Installing New Hatches In Fuel Tanks

[Dockhead]

After the recent discussion about cleaning fuel tanks, I have started to think again about installing a fuel polishing system in my boat to continuously clear the water out of the bottom. This seems to me to be a superior approach to keeping crud out of your tank. If the water is not allowed to build up in the first place, then there's not much way for crud to form.

By the way -- a little drift from my question -- wouldn't it make sense to have dual pickups -- one at the normal level, and one quite a bit higher, for when your tank is reasonably full but you think you might get into some rough weather? This would be easy to do with a simple changeover; also would give you a backup fuel pickup in case one gets blocked, provided you have plenty of fuel in your tank.


My question is this -- is it feasible to install a new hatch and pickup with the tank in situ and full of fuel? How do you keep aluminium chips from flying into the fuel?

If it is mandatory that all the fuel should be pumped out and the tank cleaned out by hand afterwards, then that nixes it for me -- I don't have good enough access to clean out the tank by hand, without ripping the boat apart.

If it is feasible, I might take the opportunity to install a second fuel level sender, as well -- a Maretron ultrasonic one. That would be great -- to have fuel level in the network besides fuel flow (just installed that), and an accurate ultrasonic measurement to boot. The sender is amazingly cheap (never thought I would ever say that about any Maretron product).

[Strait Shooter]

I don't see anyway of doing it but to empty the tank and be able to scrub it out afterwards.

[GordMay]

“... Never install the Access Plate System on tanks containing gasoline or other highly flammable liquids or gasses...”

➥ Seabuilt - Access Plate Systems

“... Do I need to drain the tank completely before I install the Access Plate System?
No, but be aware that the process of cutting and drilling on the tank will allow minor bits of debris to fall into the tank. It is best to drain the tank and clean it out completely before you finish the installation...”

➥ Seabuilt - Access Plate Systems

[tamicatana]

We're in the process. Had plates C&C'd up. Oval, to allow easy installation. Diesel tanks.

The plan is to shut the valve to the fuel line (to the engine). Empty tank. Fill tank with water. Use holesaw and grinder to cut hole. Clean tank. Install plate. Empty water and refill. Done.

I will not even consider anything more complicated than the sight tubes I now have.

Now what has been installed and did save our cross-Gulf trip is a second filter. Actually it's a primary filter. It got the nasty, and does catch water as well. I have it before the separator.

McMaster 9875K216, 80 mesh screen (Impact resistant nylon clear bowl)

[NSboatman]

to do it right DH, it sounds like you're looking at some dis-assembly and cabin carpentry... I'm not aware of any system out there that can capture the saw shavings effectively on the backside of a blade, and I'd be a little suspicious of any that claimed it...

if you're going to put in a polishing system, may i suggest that you go with a bigger flow rate and larger piping that is typically seen on these systems off the shelf. the reason I suggest this is because a very important aspect of polishing is to set up enough of a flow in the tank to do a bit of scouring, which can dramatically improve the performance of the polishing.

Many systems are sized to pull a tiny amount of power and slowly, ever so slowly, turn over the fuel in the tank using very small pumps. This is nice and quiet and uses very little power, but doesn't do the best job. If you want to really polish the fuel, you need high-capacity filters, large lines, a high-flow pump and to give it the juice it needs to turn over the fuel in the tank in a reasonable period. For industrial tanks, we're looking at no less than a full turn over in 8 hours (which is a lot of flow on a 15,000 gal tank!). the key is to set up a good, scouring flow. I'm not talking about getting it all foamy and entraining air - just setting up a very good flow and scouring in the tank. you'd be amazed at what we pull up in tanks when we do this.

good luck! Polishing is definitely required...

