Not What I Am Expecting to See from Seacock

[faa50]

Over the past year I've learned when it comes to maintenance and repairs aboard, plan to experience surprises. Well, I got one yesterday. Looking to hear from anyone with knowledge on this type of seacock.

First a little background: I have two 3YM30 Yanmar diesel engines linked to two Yanmar's SD20 saildrives aboard a 2014 Lagoon 39 catamaran.

Yesterday, I thought I had closed the seacock located at the base of the SD20. This seacock has a coolant hose leading from it to the sea strainer then onto the water pump">raw water pump.

Located on the horizontal seacock brass fitting located on the top of the shaft printed are directions to operate: "turn forward to close / turn aft to open." I turned the handle forward till it stopped.

Next, when I proceeded to loosen the two C clamps and removed the coolant hose, seawater gushed forth from the seacock pipe opening.

This seacock is unlike others on this boat and other seacocks I've seen on friend's boats. This seacock doesn't have a 3" or 4" handle to turn like the other 10 seacocks on this boat

Instead, it has a horizontial bronze shaft that has a thin 1/4" long stainless rod 4" that goes through the bronze shaft: intended to serve as a handle to turn the shaft. At the end of the shaft is a smaller shaft inside the larger that looks like it might work as a plunger. In addition there is a light weight 3" horseshoe shaped steel clip.

Anyone know what I'm doing wrong to close this seacock?

Owner's manual makes no mention of "how" to open or close other than what I've previously discussed above.

[HopCar]

Going to need a photo.

[zeehag]

it takes over 1000 words to provide that which one foto will offer.. please affix fotos so we can see what you are describing. thankyou

[wiekeith]

It's a gate valve. It takes about 15 turns to close it, but inevitably it gets clogged with sea-water deposits so it can't be closed. IMHO it's a stupid idea. I changed mine for a standard ball valve.

[sailorchic34]

Sounds like that might be a real seacock, and not a ball valve. generally most manufacturers have the handle in line with the seacock flow direction for open and 90 degrees to the flow for close. That oddly is the standard world wide for ball and plug valves.

[lordgeoff]

On a mates boat I have seen the actual ball valve had completely disintegrated.
The handle moved fine and looked like everything was working but in actual fact there was nothing inside. Wasn't noticed until the valve was taken out for inspection.

[clownfishsydney]

Same as ours, just need to completely turn it.

[dan swift]

I have the same valve on my sd40 I have heard of this problem before and the Soulition is to replace the valve. It is a globe valve and yanmar doesn't use them any more. I am going to replace mine this summer. I don't know if it's wise but I am going to block the intake under water with earmuffs and replace it with a ball valve. Not sure it is a good idea, but I am going to do it any way.

[wiekeith]

Originally Posted by dan swift

I have the same valve on my sd40 I have heard of this problem before and the Soulition is to replace the valve. It is a globe valve and yanmar doesn't use them any more. I am going to replace mine this summer. I don't know if it's wise but I am going to block the intake under water with earmuffs and replace it with a ball valve. Not sure it is a good idea, but I am going to do it any way.

I went through the process of thinking of ways of blocking the water inlet when I changed the valve on my SD50, can't remember what they all were, but in the end I just changed it without blocking the inlet. Didn't get too much water in, not much different to removing a log and inserting the blank really, you just need to be a bit braver

Oh, and make sure the replacement valve, which you are going to fit very quickly to stop the flow of water, is in the closed position

[ArmyDaveNY]

Originally Posted by dan swift

I have the same valve on my sd40 I have heard of this problem before and the Soulition is to replace the valve. It is a globe valve and yanmar doesn't use them any more. I am going to replace mine this summer. I don't know if it's wise but I am going to block the intake under water with earmuffs and replace it with a ball valve. Not sure it is a good idea, but I am going to do it any way.

If you just need to change the valve and not the through hull, try this:
Seabung

The video on the site pretty much explains it in less than a minutes.

[ggray]

My 17 year old 3GM30s have the same valve. Yammer calls it a Kingston Cock.

At every hauling out, I remove the valves and clean and exercise with WD40, then lube with something a bit heavier. The originals still work fine.

The valves do start to get stiff between lubes, though, so I got a socket (9/16 12 point, I think, fit best) and made notches (drill plus hack saw) so it would fit over the T handle, and allow me to exert more force in a symmetrical manner. Better than hooking a box wrench over one side.

I had thought about replacing it with a ball valve, specifically a three-way to assist in winterizing, but worried that it might be more vulnerable to freezing.

[sgancarz]

Sounds like it might possibly be an old styled tapered seacock that they lost the handle for.