Water tank vent

jammin · **Joined:** 30 Oct 2006 15:40 **Posts:** 63

Has anyone else had trouble with the port water tank draining it's contents out through the vent tube? Several times we have been on a starboard tack and found the bilge full of fresh water and a partially empty port tank. (OK, maybe we should reef a little.) As near as I can tell the vent loop on the port tank is below the water line when heeling, and starting with full tanks will result in the water siphoning out through the vent.

(We also found that you must open the valve only on one tank at a time. With both valves open the water in the high tank drains into the lower tank with the same result. We only did this once, close hauled in 25-30 knots.)

I am now planning to replace the vent line with a vent located higher. We'll see how this works.

Jerry
JAMMIN' #226

Tortuga's Lie · **Joined:** 27 Oct 2006 10:32 **Posts:** 827

Does your boat also only have one water fill deck fitting? I think early Tartans figure that they could fill both tanks at the same time with only one fitting, but what happens is that the starboard tank over-fills as the port tank slowly fills. This happened to me once and the water was forced out through the vent hose. I now fill the tanks through the inspection caps. I will one day, add another deck fitting........low on the priority list.

jvoelxen · **Joined:** 21 Oct 2006 15:36 **Posts:** 268

I had a similar problem with my starboard FW Tank. Before leaving for weekends I would fill both water tanks. At the end of the weekend both tanks would be close to empty, although I used very little water during the weekend. Both tanks were cross-connected. When I filled the tanks and checked for leaks while on the mooring, both tanks held fine. There way always water in the bilge, but I have a float activated bilge pump, so I never new how much water may have leaked into the bilge.

Anyway, to make a long story short, I found the the starboard water tank had a crack on the top. It held water well when the boat was on the level, but while heeling the tank would leak. I had the tank crack plastic welded and it holds well now.

Now, I never cross-connect the tanks. I'm also very careful while filling the tanks. In the past I would leave the hose in the fill connection until it overflowed. That 4-5 feet of head from the fill connection puts about 2-2.5 psi pressure on the tank, which I believe caused mine to 'explode.' Now I only fill the tanks to the top as viewed from the inspection ports.

Jim
Odessey #191

jammin · **Joined:** 30 Oct 2006 15:40 **Posts:** 63

We have dual fill ports on deck. We do have the ability to cross-connect the tanks through the valving, but have learned to keep one tank closed off due to the bad effects of heeling.

I just did an accidental pressure test on the port tank when checking the new vent line. The vent works fine until the tank tops out, then ooomph! Didn't know the tank could buldge like that. Drained some water out and now it is OK. Don't want to damage it days before a cruise.

Something to consider if you are adding a port fill fitting. The routing of the port fill line is awful. It must take over 30' of 1 1/2" tubing, down the stbd locker, through the water pressure pump locker, down the bilge almost to the chart table, up through the settee locker, across and into the tank fill port. Can't think of anyway else to do it right now. If your present system works, then it may not be worth the trouble to add a new fill.

Jerry
JAMMIN #226

cseltz · **Joined:** 14 Nov 2006 07:50 **Posts:** 3

This looks like a pretty old thread but... No one I know with a T-37 fills the water tanks from the deck fill. We all take the hose below and fill from the tank ports.

Tartan37.com

Water tank vent

Who is online