Is There Another Way to Install a Fuel Pump? (Gasoline/Petrol)

[Scubaseas]

Originally Posted by Chotu

Ha ha ha. Yes, pressurized fuel in my hulls is a non starter. Way too risky.

150 gallons of gasoline leaking out into the bilge is a life threatening event.

What does ABYC suggest? Anyone have this chapter?

Man, I hate the idea of a day tank. I understand why it’s a good idea, I just don’t want to make more space for fuel when it’s already in a tank.

Maybe I can shave every inch of rise off the fuel supply line and put the pump at the very bottom of the “explosives box” which isn’t too far above the top of the tanks.

You need ABYC H24 for gasoline tanks. I have H33 which is for diesel which says no way on pressurized tanks.

So use a lift pump. Ask Facet if a Duralift will work for you.

[thinwater]

You can avoid pressurized lines from the explosives box to the engine by installing a pressure-demand valve in your explosives tank. Attwood and others. This is a common way to avoid the pressurized line problem, ever since control of fugitive emissions became a thing. Any installer or boat builder would know this. Many outboards use them.


There is no avoiding some amount of push (pressure) from the tanks to the box. The laws of nature say so. Adding a day tank only increases the number of things that can go wrong IMO.


A Raycor is a complete waste of time for e10 gasoline. Water does not separate (unless the tank separates and that is fatal), so the design only increases the potential for leaks. Better to chose a small in-line filter. Gasoline does NOT require the same filter volume as diesel because it does not grow bug or precipitate asphaltenes. I would simplify the fuel train and skip the box, which would eliminate the need for the auxiliary pump. I believe, well maintained, it is safer. There are reasons no one ever used your approach, and there have been inboards forever. In other words, use proven methods. I believe the explosives box concept, in this cases, reduces safety by adding failure points.

[boatpoker]

Originally Posted by Chotu

Ha ha ha. Yes, pressurized fuel in my hulls is a non starter. Way too risky.

150 gallons of gasoline leaking out into the bilge is a life threatening event.

What does ABYC suggest? Anyone have this chapter?

Man, I hate the idea of a day tank. I understand why it’s a good idea, I just don’t want to make more space for fuel when it’s already in a tank.

Maybe I can shave every inch of rise off the fuel supply line and put the pump at the very bottom of the “explosives box” which isn’t too far above the top of the tanks.

PM me an email address and I'll respond with the ABYC Standard

[Compass790]

Originally Posted by Chotu

A few concerns with this approach:

1) pressurized gasoline fuel lines in my boat.

2) how do I change the fuel pump when it goes bad?

3) I have to buy 3 pumps?

4) how do I install these given it’s a poly tank that’s all polypropylene welded everywhere?

1) you get a pressure reducing valve


2) Mount it on a removable flange.


3) Yes a problem but they aren't that expensive


4) Ummm, assumed it was stainless, shouldnt have assumed.
Should still be doable but might be a better way around the problem.

[AKA-None]

So tell me the practical difference between push air into a tank to push fuel up to a pump and putting a fuel pump in the tank. Doesn’t that still mean the fuel lines are pressurized?

[Chotu]

Originally Posted by AKA-None

So tell me the practical difference between push air into a tank to push fuel up to a pump and putting a fuel pump in the tank. Doesn’t that still mean the fuel lines are pressurized?

I’d say there are 2 main differences.

1) entire fuel tank would be pressurized and worse, be cycled with pressure every time you turn the engines on and off.

2) when filling the tanks, the breather won’t work right with a fish pump hooked up to it.

[Chotu]

Originally Posted by thinwater

You can avoid pressurized lines from the explosives box to the engine by installing a pressure-demand valve in your explosives tank. Attwood and others. This is a common way to avoid the pressurized line problem, ever since control of fugitive emissions became a thing. Any installer or boat builder would know this. Many outboards use them.


There is no avoiding some amount of push (pressure) from the tanks to the box. The laws of nature say so. Adding a day tank only increases the number of things that can go wrong IMO.


A Raycor is a complete waste of time for e10 gasoline. Water does not separate (unless the tank separates and that is fatal), so the design only increases the potential for leaks. Better to chose a small in-line filter. Gasoline does NOT require the same filter volume as diesel because it does not grow bug or precipitate asphaltenes. I would simplify the fuel train and skip the box, which would eliminate the need for the auxiliary pump. I believe, well maintained, it is safer. There are reasons no one ever used your approach, and there have been inboards forever. In other words, use proven methods. I believe the explosives box concept, in this cases, reduces safety by adding failure points.

Yes, it’s tough to use the proven methods because I’m familiar, as most people who sail are, with diesel installations. Most specifically Yanmar and Perkins engines.

Outboards are an entirely new beast for me. Inboard gasoline fuel systems even more so.

I treated the gasoline like propane because I don’t know any better.

I made it so there are no connections inside the boat. Just like propane. The T’s, valves, pump, etc. anything that can leak, are all in the explosives box, as are the same type of connections for the propane system and propane tanks too.

