Fuel Tank questions

[prv]

My Nanni engine data sheet states 8mm for the fuel feed but it doesn't say what the fittings are

Almost certainly hose barbs, as the connection to the engine needs to be flexible. Achieving that flexibility with a coil of polished copper pipe looks very nice in a narrowboat or steam launch, but is unlikely to be what Nanni have in mind

What you should have on the tank depends on what you're planning to fit between tank and engine. Personally I prefer hose everywhere, as I reckon quality reinforced hose is actually probably stronger than thin-walled copper tubing. But some people worry about the hose burning through in a fire, or believe that metal is automatically more robust, and run copper from the tank to a point just next to the engine, bridging the gap with a short length of hose. You won't be running a single continuous length from tank to engine anyway, as the primary filter needs to go in between, and preferably a stop tap too. If the tank is in the engine space, there is perhaps an argument for copper from the tank to a nearby valve, to be closed in case of fire, and hose after that. I've inherited valves mounted directly on the tank banjos, with hoses thereafter, and I plan to eventually make the valves cable-operated from an "emergency fuel cut-off" pull-handle outside the engine box.

Pete

 

[sailorman]

My Nanni engine data sheet states 8mm for the fuel feed but it doesn't say what the fittings are, can I go ahead and buy compression fittings for the tank or will there be trouble if the engine has hose tail types ? Anyone know what the Nanni N.38 fuel feed fitting type is ?

Thanks to all who have replied,

Boo2

Pop along to your local Pirtec depot, they will have all you need. including fire rated rubber hose.

 

[Boo2]

Pic of tank

Hi,

After all the help and advice I received I thought I'd post the final tank design. As you see I dropped the idea of catering for an auxiliary tank in addition, hopefully 47 gal should suffice. Drawn using Alibre.

<Edit: Added .pdf hopefully in a readable scale>

Boo2



View attachment sunrunner_fuel_tank_130315_001.pdf

 

[prv]

After all the help and advice I received I thought I'd post the final tank design.

Perhaps it's just the small scale of the picture, but I can't see anything (either a dip tube from the top or a tap at the bottom) that will access the deepest part of your tank. Is that deliberate? Seems like a poor design to me, if so.

Pete

 

[macd]

Perhaps it's just the small scale of the picture, but I can't see anything (either a dip tube from the top or a tap at the bottom) that will access the deepest part of your tank. Is that deliberate? Seems like a poor design to me, if so.

I believe you're right. If I remember correctly from installing one, the standard inspection cover/hose plate has the usual filler/feed/return/breather fittings but no facility for a drain, which to my mind is not best practice (and surprisingly so given their reputation and experience). No doubt they can add a dip tube, or anything else if asked, but it seems not to be standard.

 

[Boo2]

Perhaps it's just the small scale of the picture, but I can't see anything (either a dip tube from the top or a tap at the bottom) that will access the deepest part of your tank. Is that deliberate? Seems like a poor design to me, if so.

Hi,

Yes, it's just the small scale - I've added a .pdf which will hopefully make more sense. The dip tubes aren't drawn but the feed and drain both have them going to the deepest part of the tank, the drawing notes refer.

Thanks to all who posted on this thread,

Boo2

 

[prv]

The dip tubes aren't drawn but the feed and drain both have them going to the deepest part of the tank, the drawing notes refer.

Hmm. What I meant was that there are no fittings mounted above the deepest part, so cannot be vertical dip tubes reaching into it. You seem to be planning cranked dip tubes with two bends in - have you discussed this with Tek? I've not come across such a thing before.

Pete

 

[Boo2]

Hmm. What I meant was that there are no fittings mounted above the deepest part, so cannot be vertical dip tubes reaching into it. You seem to be planning cranked dip tubes with two bends in - have you discussed this with Tek? I've not come across such a thing before.

Hi,

Yes, TT were OK with the dip tubes going in on a slant. I can't think of any reason not to do that, it's only 10mm copper pipe so I wouldn't expect any problems doing that. It's the only way to get ready access to the hose tails and have all connections on top of the tank, so I think it's reasonable to do it this way.

Boo2

 

[NormanS]

Hi,

Yes, TT were OK with the dip tubes going in on a slant. I can't think of any reason not to do that, it's only 10mm copper pipe so I wouldn't expect any problems doing that. It's the only way to get ready access to the hose tails and have all connections on top of the tank, so I think it's reasonable to do it this way.

Boo2

You haven't made it clear, but I hope you intend to have the drain pipe going substantially lower into the bottom of the tank, than the feed pipe.

 

[prv]

Yes, TT were OK with the dip tubes going in on a slant. I can't think of any reason not to do that

Fair enough, then. From some of your earlier replies it sounded like you hadn't actually made contact with them yet. I can't think of any reason not to have angled dip tubes, just that I've never seen it before. Usually they're vertical with the fittings mounted above the deepest part of the tank, but obviously that wasn't an option in your case. Looks like a pukka job.

Pete