Vetus Airvent for exhaust cooling water

[trashpad]

Hello All,

I just had my old Nani's replaced with new Betas. They ended up installing Vetus Airvent V. My question is they did not attach a small tube from the top barb. Should they have?

Not much info on the web about valve vs. no valve so not sure.

[BillKny]

I hate these valves when they are mounted in an engine room. Not Vetus in particular, but all of them.

There is a little rubber joker valve that allows air IN to break a syphon, and keeps water IN to avoid making a mess. The problem is sometimes they clog with salt, and don't let air in and your engine drowns, or they stick open and spray salt water all over your engine room. Even the most persnickety maintenance programs frequently miss them.

The reason for attaching a hose to the nipple is to send the salt water to a safer place when the little valve fails--usually to the bilge. It is vital that the hose used can NEVER have its end in standing water, and should always be free draining. Violating either of those conditions would disable the syphon break function.

It's optional to attach a hose there, until you wish you had.

The RIGHT way to rig a syphon break is to avoid the fussy little one-way valve, and just have a small hose go from the high point of the gooseneck to somewhere the flow can be observed from the helm. That way you can see that you have water flow and you know you have a working raw water pump, and syphon break.