Very safe, but maybe not great because of the reasons you mentioned.

I do have pressurized fuel from the explosives box to the motors, but no junctions in the fuel lines, so it doesn’t concern me at all. Like a propane install.

I’ll take a look at all these thoughts

[Chotu]

@thinwater

I use non ethanol gasoline, but it’s getting harder to find. I know up north I couldn’t find it dockside one New York this summer.

Currently the fuel goes tanks > 3 hoses > explosives box > ball valve tank selector manifold > Racor > fuel pump > (now pressurized) to manifold to branch out to 2 fuel injected outboards and 2 carbureted generators.

How would you change that fuel system to follow your advice?

[boatpoker]

Originally Posted by AKA-None

So tell me the practical difference between push air into a tank to push fuel up to a pump and putting a fuel pump in the tank. Doesn’t that still mean the fuel lines are pressurized?

mmmmh ... A pressurized fuel tank without a vent.
Think they call that a bomb.

[Chotu]

In reviewing some ABYC requirements (thanks BoatPoker), I see one I can’t meet at all.

“ 24.15.7 If used, electric fuel pumps shall be independently supported and located within 12 inches (305 mm) of the engine with a maximum delivery hose length of 48 inches (1.22 m).”

I’m assuming there is an exception for outboards and larger boats that I’m missing?


I mean it’s a logical impossibility for my fuel pump to be near both engines at the same time. They are almost 25 feet apart!

[AKA-None]

Originally Posted by Chotu

I’d say there are 2 main differences.



1) entire fuel tank would be pressurized and worse, be cycled with pressure every time you turn the engines on and off.



2) when filling the tanks, the breather won’t work right with a fish pump hooked up to it.

So then that obviously is worse than a pump in or near a tank pushing fuel to the engines

[Chotu]

Originally Posted by AKA-None

So then that obviously is worse than a pump in or near a tank pushing fuel to the engines

Much worse.

[Scubaseas]

I wonder how long it would take an aquarium filter to pressurize a 30 gallon fuel tank to .6psi when the tank is 1/4 full?

“ 24.15.7 If used, electric fuel pumps shall be independently supported and located within 12 inches (305 mm) of the engine with a maximum delivery hose length of 48 inches (1.22 m).”

So put one lift pump on each engine within 12" of the engine with a maximum delivery hose of 48". Is there a engine well or push transom/bulkhead? Maybe make you drain box on that member and put a pump inside it? Or put a transfer pump in for a day tank that's less than 24" dry head of the motors.

[Chotu]

Originally Posted by Scubaseas

I wonder how long it would take an aquarium filter to pressurize a 30 gallon fuel tank to .6psi when the tank is 1/4 full?

So put one lift pump on each engine within 12" of the engine with a maximum delivery hose of 48". Is there a engine well or push transom/bulkhead? Maybe make you drain box on that member and put a pump inside it? Or put a transfer pump in for a day tank that's less than 24" dry head of the motors.

That would make everything that I started the thread about significantly worse. If you put a lift pump at every device, that’s four lift pumps. And each of them would have to have a significantly higher lift than the current one. The length of the tubing before the lift pump would also be 4 to 10 times longer depending on the device.

I think your original post in this thread with the long paragraphs and complete details of how to change the system around is probably a much better idea than this one. This is where ABYC goes out the window because it doesn’t apply. I guess they can’t take every boat configuration into account when they make the rules.

[Scubaseas]

Originally Posted by Chotu

That would make everything that I started the thread about significantly worse. If you put a lift pump at every device, that’s four lift pumps. And each of them would have to have a significantly higher lift than the current one. The length of the tubing before the lift pump would also be 4 to 10 times longer depending on the device.

I think your original post in this thread with the long paragraphs and complete details of how to change the system around is probably a much better idea than this one. This is where ABYC goes out the window because it doesn’t apply. I guess they can’t take every boat configuration into account when they make the rules.

Personally I don't think standards change to fit the circumstance or for convenience. Your boat, your call but standards are standards. You meet them or not. Do or do not as Yoda said.

You have 2 devices other than the two outboards? One lift pump per outboard solves the day tank issue and keeps ABYC happy and no pressurized lines in the boat. Not good? Don't do it.

Is your generator also gas and also above 60" dry lift? And what else that eats gasoline? Sorry I have no idea what you have or where it is. Clueless actually.

So put a day tank in with a pusher transfer pump. Transfer pumps can go anywhere as far as ABYC is concerned. A day tank is pretty uncomplicated as all you need is one transfer pump and some valves, a vent and a fill hose if you want it. Plus a fuel level indicator and shut off system for unmonitored filling of the tank. Or manually flip the transfer pump on/off. Day tank is certainly less complicated than multiple pumps and piping. Or just put a day tank in and fill it with a bucket as needed which would save weight and be as reliable as the person with the bucket can be.