[Kenomac]

We were in the same position as you five months ago with dirty tanks and deciding if the solution was a fuel polishing system. So far we haven't installed the polisher and probably won't this season, but you really need to get all crud out of the tank before you do anything. The polisher won't do that by itself, but here's a link to the system I was going to install at some point: http://reversopumps.com/sales/fuel-polishing-kit

The bottom line: The fuel polisher won't do you any good unless you first start out with clean tanks. Before the polishing system, look into installing a new larger access hatch(s). If you do install a fuel polishing system, it needs to be able to move enough fuel through the filters in order to get the job done; anything less than something like the Reverso system would just be a "feel good" waste of money. Basically, the Reverso is just a big pump that will move the fuel though an existing Racor filter system as I understand it.

[Navatech]

On fuel polishing, yes, one way is to offload the fuel, clean the tank, polish the fuel and return it to the tank. HOWEVER, there is no way of guaranteeing that the fuel won't get contaminated again. And then you have to do it all over again.

FWIW, my setup is as follows:

I have a T valve on the fuel pickup line. It either connect the primary (engine's mechanical) fuel pump to the fuel pickup line or it connects the (electric) polishing pump to the fuel pickup line.

I have a T valve on the fuel return line. It either connect the engine's fuel return to the tank's fuel return line or it connects the (electric) polishing pump's discharge to the tank's fuel return line.

The (electric) polishing pump and fuel purifier (installed before the first T valve on the fuel pickup line) will circulate the fuel tank's entire content roughly 30 times in a 24 hour period. I will start it up one day prior to taking out the boat. If the boat isn't used I'll run the system once every two weeks for 6 hours (timer). As the fuel purifier remains in line during regular operation the fuel continues to be polished while at sea.

As a result my Racors are completely clean (even though I have the 10 micron cartridges installed) and never show any water. I replace the Racor cartridge once per year.

I decided to go this route when I bought a boat that had been on the hard for roughly 30 months in the Caribbean (humid conditions are perfect for the fuel flora & fauna). The existing fuel (about 200 gallons) was a mess! The cost (with me doing the installation) was slightly less then I was quoted for a more standard solution (with a contractor doing the work).

The tanks were about 1/3rd full. I diluted the existing fuel with an equal amount of kerosine (jet fuel), added additives that were supposed to (and, I guess, did) kill and disperse the fuel flora & fauna and ran the polisher for a week. The first day I had to purge the fuel purifier every 2 hours. The second day I had to purge the fuel purifier every 3-4 hours. The third day I had to purge the fuel purifier every 6-9 hours. The next three days the fuel purifier purges gradually came down to once every 24 hours. The last day no purge was required. I then topped up the fuel tanks with regular diesel and used the fuel subsequently. No problems at all with that mixture (old fuel, kerosine and new fuel). No problems since then.

In fact, I have since purchased several times heavily water and microbial sludge polluted diesel at 10% of the value or less, run it through my system (diluted with kerosine and with additives) and then burned it off in my engines (DD 8V92TI's). No problems and great fuel saving cost. In fact, the money so saved paid (and then some) for the system!

I'm a happy camper with my system and will install it in any subsequent boat.

Notes:

• The fuel purifier doesn't require any power (other then for the circulating pump and water level alarm), elements or chemicals. Purging is the only required maintenance. I also have a water level alarm on it. Purging is one of my items on the getting ready for sea check list.
• The fuel purifier is preceded and followed by two T valves so can be bypassed with the turning of two valves. As an added value, and depending on how I set these valves, I can use the polishing system as a fuel priming/bleeding system
• Jet fuel can be used as a fuel for the DD's without any modifications to the engines. In fact, the US Navy is now running most of its diesels (including DD's) on JP (single fuel program). Kerosine and jet fuel are essentially the same. Most if not all diesels can run a mixture of 1/3rd kerosine and 2/3rd diesel without a problem. Kerosine and diesel are quite similar in their caloric values. The main difference is in that the diesel has higher lubricative values (important for your fuel injection system).

I'm a happy camper boater

As always, YMMV!

[GordMay]

Greetings and welcome aboard the CF, Navatech.

[Navatech]

Originally Posted by GordMay

Greetings and welcome aboard the CF, Navatech.

