in reading them.
Noelex, I am not sure that fuel polishing systems are really needed if you are not planning to sail in the third world. Provided you can design your fuel tank right. What you need is a decent sump with a proper drain in it – yes, I know, forbidden by various rules. Or at least a dip tube which gets right down to the bottom of the sump. Then you can draw off the dregs from time to time, fairly frequently, to examine them and see what’s going on in the bottom of your tank. You can draw off any water which collects before it has time to do any harm.

That will prevent the problem from forming in the first place. The other measures just treat the problem after it has already occurred. I’m not saying there’s anything wrong with fuel polishing, and if the system is done right (like on Kenomac’s boat, with the pickup quite low) it will also partially fulfill this primary function, but if you have another, more direct means to detect and get the water out promptly, I don’t think endless filtering and refiltering of the fuel is really necessary. Remember also that your engine is a fuel polisher – recirculating a large volume of fuel all the time through your filter system.
__________________
Dockhead is offline   Reply With Quote
Old 26-05-2015, 12:11   #57
Registered User

Join Date: Oct 2009
Posts: 647
Re: Fuel Filtration Systems

Seems to me that the normal operation of the engine would polish the fuel adequately considering that a large percentage of the fuel is returned to the tank. Not sure what the percentage is and probably varies among engines.
__________________
lancelot9898 is offline   Reply With Quote
Old 26-05-2015, 12:34   #58
Senior Cruiser
 
Kenomac's Avatar

Cruisers Forum Supporter

Join Date: Jan 2012
Location: Somewhere in the Adriatic Sea
Boat: Oyster 53 Cutter
Posts: 8,510
Re: Fuel Filtration Systems

Quote:
Originally Posted by Dockhead View Post
Noelex, I am not sure that fuel polishing systems are really needed if you are not planning to sail in the third world..........(edit) I don’t think endless filtering and refiltering of the fuel is really necessary. Remember also that your engine is a fuel polisher – recirculating a large volume of fuel all the time through your filter system.
But it does end the problem and concern once and for all. For the cost to rid yourself of one bad tank of fuel and the repairs associated with it... not to mention the hassle in dealing with the situation, you can have a fuel polishing system.... and stop worrying about the cause, spending money on biocides, etc. etc.

Consider it preventative maintenance. I got the idea from other CF full time cruisers.
__________________
Kenomac is offline   Reply With Quote
Old 26-05-2015, 12:43   #59
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 12,373
Re: Fuel Filtration Systems

Quote:
Originally Posted by lancelot9898 View Post
Seems to me that the normal operation of the engine would polish the fuel adequately considering that a large percentage of the fuel is returned to the tank. Not sure what the percentage is and probably varies among engines.
The key phrase here is normal operation. Lots and lots of boats sit at the dock for weeks or months and might not use a full tank of fuel in a year. Engine operation consists of running for half hour or so to get from the dock and out the channel to hoist sails.

For this kind of use there won't be enough throughput to cycle the fuel and clean it.
__________________
The water is always bluer on the other side of the ocean.
skipmac is online now   Reply With Quote
Old 26-05-2015, 12:52   #60
Senior Cruiser
 
Kenomac's Avatar

Cruisers Forum Supporter

Join Date: Jan 2012
Location: Somewhere in the Adriatic Sea
Boat: Oyster 53 Cutter
Posts: 8,510
Re: Fuel Filtration Systems

According to Reverso, the manufacturer of our fuel polishing system, the fuel in a single tank system needs to be circulated through the filter three times in order to be considered polished unless you have a two tank system with a day tank, then only one time is required.
__________________

__________________
Kenomac is offline   Reply With Quote
Reply

Tags
fuel

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Household vs Marine-Specific Water Filtration Systems Punx Provisioning: Food & Drink 0 29-08-2011 15:09
Bash's Fuel Filtration System markpierce Engines and Propulsion Systems 0 28-07-2011 17:15
air filtration gettinthere Engines and Propulsion Systems 12 28-10-2008 17:03
Pre-Fuel Filling Filtration. stillbuilding Engines and Propulsion Systems 8 15-09-2008 08:54
Racor Filtration jjorg Engines and Propulsion Systems 23 05-12-2007 06:55



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:20.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.