Water tanks

[ryanwetzel]

Mike that was the perfect explanation. I think we are going to relocate the under bunk tank to under the berth in the master cabin. It doesn't make sense to remove it if we have the room. Do you think it is acceptable to then splice the vent on the "under berth" tank into the one on the transom tank?

Thanks for everyones input on this one!

[mike]

FWIW, the only experience that I can speak of WRT tank vents, is a problem with post fill siphoning; and an observation when filling tanks with a high volume of in-coming H2O that there is considerable vent pressure coming from the down stream tank vent. I would be very concerned about restricting the vent in any way due to the potential for building excess pressure, and the corresponding potential for rupturing the tank, and or a hose. Therefore, I would configure each vent with separate lines and outlets. Also, in order to prevent siphoning make sure your vent does not have any low spots, and that there is an above outlet loop. Cheers, Mike

[ryanwetzel]

So I did just as suggested running the below deck tank vent to the old under-berth tank outlet (with a loop). Filled the tanks and ended up with a bulging tank under the deck, almost an inch. I don't understand why this is the case. The pressure in the tank isn't that high from the vent.

Could this be cause I am on the hard at the moment and there is excess pressure on the keel?