Leaking vacuum valve

[Daydream believer]

Having had my first sail of the season i notice that the vacuum valve is leaking badly , yet again!!
This time 1 gallon in 30 mins
I am fed up trying to sort this. Volvo valves are renowned to failure.
I am not able to lead a hose over the side
I believe Vetus make a valve but it quite expensive, or is it?
Has anyone tried a different make . If so what was it & did it work ?
(I have even considered making a valve using a ball in a hose)

 

[markdj]

Is this the type of thing you need?
http://www.asap-supplies.com/search/anti+syphon/seaflow-exhaust-line-anti-syphon-device-410081

If it is, watch out for the hose sizes, they can be different on the input and output of the engine.

 

[VicS]

Having had my first sail of the season i notice that the vacuum valve is leaking badly , yet again!!
This time 1 gallon in 30 mins
I am fed up trying to sort this. Volvo valves are renowned to failure.
I am not able to lead a hose over the side
I believe Vetus make a valve but it quite expensive, or is it?
Has anyone tried a different make . If so what was it & did it work ?
(I have even considered making a valve using a ball in a hose)

Why not fit one that discharges a small streaminto a cockpit drain (see the alternative Vetus one)
Maybe it would be possible to remove the valve components and adapt the existing one. You might need a little restrictor in the discharge like Vetus fit.

 

[Daydream believer]

Why not fit one that discharges a small streaminto a cockpit drain (see the alternative Vetus one)
Maybe it would be possible to remove the valve components and adapt the existing one. You might need a little restrictor in the discharge like Vetus fit.

Cockpit level is above valve level plus i do not want water constantly running in cockpit in light motoring conditions

 

[scottie]

Maybe that why they tell you how to maintain them in the fitting instructions and owners books?

 

[Tranona]

The overflow on my Volvo valve goes to the watertrap/silencer. Don't know whether it leaks or not, but is always clean when I check it. On my other boat I have a Vetus one without the overflow. Seems to work fine, and easier to keep clean but expensive to buy.

 

[VicS]

Cockpit level is above valve level plus i do not want water constantly running in cockpit in light motoring conditions

It does not matter if the cockpit is above the valve.

You soon get used to water peeing but you can stick the outlet down one of the drains a little way if it affects you unduly.

 

[Daydream believer]

It does not matter if the cockpit is above the valve.

I disagree
If the pipe above the valve gets water in it & it cannot drain away immediately because it is pumping upwards then it will suck that water back first before sucking air
In the same way that you have to be careful about collecting water in a can & it sucking back if the end of the hose is below water level.
I have made a small hole in the hose above the can i collect the water in to stop this

 

[Daydream believer]

Maybe that why they tell you how to maintain them in the fitting instructions and owners books?

Not in my owners manual or my workshop manual they don't
The fitting instructions with the part consist of a picture
Perhaps you could scan a copy & wing it over please

 

[Stork_III]

Not in my owners manual or my workshop manual they don't
The fitting instructions with the part consist of a picture
Perhaps you could scan a copy & wing it over please

What engine? If MD20** series look on page 31 for valve cleaning.

 

[Playtime]

I believe Vetus make a valve but it quite expensive, or is it?

On my previous boat I got so fed-up with Volvo anti syphon that I replaced it with the Vetus valve. Had no more trouble after that.

You are right, though; the Vetus one is quite expensive now - over £90. It was just over £50 when I got mine about 10 years ago!

http://www.vetus-shop.com/vetus-anti-syphon-airvent-with-valve-13-32mm-p-517.html

 

[VicS]

It does not matter if the cockpit is above the valve.

I disagree
If the pipe above the valve gets water in it & it cannot drain away immediately because it is pumping upwards then it will suck that water back first before sucking air
In the same way that you have to be careful about collecting water in a can & it sucking back if the end of the hose is below water level.
I have made a small hole in the hose above the can i collect the water in to stop this

The hose from the vent on the antisyphon device is only a small diameter. 8mm, maybe only 6mm, in the case of the small Vetus ones.

It will only contain a small volume of water which will drain back as soon as the engine is stopped and an equivalent volume will be displaced into the exhaust system to be collected by the water trap. A metre of 8mm hose ITYWF holds only about 50cm³ of water. The antisyphon valve will then admit air and break the syphon in the cooling system.
There would only be a problem if much larger bore tubing is used, if it is incredibly long or if the water trap is so marginally sized that it cannot accept the small volume of water in the vent tube.

You do have to be careful when collecting water dribbling from the valved type of antisyphon device. If the tube goes below the waterline level it may not be able to break the syphon in the cooling system and could in fact continue to syphon water into the boat! Also if the tube dips deeply into a large volume of water as that could flood the exhaust system when it is sucked back