vetus anti syphon valve ~ problem?

[DogWatch]

I have these fitted to my engines

We were motoring on Tuesday and I happened to notice the port engine valve had water pouring from the pipe attached to the top of the valve. When I say pouring, I mean coming out of the outlet on the side of the boat. The starboard engine was only spitting as it always has. This pouring is new to me, but I must admit it was only by chance I noticed it, so it may not have changed at all.

When I dropped the revs, the outlet went back to spitting. I was running the engine a little harder than I normally do, approx 2900rpm. The exhaust was still running wet, I did not notice a lack of water, though having a stream of water leaving through the A-S-V would surely indicate a lack of water at the exhaust.

Is this a faulty valve? (by christ the price has gone up since I bought mine)

Can these valves be serviced?

As it appears to run normally in all other aspects, should I just monitor and ignore?

and finally, is the valve directional? I can't get to the valve myself so asked No.1 crew to feel/look for some kind of directional arrow, she couldn't find any markings on the valve. When this engine was put back a couple of years ago after some work there was a change, if left for any period the exhaust was starting dry, it now takes a few seconds to fill with water, not long enough to cause a worry. I had also moved the water inlet filter and changed pipe-work, so put it down to that, but could the engineer have put the A-S-V back to front (though I don't know how as I think due to my fitting this would have crossed the pipes).

Thoughts?

EDIT>> for clarity, under the waterline 1GM10, water filter just above the water line, vetus anti-syphon valve, vetus water lock, gooseneck (made with exhaust hose not dedicated device) approx 12" above exhaust outlet, exhaust approx 3" above water during normal operation.

 

[smeaks]

there are two types pf these. one has a non return valve monted in the cap that shuts when the device is pressurised. when the ngine stops puming water the valve opens allowing the water to run out of the engine being replaced by air drawn through the small bore pipe on top. These can stick if salted up resulting in either no air flowing in (hence negating the function) or water coming out when pressurised. the other sort has no valve and the small pipe is vented OB and acts a tell tale that the coolant pump is presurising the system. If yours has always done this and is piped then it is probably one of the latter. If it did not do it and now does then the valve is stuck open and not seating. You can remove the cap and flush out with hot water. this usually frees everything up.

If it is discharging OB I do not think it will be a problem and you can be reassured that when shut down the siphon loop is deffinetly broken.

 

[alahol2]

I have one of hese anti-syphon vents, the type without a valve. When on tickover I only get a few 'spits' from the vent pipe. As the revs increase I get proportionately more water from the vent until, at full revs, it is creating a 2 foot continuous stream. I would say your port A-S-V is working correctly, possibly the starboard one has a problem (kinked outlet hose?).
So far as I am aware the vent is not directional, I actually read the instructions when installing it and I would have remembered something like that.

 

[VicS]

If your valves are connected to a skin fitting I would expect them to be the type without a valve and therefore I'd expect to see a continuous discharge stream from them.

It is possible of course that the valved types have been connected to a skin fitting. That I feel would be a bad thing to do. With no constant water stream it would be all too easy for the pipe to become blocked and then no air would enter to break the syphon when the engine is stopped.

I would look at the height of the water injection point into the exhaust system relative to the water level.
If the injection point is well above ( several inches or more ) then there is no panic.

If it is close to the water line or below you should investigate ASAP
If they are the valved type, clean the valves. I would also disconnected the discharge pipe, or remove the valves.
If they are of the non valved type then clean the the pipework through and get them both peeing over board.

They are not directional.

The valved type should be regularly cleaned.
If the non valved types stop peeing the reason should be determined and rectified.

Diagrams can be found in the Vetus on line catalogue http://viewer.zmags.com/publication/fd2b8fee#/fd2b8fee/1

but simpler and of the old type like yours

 

[DogWatch]

They are definitely the non valve type, I bought and fitted them.

My question arose as from new they have only displayed a spitting output, the jet of water is either new or just unnoticed previously.

EDIT>> A picture tells a thousand words

 

[wizard]

I have the same valve on my Yanmar 2gm. The full flow from the antisiphon is perfectly normal - in fact I routed my outlet in order to view it from the helm position to check at a glance that there is nothing stopping the raw water entering the engine. If it flows like you say then the antisiphon is working.

 

[DogWatch]

Thank you all, it seems this is normal and nothing to be concerned over.

Exactly the response I was hoping for.