A few more questions with tank install....

[Crinan12]

Hi

I need to buy an 8mm threaded hose connector for the fuel pick up on my new tank (the supplied one is 10 mm and I need to use 8mm hoses). Do these connectors need a washer or anything to seal the air or can I just screw it straight on? The supplied one doesn't have a washer. Just some blue greasy stuff round the thread.

Also about the vent pipe connection- my existing tank had a vent pipe going from the tank and out through the transom . Is this pipe necessary or can it just be vented via the fitting with no pipe at all?

Thirdly. My previous tank had an on/off tap on the supply hose. I wasn't going to bother with one this time. I thought it might be just another place for air to get in. Is this a bad idea ?
Thanks

 

[Skipper_Christoph]

The vent should be connected to a pipe going to the outside air. You don't want to have petrol fumes in the boat.

 

[lw395]

The vent must be a long pipe led high up, other wise you may lose fuel through it when it surges in choppy waters.
You may get fuel out of the vent when filling the tank, if the vent is poorly done.
Even diesel will stink the boat out, so the vent needs to be 'outdoors'.
Transom is best.
Vent should be big enough to let all the air out as you fill the tank, otherwise the tank may/will belch diesel out of the filler.
Some people have a big vent they open when filling.

It's a very good idea to have a stop tap at the tank. If a hose fails, fuel may otherwise syphon out.
In the event of an engine fire, you'll want to turn this tap off.
Changing filters, there may be less bleeding if you turn this tap off.
In your case, you could have the tap elsewhere, outside the engine box and accessible, preferably from on deck, e.g. in a cockpit locker?
I think some regs say have it on the tank (?????), but I am not up to speed with chapter and verse.

 

[Crinan12]

Of course. The fuel would spill everywhere without the pipe. I didn't actually think of that believe it or not !

If I fill via jerry cans can I blank the vent connection off and just leave the wee screw thing open on the filler cap? Like an outboard ?

I'll fit a tap

And does anyone know how you seal the threads on the connections to the tank so they are airtight ?
Thanks

 

[fras]

I had a new tank made last year with new hose runs throughout. I was recommended to seal the hose fitting threads with Loctite 577. Not cheap but worked a treat.