Non-return valve on sink drain

[Halo]

I had a problem with water coming up into the vanity sink ( I know I should not over canvas and have her healed right over but S**T happens when its gusty) . I made a new plug hole assembly and a new plug with an O ring. This works beautifully - just push it in and the slight water pressure is easily held back by the plug. I will post photos is anyone interested
Martin

 

[jerrytug]

On my Twister the top of galley sink is not much above the waterline and the bottom is probably below it. There's no problem with back-flooding because the sink is emptied with an old brass Whale pump that has a non-return valve built in.

Same as mine, works well.

 

[aquaplane]

I'm a great believer in doing things that actually need doing.

Either shut the valve that lets the water in, or live with it. It's not really a problem unless you forget, don't forget.

 

[dunedin]

I'm a great believer in doing things that actually need doing.

Seawater entering the cabin when underway would seem high on the list of important things to prevent, to my mind

This is something we have found as a surprising issue with our boat - interested in any solutions, such as the o-ring sink plug suggestion

 

[aquaplane]

Seawater entering the cabin when underway would seem high on the list of important things to prevent, to my mind

I agree that keeping the water on the outside is a good target. Adding an engineering solution which can go wrong isn't a good way of solving the problem.

Remembering to shut the sea cock is a no cost simple solution, so long as you remember.

A presailing checklist, or a mod to the existing one, would be my solution.

 

[Deleted member 36384]

I agree that keeping the water on the outside is a good target. Adding an engineering solution which can go wrong isn't a good way of solving the problem.

Remembering to shut the sea cock is a no cost simple solution, so long as you remember.

A presailing checklist, or a mod to the existing one, would be my solution.

Bob, an engineering solution is far better that a procedural solution (check list). In Safety Engineering hazard control the following is an order to managing risks from good to bad: -

Elimination
Substitution
Engineering
Administration
Personal protective equipment

The first would be to have no seacock and use the bucket and chuck it solution; the second could be use a bucket in the cockpit to wash up stuff; the 3rd is the NRV solution, 4th is the check list, and 5th is wearing a lifejacket in the hope that if the boat sinks at least you will float away. The order has been arrived at after years of failure analysis. Basically you can't trust a human so administrative methods are not considered efficient at reducing risk, as the OP demonstrates.

Assuming that rptb1 wants a sink with an overboard drain, then the NRV is the safest solution. All in my and my HSSE colleagues humble opinion of course.

 

[geem]

Bob, an engineering solution is far better that a procedural solution (check list). In Safety Engineering hazard control the following is an order to managing risks from good to bad: -

Elimination
Substitution
Engineering
Administration
Personal protective equipment

The first would be to have no seacock and use the bucket and chuck it solution; the second could be use a bucket in the cockpit to wash up stuff; the 3rd is the NRV solution, 4th is the check list, and 5th is wearing a lifejacket in the hope that if the boat sinks at least you will float away. The order has been arrived at after years of failure analysis. Basically you can't trust a human so administrative methods are not considered efficient at reducing risk, as the OP demonstrates.

Assuming that rptb1 wants a sink with an overboard drain, then the NRV is the safest solution. All in my and my HSSE colleagues humble opinion of course.

My experience with NRVs is they work well when you apply pump pressure through them. Gravity outlet from a sink could be a problem as things like long hair have a habit of sticking in the NRV. A pump tends to blast hairs straight through such as on a Jabsco loo. If you get a small build up of hairpin a wash hand basin, the NRV leaks and you slowly fill the sink with sea water. We tried the NRV a few years ago and eventually removed it. We then went to the pop up sink waste. You still need to remember to push it down but we don't have to empty the locker under the wash hand basin to get tot the seacock.

 

[aquaplane]

Bob, an engineering solution is far better that a procedural solution (check list). In Safety Engineering hazard control the following is an order to managing risks from good to bad: -

Elimination
Substitution
Engineering
Administration
Personal protective equipment

The first would be to have no seacock and use the bucket and chuck it solution; the second could be use a bucket in the cockpit to wash up stuff; the 3rd is the NRV solution, 4th is the check list, and 5th is wearing a lifejacket in the hope that if the boat sinks at least you will float away. The order has been arrived at after years of failure analysis. Basically you can't trust a human so administrative methods are not considered efficient at reducing risk, as the OP demonstrates.

Assuming that rptb1 wants a sink with an overboard drain, then the NRV is the safest solution. All in my and my HSSE colleagues humble opinion of course.

I agree with all you are saying.

Our Centaur galley sink sometimes needs a helping hand to get the flow going, a NRV would not help.

Along with the probability of the thing sticking open or passing I think a NRV is a non starter.

So, remember to shut the seacock is still the best solution for me. Other folk can do what they think best and I will too.