Best way to vent a water tank?

L

Lacey.Sail

New Member
Joined
6 Sep 2020
Messages
20
Visit site
Have a sailing yacht with port/stbd tanks. The port is vented with a breather hose running up to cockpit combings. The stbd unfortunately just has the same hose going 1ft up into locker behind and it spills into bilge (as you would expect!) Is there anything out there (one way valves or similar) to save me running another breather hose through all the cupboards on that side to gain more height.

Thanks in advance
 
Thanks for that!y
Yes I did consider that but got very shallow bilges and would struggle to route the pipework under the tank and along to port side unfortunately! (n)
 
LittleSister said:
How about running the starboard tank breather through the bilge and up the port side, with a simple Y or T hose-connector to join it to the port breather tube just below its exit into the coaming?
Click to expand...

It will gurgle and snort and make all manner of annoying noises, if it's anything like mine, which has been done in a similar fashion. I'd keep the two breather separate, which i plan to do, when i get a minute.
 
Lacey.Sail said:
Have a sailing yacht with port/stbd tanks. The port is vented with a breather hose running up to cockpit combings. The stbd unfortunately just has the same hose going 1ft up into locker behind and it spills into bilge (as you would expect!) Is there anything out there (one way valves or similar) to save me running another breather hose through all the cupboards on that side to gain more height.

Thanks in advance
Click to expand...

You can't use a one way valve, the tank has to breath out when you fill it and back in as it empties.
 
I have a port and starboard tank that are positioned under the saloon seats. They are vented at a point just below where the hull meets the deck.
 
If you get it wrong you can have water overflowing when filling. Any low spots can also have water squirting out.I think the key is to slope upward with no low points.
 
PaulRainbow said:
It will gurgle and snort and make all manner of annoying noises, if it's anything like mine, which has been done in a similar fashion. I'd keep the two breather separate, which i plan to do, when i get a minute.
Click to expand...
The bow tank on my boat vents into the coaming inside the anchor locker. I unscrewed the wooden cover to get better access for cleaning and saw that the vent hose sagged down and held some water. The pipe was black for about a metre with a nice internal coating of black slime. I decided that vent pipes should really run upwards with no dips to retain stagnant water.:D:D It was fairly easy to re-route the pipe to guarantee it would always drain.

At least clean the slime was easy. I undid the hose at the tank, connected another short section tied up to the forehatch and filled it with hot strong bleach. Clean as a whistle after sitting for a few hours and procedure repeated twice with fresh water to rinse.
 
I have wondered about replacing my long, saggy (read slimey) vent hoses with a pair of automatic vents of the kind used in central heating boilers.
Not sure they would pass air quick enough though, which is why I havent done it yet.
Please try it and report back:)
 
smb said:
I have wondered about replacing my long, saggy (read slimey) vent hoses with a pair of automatic vents of the kind used in central heating boilers.
Not sure they would pass air quick enough though, which is why I havent done it yet.
Please try it and report back:)
Click to expand...
The central heating vents I've seen are designed to allow gas to vent from the system, either manually or automatically. They might be OK when filling a tank because lots of air would escape from the filler pipe anyway. The vent might help to reduce spouts of water from the filler as the tank becomes full.

How would you get water from the tank after replacing the filler? The vents I've seen aren't designed to allow air to be sucked into the system. I'm not certain why a central heating would have valves designed to suck air into the system.

What sort of automatic vents have you seen? I suppose you could fit them in the wrong direction to allow air to enter. You would then be relying on air escaping from the filler when filling the tank. A standard vent makes much more sense.
 
The ones i have in mind have an internal float valve arrangement that lets air escape up until the point the water reaches it and lifts the float. Robocal Automatic Air Bottle Vent
They will let air back through, that is how one can drain a boiler and not the heating system by closing the relevant system valves and opening the boiler drain.

I dont disagree that a standard vent makes a lot of sense, but my vents are fitted a long way from my tanks and using flexible hose its difficult maintaining the steady uphill climb through the various lockers and bulkheads, hence pooling and slime as per the op.

Still, I've been pondering on it for 20 years now and a bit of back flushed slime has not killed me yet
 
smb said:
The ones i have in mind have an internal float valve arrangement that lets air escape up until the point the water reaches it and lifts the float. Robocal Automatic Air Bottle Vent
They will let air back through, that is how one can drain a boiler and not the heating system by closing the relevant system valves and opening the boiler drain.

I dont disagree that a standard vent makes a lot of sense, but my vents are fitted a long way from my tanks and using flexible hose its difficult maintaining the steady uphill climb through the various lockers and bulkheads, hence pooling and slime as per the op.

Still, I've been pondering on it for 20 years now and a bit of back flushed slime has not killed me yet
Click to expand...
The only one I've seen had a very small vent and it operated by having a fibre seal on the top. It expanded when wet and made a seal but allowed air to pass through if it dried out due to gas build up internally. It was above a hot water tank, not a sealed central heating system.

Something with a small float valve may well work. I doubt water is pumped out quickly enough to be exceed the rate gas can enter. You can measure pump output and probably get an idea of gas flow from the spec. or dimensions of the unit.
 
You must log in or register to reply here.

Share this page

Top