Non-return valves for sink drains

JumbleDuck

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I have two sinks, one port and one starboard, which are less than a foot above the waterline and therefore backfill when the boat heels to 20o or more. Are there non-return valves which would be suitable for preventing this, or do they all need the oomph of a pump rather than a few inches of head to let stuff through? Shutting the valves isn't an intolerable burden, but I like things trouble-free and automatic.
 
i completely solved my galley sink problem by replacing the drain pipe with slightly longer one, making sure that it bent a little towards the centreline. The extra inch or two above the heeled waterline is sufficient.
 
I wouldn't use non-return valves, I think food waste might make them ineffective. If you can't be bothered to close the seacocks, and don't want to sail more upright, perhaps you might consider a sump with an electric pump in it.
 
In Kindred Spirit I fitted a manual pump to the drain, which of course incorporates two valves.

Ariam's galley sinks are properly located almost on the centreline and drain admirably, but the heads sink floods dramatically when close-hauled on the port tack. Currently we just close the seacock except when actually using it, but prompted by another thread I've realised that the better solution is one of those fancy bathroom "wastes" instead of a traditional plug. This will be much easier to lock closed without grovelling in a locker. Even if you don't want one of those in the galley for possible clogging reasons, the idea of a more easily accessible valve (perhaps operated remotely by pushrod or cable) might be worth considering?

The best automatic valve from a food waste point of view is probably the "joker" style as used in toilets (also handling food waste, in a sense :p). Whale make one in a standalone housing with hose barbs each end. Not sure how much head they need but it must be less than anything mechanical and spring-loaded.

Pete
 
I have two sinks, one port and one starboard, which are less than a foot above the waterline and therefore backfill when the boat heels to 20o or more. Are there non-return valves which would be suitable for preventing this, or do they all need the oomph of a pump rather than a few inches of head to let stuff through? Shutting the valves isn't an intolerable burden, but I like things trouble-free and automatic.
My Co32 had a manual brass pump , i removed it thinking it was pointless & discovered without it we had the same issues as you
 
All 3 sinks on Eynhallow are on the starboard side and have very little head when the boat is on an even keel, so when I bought the boat they flooded when on port tack.
I fitted mechanical non return valves to all 3.
They work, but as pvb predicts, they do get blocked, from time to time, by hair, for the heads and food waste for the galley.
A couple of pumps with a standard waste plunger, clears them, but oddly enough when they block the seem to stops the waste water flowing out, but don't let the seawater in.
The forward heads sink, which has the least head, probably less than 300mm, doesn't always drain completely, if the only a small amount of water is run into the sink, I guess this because there isn't sufficient head to overcome the pressure exerted by the spring (or weight of the flap valve, I'm not sure which) which hold the valve closed when not in use.
 
Thanks, all. I think I will experiment with a non-return valve on the heads sink. The gallery seacock as is a lot easier to get to, and I take the point about food waste.
 
I had this problem and fitted a plug with an "o" ring seal. I push in the plug and it stops the water coming back up the drain when healed. Simple, effective and will not fill up with all the hair, toothpaste and other carp that goes down vanity sinks
 
I have two sinks, one port and one starboard, which are less than a foot above the waterline and therefore backfill when the boat heels to 20o or more. Are there non-return valves which would be suitable for preventing this, or do they all need the oomph of a pump rather than a few inches of head to let stuff through? Shutting the valves isn't an intolerable burden, but I like things trouble-free and automatic.

I fitted a non-return valve to my Galley sink 14 years ago to solve just tat problem. We live on board and it is in constant use - never had a problem. The 'drop' from the sink to the seacock was so short I had trouble fitting the non-return valve into the pipework.

When we leave the boat for more than a day (overnight unattended) I close all my seacocks.
 
I had this problem and fitted a plug with an "o" ring seal. I push in the plug and it stops the water coming back up the drain when healed. Simple, effective and will not fill up with all the hair, toothpaste and other carp that goes down vanity sinks

That sounds like a good, simple idea.
There was a guy at a boat show once who was trying to flog lock in sink plugs. He was advocating them because back pressure from waves could pop the plug and you lost your hot water. He didn't have a stand, just accosted passers by. Seemed like a good idea, wish I had bought one.
 
There was a guy at a boat show once who was trying to flog lock in sink plugs. He was advocating them because back pressure from waves could pop the plug and you lost your hot water. He didn't have a stand, just accosted passers by. Seemed like a good idea, wish I had bought one.

I have that problem, as our heads sink outlet is about level with the waterline. Hence the plan to fit a bathroom-style press-down (or similar) waste. Available from any plumber's merchant, doesn't need a special boaty invention :)

Pete
 
Why not just fit a 1/4 turn valve instead of a sink plug?
One of my boats had the heads sink pumped out by the loo, controlled by a 2 way valve. It made an easy way to put chemicals through the inlet side of the loo.
 
There was a guy at a boat show once who was trying to flog lock in sink plugs. He was advocating them because back pressure from waves could pop the plug and you lost your hot water. He didn't have a stand, just accosted passers by. Seemed like a good idea, wish I had bought one.
Read more at http://www.ybw.com/forums/showthrea...ves-for-sink-drains/page2#TpwKLkb54bFcG8Wl.99

Does anyone know of something like this ? .... Such a pain when all your washing up water disappears ! Fill up the sink ... Someone calls you on deck for a mo , then you come back down and all the washing up water has gone , the plug just goes glug and pops out on a certain heel , problem being I have a sink on both sides of the boat so suffer this often either in the heads or galley ��
 
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