Vetus Air Vent

[arronhouse]

I have just installed a Yanmar 1GM10 engine with a Vetus anti syphon device type H.
My question is :- The tell tale does not constantly squirt water. I have opened the unit and there are no parts inside to go wrong, there is plenty of water circulating the unit.
Any ideas welcome.

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[tritonofnor]

the tell tale shouldn't squirt water - it's simply a one way valve to allow air in when the engine is stopped.

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[arronhouse]

I thought that was the Vetus type V, that has a pressure valve inside it, mine has a hose connection to the outside of the hull.

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[Benbow]

Yes but its designed to allow air in not water out. I have seen installations where there is a constant stream of water out of the vent, but that is because of a bad installation with too much back-pressure.

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[snowleopard]

if the outlet is high enough to overcome back pressure from the exhaust, nothing will come out. poke a tube up the outlet and blow into it, if it's clear, stop worrying!

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[mickshep]

I have a Vetus installation on Fosca but the Exhaust is out of sight unless you hang over the pushpit, (dodgy to say the least). She has a tell tale that sends a fine jet of water out to one side where the helmsman can see it. The entire installation was fitted by a yard in Holland and having looked at the routing of the piping etc I fail to see where an excess of back pressure would originate. I was told that the tell tale was just that, now I'm confused, Cheers, Mike.

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[pete]

I also have a 1GM10, The water pump is quite small and only pumps a small amount of water (but enough) which will take the line of least resistance through the exhaust normaly, If your tell tail was at a low level water would come from it but then you would have less to cool the exhaust.
So long as it is not blocked you are ok

Pete

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[Benbow]

well the vent on the top of an anti-siphon device is not intended as a tell-tale, its job is to allow air to enter when the engine stops and the water levels collapse back, thus preveting a siphon being established.

If water is being squirted out of the vent continually, and the vent is correctly installed at the top of a loop above the waterline, then it simply means that the pump is delivering water faster than it can exit via the exhaust. That may or may not be a Bad Thing, but there should not be much to interupt the flow out. If it works and sufficient water to cool the exhaust is finding its way out, I would not worry too much.

Your engine installers obviously belong to the Microsoft school of engineering - that's not a bug its a feature !


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[mickshep]

"Your engine installers obviously belong to the Microsoft school of engineering - that's not a bug its a feature !" You got me, /forums/images/icons/laugh.gif/forums/images/icons/laugh.gif/forums/images/icons/laugh.gif. I like it! Plenty of cooling going on as ran engine for 38 hours straight from Holland to here last year without any problems.
Regards, Mike



<hr width=100% size=1>My Mum say's I'm not a fat b@st@rd, just heavy boned.

 

[RPC]

Warning re anti syphon valves:

I had a newish Yanmar with an anti syphon valve that clogged up over a short time so that the valve failed to open and the engine syphoned water into itself!

After much consultation with several engineering companies I concluded that these simple valves are not reliable and should not be entirly trusted.

Boats that have water squirting out of there anti syphon systems may be doing what I have since done on my recent engines. I no longer use proprietry anti-syphons but place a small bore pipe to discharge a constant flow so that a visible confirmation can be made that the water is circulating. This will help as an early warning to failed impellors or clogging of the intake, or pipe failure etc.

When the engine stops air is sucked back through this pipe and often a gurgle is heard.

On my first smaller yanmar this was a small pipe led into the cockpit and fed into the cockpit drain. I could hear and see the small stream of water.

In my latest 80hp Yanmar I have constructed something more sophisticated that combines this with a water lubricated shaft (a long story).
Having completed a circumnavigation with these systems I would never do anything else. This idea of using a direct bleed off is not mine, there are several references elswhere, and is often seen.

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[andyball]

Vetus do say the type H is intended to give a tell-tale flow, but as others have said, you may not get anything out if the water pressure is too low to do so.

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