Thanks

[s/v Jedi]

I suppose I don't need to post my diagram with the optimum plumbing again

Find the lowest point of your tank (geeks have the bubble-level app on their iPhone for this ) which must be where the new pick-up tube must end. Cut the fuel pick-up tube so that it ends 4" from the bottom of the tank. Find a piece of diesel fuel rated hose that fits over the pipe and fasten it with dual ABA hose clamps. Now insert in into the tank and measure how much too long it is. Cut the hose 2" TOO LONG. (You'll end up with about 8" of hose total length) For final fastening, tilt it a bit then work it so that the 2" hose that doesn't fit in comes to lay flat on the bottom. Like the bottom of the letter J.

Before the whacking of the Jedi starts again : this is how pro' do it. That or a bottom sump with bottom connection.

cheers,
Nick.

[s/v Jedi]

Ah, I forgot about the polishing: Start using enzyme based fuel treatment (Startron etc.) and make sure to run the polishing pump plenty for the first day and then a bit every day. After some time, replace the filter element. Now, after you polish another week or so, check the filter element and it will tell you how bad it is. Keep polishing and maybe add another enzyme maintenance treatment after a month.

The enzymes work even when the fuel is just standing in the tank. This will actually clean the tank to a level that it is good enough. No biocide will do this.

[noelex 77]

Originally Posted by NSboatman

Many systems are sized to pull a tiny amount of power and slowly, ever so slowly, turn over the fuel in the tank using very small pumps. This is nice and quiet and uses very little power, but doesn't do the best job. If you want to really polish the fuel, you need high-capacity filters, large lines, a high-flow pump and to give it the juice it needs to turn over the fuel in the tank in a reasonable period. For industrial tanks, we're looking at no less than a full turn over in 8 hours (which is a lot of flow on a 15,000 gal tank!). the key is to set up a good, scouring flow. I'm not talking about getting it all foamy and entraining air - just setting up a very good flow and scouring in the tank. you'd be amazed at what we pull up in tanks when we do this.

good luck! Polishing is definitely required...

The advantage with a yacht, that is not present with a fixed tank, is that you you get a good scouring system, every time you go for an offshore sail.

[Dockhead]

Originally Posted by Kenomac

We were in the same position as you five months ago with dirty tanks and deciding if the solution was a fuel polishing system. So far we haven't installed the polisher and probably won't this season, but you really need to get all crud out of the tank before you do anything. The polisher won't do that by itself, but here's a link to the system I was going to install at some point: Fuel Polishing Module

The bottom line: The fuel polisher won't do you any good unless you first start out with clean tanks. Before the polishing system, look into installing a new larger access hatch(s). If you do install a fuel polishing system, it needs to be able to move enough fuel through the filters in order to get the job done; anything less than something like the Reverso system would just be a "feel good" waste of money. Basically, the Reverso is just a big pump that will move the fuel though an existing Racor filter system as I understand it.

I don't believe my tanks are dirty. I haven't had any fuel problems, and no crud at all in the dual Racors, no vacuum in the fuel lines, never a drop of water in the Racor bowls. I cleaned the tank 3 1/2 years ago when I installed the fuel filters and am about to do it again.

I would install a polishing system if I can do it without ripping the boat apart; if I can't then I'll have to do without. I'm at the end of a long refit and there's no money, time, or nerves for any more major projects this year.

[Dockhead]

Originally Posted by s/v Jedi

I suppose I don't need to post my diagram with the optimum plumbing again

Find the lowest point of your tank (geeks have the bubble-level app on their iPhone for this ) which must be where the new pick-up tube must end. Cut the fuel pick-up tube so that it ends 4" from the bottom of the tank. Find a piece of diesel fuel rated hose that fits over the pipe and fasten it with dual ABA hose clamps. Now insert in into the tank and measure how much too long it is. Cut the hose 2" TOO LONG. (You'll end up with about 8" of hose total length) For final fastening, tilt it a bit then work it so that the 2" hose that doesn't fit in comes to lay flat on the bottom. Like the bottom of the letter J.

