PVC gate valve doesn't seem to close

[eugenesdream24]

In my head under the sink I have a Braham 1" PVC gate valve that is a waste drain out. I removed the tube that runs from the sink drain to the valve and as the boat rocks water spills in. No matter which way I turn and tighten the valve this happens. So I put the tube back on and the water does not come all the way up. So I figured its just below the waterline and water won't come in with this tube on that is going straight up. But the valve does not seem to stop water from coming in.

The boat is staying in for the winter so I am in a panic to get this resolved since it is getting cold quick. Any help or advice is appreciated.

 

[centerline]

the EXACT reason why gate valves are NOT acceptable valves for use on a thru hull.... they fail without notice, and you never know if they have failed open or if they failed closed or somewhere in between.... until you get in a pinch where you absolutely need it to work properly....

there is nothing you can do with the gate valve except change it out with a proper ball valve...
if you have the room to work, you may be able to do this with the boat in the water, but only if you're prepared for the task and d*mn sure of yourself... or work a tarp around under the outside of the hull so it will hold back the water while you work on it....

 

[eugenesdream24]

After I calmed down and could think clearly I remembered I have a holding tank, so I don't think these valves are thru hull. I think the two sinks both drain to the tank so the boat rocking and seeing the valve spill some water is just an indication that my tank is full to the brim.

Because if they were thru hull and were unable to close it would be an alarming amount of water coming through. Someone correct me if I am wrong.

 

[Apex]

The valve could be partially but not fully closed. If the valve is attached to the hull, then you will want to take care of that ASAP. Good Luck, pictures may help as well.

 

[petersea]

You need to follow the line and see where it leads . Most boats DO NOT have sink drains that go to holding tank. (exception being some lake boat with gray water tanks) Would be very surprised if your model does unless yours is very new or was on a lake I don't think it does. Even if it does it will need to be empty for the winter or it will freeze and crack the lines or tank. There should be a thru hull below the water line to shut off and way to drain the sink drain line. The reason you did not have an "alarming" amount of water come out of the line is due to physics and the water will only reach a level equal to the water level surrounding it. Yes, you need to fix this if you are going to keep boat in water over winter ! Also get rid of any gate valves you have on the boat, first choice would be to use a proper sea-cock second choice is a thru hull/ball value. Anything below the water line should be marine grade (not plastic or PVC and don't forget double clamp all hoses below water line)

Only other thought I have is you could (temporary fix for winter storage only) is the remove gate value (prepare to get wet !)and "cap" the thru hull until you can do a proper replacement. Pictures of your set up would be helpful.

 

[shemandr]

A short haul isn't THAT expensive.

 

[centerline]

if they were thru hull and were unable to close it would be an alarming amount of water coming through. Someone correct me if I am wrong.

if the valve was almost closed but not tightly, you would get as much water coming thru as the gate allowed...

if the valve is attached to the hull, its attached to a thru hull fitting... if its only installed in a line, then the line is not likely to be attached to a thru hull without another valve at the thru hull fitting...
but it would be a good thing to check, because you never know what or how a previous owner did repairs and modifications...

And this is important.... you NEED to know where all the thru hulls are located.

 

[wufibugs]

My boat also has a gate valve at the galley sink thru hull. I was thinking of replacing with a schedule 80 ball valve, but now wonder if using pvc below the waterline is ever a good idea. I would think it is less prone to corrosion, but may lack the strength

 

[Stu Jackson]

Once you figure out what you have, it'll help. We have plastic gate valves on our water supply from the tanks to the manifold to the fresh water faucet pump, perhaps OEM for Catalinas of 80s vintage. One of mine stopped working. I took it out, disassembled it and found that the O rings needed to be replaced. One trip to our local hardware store solved that. Simple. A real seacock is much better if indeed the plastic valve is being used on the galley sink out, but it seems odd, since more C30 owners would have reported it.

 

[petersea]

My boat also has a gate valve at the galley sink thru hull. I was thinking of replacing with a schedule 80 ball valve, but now wonder if using pvc below the waterline is ever a good idea. I would think it is less prone to corrosion, but may lack the strength

You need to get rid off that gate valve ! If you want to use a plastic "TYPE" for corrosion / electrolysis resistance check out the link below. Special polymer type material designed for underwater. I would never use "PVC" below the water line. Since your are in Calif you don't have the freezing issue we have in the northeast this type might work well they claim to be rated for below the water use and same strength as bronze. Still some old time purest would call them plastic and they should never be below the water line but new technology I would not be afraid of them. My only concern is I do not see a drain for winterizing but you could always blow the line out with air or shop vac water out..............Best of all, both this type and the bronze type are available on line right here in the SBO store ! !


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