Water Tank Vents Bavaria 44

[Jodel]

Hi,
I have a Bavaria 44.  I notice that there is a vent pipe from the forward water tank to the underside of the deck filler.  As there is no obvious vent system in the filler cap, and as it seals tightly , I am assuming that this vent only works while the filler cap is off and the tank is being filled.  Am I correct?  If so is there another vent pipe and where? How is the tank vented when the filler cap on the deck is closed tight?

Regards,
Jodel

[Craig]

Your forward tank may vent into your anchor compartment. Easy way to check is to fill your tank and see where the excess water drains out.

[Jodel]

There are only 2 pipes coming from the forward half of the tank that I can see.  One is the filler and the other is a parallel vent pipe that also connects to the filler deck fitting.
Jodel

[MarkTheBike]

Hi Jodel

Yes, we have the parallel pipe but ours runs up to the filler and then aft along the seam between the hull and deck. As Craig describes, it vents into the anchor well. I can't see it being of any use venting above deck (via the filler fitting) as that could allow seawater into the freshwater tank. If there's a spigot on the filler that the tube is attached to, can you pull the tube off, fit another tube to the spigot and blow down it to see where the air comes out?

[Jodel]

I'll try that but will not be back on the boat for a couple of weeks. 
On my boat the filler fitting has 2 connections, one for the filler pipe and one for the vent pipe.  The vent pipe one just seems to vent via slots into the top of the filler pipe section.  As you say, when the cap is closed tightly, if there was to be an opening to let air in then salt water could get in also. 
I am wondering if there is an other vent pipe from some other part of the tank (or the piping) that I can't see?
On my last boat (a Jeanneau) you could fill until water came out the filler fitting. On this boat I am finding fresh water in the bilges which seem to co-onside with trying to fully fill the tanks.  I know from other threads that there are many reasons why fresh water could leak.  However, I would like to satisfy my curiosity  as to how the tanks are vented.
I haven?t looked at the aft tank yet but that must be plumbed similarly.
I will also re-check the inspection lids , but each has a seal and I am fairly sure that they are OK
Jodel