Before the whacking of the Jedi starts again : this is how pro' do it. That or a bottom sump with bottom connection.

cheers,
Nick.

That sounds good, and I've filed it together with the diagram of the Platonic ideal of a fuel system, which I seem to remember also came from Jedi

[Dockhead]

Originally Posted by Navatech

On fuel polishing, yes, one way is to offload the fuel, clean the tank, polish the fuel and return it to the tank. HOWEVER, there is no way of guaranteeing that the fuel won't get contaminated again. And then you have to do it all over again.

FWIW, my setup is as follows:

I have a T valve on the fuel pickup line. It either connect the primary (engine's mechanical) fuel pump to the fuel pickup line or it connects the (electric) polishing pump to the fuel pickup line.

I have a T valve on the fuel return line. It either connect the engine's fuel return to the tank's fuel return line or it connects the (electric) polishing pump's discharge to the tank's fuel return line.

The (electric) polishing pump and fuel purifier (installed before the first T valve on the fuel pickup line) will circulate the fuel tank's entire content roughly 30 times in a 24 hour period. I will start it up one day prior to taking out the boat. If the boat isn't used I'll run the system once every two weeks for 6 hours (timer). As the fuel purifier remains in line during regular operation the fuel continues to be polished while at sea.

As a result my Racors are completely clean (even though I have the 10 micron cartridges installed) and never show any water. I replace the Racor cartridge once per year.

I decided to go this route when I bought a boat that had been on the hard for roughly 30 months in the Caribbean (humid conditions are perfect for the fuel flora & fauna). The existing fuel (about 200 gallons) was a mess! The cost (with me doing the installation) was slightly less then I was quoted for a more standard solution (with a contractor doing the work).

The tanks were about 1/3rd full. I diluted the existing fuel with an equal amount of kerosine (jet fuel), added additives that were supposed to (and, I guess, did) kill and disperse the fuel flora & fauna and ran the polisher for a week. The first day I had to purge the fuel purifier every 2 hours. The second day I had to purge the fuel purifier every 3-4 hours. The third day I had to purge the fuel purifier every 6-9 hours. The next three days the fuel purifier purges gradually came down to once every 24 hours. The last day no purge was required. I then topped up the fuel tanks with regular diesel and used the fuel subsequently. No problems at all with that mixture (old fuel, kerosine and new fuel). No problems since then.

In fact, I have since purchased several times heavily water and microbial sludge polluted diesel at 10% of the value or less, run it through my system (diluted with kerosine and with additives) and then burned it off in my engines (DD 8V92TI's). No problems and great fuel saving cost. In fact, the money so saved paid (and then some) for the system!

I'm a happy camper with my system and will install it in any subsequent boat.

Notes:

• The fuel purifier doesn't require any power (other then for the circulating pump and water level alarm), elements or chemicals. Purging is the only required maintenance. I also have a water level alarm on it. Purging is one of my items on the getting ready for sea check list.
• The fuel purifier is preceded and followed by two T valves so can be bypassed with the turning of two valves. As an added value, and depending on how I set these valves, I can use the polishing system as a fuel priming/bleeding system
• Jet fuel can be used as a fuel for the DD's without any modifications to the engines. In fact, the US Navy is now running most of its diesels (including DD's) on JP (single fuel program). Kerosine and jet fuel are essentially the same. Most if not all diesels can run a mixture of 1/3rd kerosine and 2/3rd diesel without a problem. Kerosine and diesel are quite similar in their caloric values. The main difference is in that the diesel has higher lubricative values (important for your fuel injection system).

I'm a happy camper boater

As always, YMMV!

The problem with that, as I see it, is that if your main fuel pickup is properly designed, it will be located some distance above the lowest point in the tank, so won't -- by design -- pick up water, until the water level has become disastrous.

My system already polishes fuel to the extent yours does -- the main engine fuel system is always pulling fuel through my quite good filter system and returning it to the tank.