Water leaking out of antisiphon valve

[firstascent2002]

Hi guys,

The antisyphon valve on my volvo 2002 has a small bit of rubber piping attatched to the top of it which leads out of a lockerside and into a cockpit drain. I noticed a steady drip drip of water out of it today for the first time. May have always been like that but it is the first time I've noticed it. Any thoughts. Good, bad or indifferent!

 

[Hoolie]

Depends on what kind of syphon valve you've got. Our previous one was a small neoprene disc - as naff as it sounds - that failed and filled the engine with sea water /forums/images/graemlins/confused.gif It's now sorted and I've replaced the anti-syphon with a much more professional item from Norris in Teddington. Check it out before it fails!!!

 

[Spuddy]

Seen similar arrangement where the tube you mention acts as a tell tale - shows impeller OK and inlet not blocked so cooling system working. Could have some sort of tap to stop too much water being diverted from exhaust cooling duties. Version I saw had a SS sqeezy thing from an operating theatre. Or outlet on top of antisyphon valve is part blocked.

 

[Dipper]

The one on my Volvo 2001 always drips even when a new service 'kit' has been fitted. I think this is a characteristic of the Volvo version. I keep meaning to extend the tube and catch the drips in a bottle but I have never got round to it.

 

[VicS]

The Volvo valve has a valve in it which should normally be closed only opening to allow air in to break the syphon when the engine is stopped.

They require periodic maintenance/overhaul but even then often leak water sightly while the engine is running.

There are types which do not have a valve and are designed to discharge a small water stream to a drain or overboard all the while the engine is running. A bit like the "pee stream" from an outboard engine. Vetus offer both types, identical in external appearance

At least while it is discharging water you know it is not blocked and will allow air in when the engine is stopped.

 

[charles_reed]

2 Types of anti syphon valve.

1. a chamber with 3 pipes in-out - always, pumps water, like an OB telltale, one inlet from raw-water pump, outlet to exhaust-elbow, smallest overboard. Probably the best, certainly simplest.

2. an inverted U-tube with a spring-loaded to open valve. Closed by the water pressure to the exhaust elbow.

If the 2nd, unscrew the top and replace the O-ring. If the 1st - well Ure pretty unobservant

 

[ShipsWoofy]

Mine dribble (as they should) while the engine is running, I have Vetus ASV fitted.

 

[Foxy]

I have same issue with the vetus non dribble, dribbling. In rough weather It dribbles out of the vent pipe, which unfortunately isnt stopped by changing the o-ring. Occasionally you can rectify it by taking the thing apart and giving it a little tap, but it doesnt work for long. I'm looking to replace mine as recently, the water dripped down the outside of the water hose and onto the pulley at the bottom of the engine. This ended up with a tiny spot of rust on it,, which in turn made me wear through two v belts in a matter of weeks! Took ages to find the cause as it was so small. Worried that one day the valve on the vetus wont open either - not pretty.

 

[ShipsWoofy]

Mine are not an issue, they are designed to dribble and I have the breathers exiting the hulls alongside the exhaust through-hull.

 

[30boat]

I made my own anti syphon thinghie with a stainless tube bent in a U shape and with a stub on the top for a pipe wich goes to the stern.When the engine is running it always dribbles wich tells me two things: that the raw water is circulating and it's temperature.When I had a water filter mounted too high wich prevented it from filling up ,I could tell the water was too hot without the alarm going off and when ,on another occasion,the alarm was going off all the time I new it was faulty becase the water was still lukewarm.
It's main function is ,of course, to break the vacuum in the hose when the engine is stopped.