VETUS ANTI SYPHON LEAK QUESTION

[vsergio]

The drain line on the vetus anti syphon device drips water when the engine (Yanmar 3gm30F) is running at 2000 rpms or more. The drain line drops down from the device bellow the Volvo stuffing box and shaft.


I understand the purpose of the device but not sure if at high rpms the drain line is supposed to leak water in the bilge? I opened the vetus device and found no salt or any other impurities around the valve spring and seals. I cleaned it anyway and after installing back, nothing has changed.

Any help/suggestions would be greatly appreciated.
Thank you

[vasko]

I changed my antisyphon device with a simple 3 way connection and passed the drop hose( smallest pipe) high up ( max possible)  and next down and with another 3 way to my eliche-radice  dripless seal and out of the hull  - this way I have proper antisyphon and also use the surplus to cool the dripless seal. 

now to your question - the antisyphon device should not drip...   I has a s similar issue in one of my previouse boats and in the end got frustrated and exchanged the antishyphon device with simple connector ( was in the middle of a trip and did not have from where to buy a new device) - e.g. no more antisyphon and sailed 5 years to the point when I sold the boat.. and as far I know the boat is still going good... 

[vsergio]

Thank you Vasko. It seems to me that the drain line is more active now since I cleaned the mixing elbow. If you recall, the vetus device has a valve that is closed by a very fine weak SS spring. To push open the valve and defeat the spring tension, a positive pressure must be created by the water flow. Since cleaning the mixing elbow, I assume that more water is free to travel from the engine to the mixing elbow and as such the pressure in the vetus should be lower?!

Am I wrong? 

[vasko]

Logically thinking yes, but the main blocker usually is something in the heat exchanger, but actually in your case my vote is that everything is good - just your vetus device may have become old or not correctly designed or wrong model for your exact engine...

the best antisyphon strategy ( as far as I can tell) is the design that I'm using - a lot simpler and do not relay on any springs etc.   My experience with the antisyphone devices is that they are prone to fail in some point ... 


www.betamarinenc.com/exhaust-design/

I just use a T-piece without any vacuum breaker and all is good...

[Allegria]

Hello,

I had a failed anti-siphon valve on my 2010 SO36i and it took me a while to discover the issue. The water line would empty itself when I stop the engine. Hence, I was never next to it to witness it, just found some water in the bilge.
Although it wasn't leaking when running. So it might be different from yours.
Anyway, once I replaced the part, my engine bilge became dry again...

Not an expensive part, for once, and dead easy to change yourself...

Cheers,
Allegria

[boltnbrew]

I had the same experience as Allegra- replace and the bilge was dry afterward. That was 10 years ago.