Design Fault?

Texel Tom · 09 May 2016, 07:01

I have just finished fitting out a new RIB and would appreciate some advice on the fuel system as I think I must be missing something. There is a built in (under deck) stainless tank with connections for the filler, breather and fuel supply hose at the aft end near the transom moulding and filler cap / breather outlet above the splash well. The issue to me is that the breather outlet is lower than the filler cap so if you fill the tank until the garage fuel pump stops then fuel will exit the breather!? Also when fuel if you park the trailer on any sort of incline again fuel gushes out of the breather?

What am I misunderstanding?

Any help would be grateful received.

matt h · 09 May 2016, 07:37

you sure the breather is not the fuel supply and vice versa?

Brian · 09 May 2016, 09:00

Or is the breather outlet meant to connect to a hose which should then rise above to the outside world?

Dry_Doc · 09 May 2016, 09:34

Quote:

Originally Posted by Brian

Or is the breather outlet meant to connect to a hose which should then rise above to the outside world?

I would suggest this too! Should be vented outside any enclosed space to prevent buildup of fuel vapour.

Nos4r2 · 09 May 2016, 09:46

Quote:

Originally Posted by Dry_Doc

I would suggest this too! Should be vented outside any enclosed space to prevent buildup of fuel vapour.

Yep.

I have something called a 'Barton fuel whistle' fitted into my breather line as well.It lets you know when the tank is full.You fit it in the breather line immediately above the fuel tank and it stops whistling when fuel gets to it.

Fuel pump cutoff will be very likely to make a mess, even with a breather higher than the filler cap.

sorabain · 09 May 2016, 10:19

Quote:

Originally Posted by Nos4r2

Yep.

I have something called a 'Barton fuel whistle' fitted into my breather line as well.It lets you know when the tank is full.You fit it in the breather line immediately above the fuel tank and it stops whistling when fuel gets to it.

Fuel pump cutoff will be very likely to make a mess, even with a breather higher than the filler cap.

Was looking those up and the picture they have on the website has the breather below the fuel port. I guess it's not such a rare thing on motor vessels in general.

Barton Marine - Products - Fuel whistle

Texel Tom · 09 May 2016, 10:58

Fantastic! Thanks for all the help and especially the suggestion of the fuel whistle. That should do exactly what I need :-) Here is a pic of the filler port and the tank vent on the far side of the splaswell...

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matt h · 09 May 2016, 13:03

you would have expected a pipe to be on it and to be dash mounted on the side somewhere surely??

Texel Tom · 09 May 2016, 14:12

Well that's my next question really. Having solved to overfilling issue
with the whistle device there is then the fact that all three connections to the tank are at the aft end in a line. This includes the breather tube which surely means when filling the tank with the bow raised there will be air in the forward part of the tank which can't be displaced?

whisper · 09 May 2016, 17:18

Quote:

Originally Posted by Texel Tom

Well that's my next question really. Having solved to overfilling issue
with the whistle device there is then the fact that all three connections to the tank are at the aft end in a line. This includes the breather tube which surely means when filling the tank with the bow raised there will be air in the forward part of the tank which can't be displaced?

You should have the breather at the front with the breather tube exiting the console at high level as Matt says

Texel Tom · 09 May 2016, 17:35

As I say 'design fault'! Tank's in, deck's down, console's in .... It's how it was sadly.

Unless they have extended to vent inside with a tube to the forward section? I'll see how much fuel I can get in....

Last Tango · 09 May 2016, 18:35

Probably not the HSE approved method of checking you've got them the right way round but if you take the filler cap off (DO NOT DO THIS WITH THE FILLER CAP IN PLACE) and, with a bit of tube blow into the fittings you'll find one blows bubbles (the lift pipe) and one doesn't (the breather.)

Xk59D · 09 May 2016, 19:16

Quote:

Originally Posted by Nos4r2

Yep.

I have something called a 'Barton fuel whistle' fitted into my breather line as well.It lets you know when the tank is full.You fit it in the breather line immediately above the fuel tank and it stops whistling when fuel gets to it.

Fuel pump cutoff will be very likely to make a mess, even with a breather higher than the filler cap.

sorry for slight hi-jack..........do these work well?

the ribcraft has a terrible design on the overflow as it throws fuel right at your face/onto pump if filling up on trailer, this would stop it if it works well?