Seacock question...

I have to replace a raw water pump on my Lehman 120 hp diesel. I have to shut off the seacock in order to take the pump out, but the seacock has a square head plug. Does anyone know which way to turn the plug in order to shut it off? Clockwise or counterclockwise? And how many turns? Thanks in advance.

The ones on my old boat were clockwise 45 degrees for closed.

Thanks, ben. I'll try that again. I couldn't turn it that way before. Counterclockwise, yes. Clockwise, no luck. But I'll try it again. I had to spray WD40 just to turn it counter.

crazyguamboy said:

I have to replace a raw water pump on my Lehman 120 hp diesel. I have to shut off the seacock in order to take the pump out, but the seacock has a square head plug. Does anyone know which way to turn the plug in order to shut it off? Clockwise or counterclockwise? And how many turns? Thanks in advance.

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Every seacock I have ever seen required a 90-degree turn from fully open to fully closed. Sometimes the handle will only allow it to turn one way because of a stop cast into the body. Others will allow the tapered cone to turn either way. The handle will indicate when the seacock is fully open when it is lined up with the outlet. When it is at 90-degrees to the outlet, the seacock is fully closed. If you don't have the handle, and it has a square headed plug, it is probably aligned like the photo below. Open will be aligned across the points, not the flats.

Thanks for the image, Larry. At least now I can envision what's going on when I turn it, which now appears I can turn either way. I did attach a pic of what I'm going through. Don't know if there's an advantage to having the square plug vs. a handle. But it sure is a pain in my stern side. Thanks again.

crazyguamboy said:

Don't know if there's an advantage to having the square plug vs. a handle. But it sure is a pain in my stern side. Thanks again.

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The handle has a square hole in it that fits over the square plug, kind of like a wrench. Sounds like you are missing a handle. Like this one. Might check out eBay.

Also check on the opposite side from the square plug. Many/most tapered valve seacocks have a nut or T handle you need to loosen to allow them to turn properly .

Hey, Capt. Bill. I did notice the threads opposite the square plug in the photo provided by Larry. I guess I could've done what you said had I known. Could've saved a few ounces of WD40. However, when I did turn the square plug, the opposite side where the nut is started to leak a little. I panicked, and put it back in the original position, then thought I'd go to the Trawler Forum to get the real scoop. And you all were great help. Thanks.

capt.bill11 said:

also check on the opposite side from the square plug. Many/most tapered valve seacocks have a nut or t handle you need to loosen to allow them to turn properly .

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this!

You should be "excising" your seacocks every month or two just so that they don't freeze up and so you can close them quickly in an emergency.

I would find handles for all of them and make sure they work and you can close them quickly if needed.

And yes, they turn 90 degrees from open to closed.

Greetings,
Mr. 11. "...you need to loosen to allow them to turn properly..." I have to disagree with that statement. IMO the sea cocks should be operable at all times without loosening anything. If they have to be loosened in order to turn and leak as a result of said loosening, they need to be serviced.

rwidman said:

You should be "excising" your seacocks every month or two just so that they don't freeze up and so you can close them quickly in an emergency.

I would find handles for all of them and make sure they work and you can close them quickly if needed.

And yes, they turn 90 degrees from open to closed.

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Actually if you close your seacocks when you leave the boat you'll reduce your chances of a flooding incident.

Likely similar to mine and I agree, you should not have to loosen the opposite nut to turn it. I certainly don't and it turns easily and does not leak. My handle has a little locking bolt on it so the handle does not fall off and is there if you need it and you hope you never do.

ksanders said:

Actually if you close your seacocks when you leave the boat you'll reduce your chances of a flooding incident.

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That is true. It's a choice between closing the seacocks and running the air conditioning and taking the chance of starting the engine while forgetting to open the seacock.

So - I leave my AC and engine seacocks open but close the one to the head. Others may make different choices.

RT Firefly said:

Greetings,
Mr. 11. "...you need to loosen to allow them to turn properly..." I have to disagree with that statement. IMO the sea cocks should be operable at all times without loosening anything. If they have to be loosened in order to turn and leak as a result of said loosening, they need to be serviced.

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For the large bronze seacocks we have in our boat, this is absolutely correct. The nuts (there should be two of them) opposite the lever are for adjusting the fit of the tapered, rotating barrel inside the valve body. The correct adjustment allows the barrel to be rotated easily (or at least fairly easily), but not so loose as to allow water to leak in. Once this adjustment has been set properly and the adjustment nut locked down with the outer lock nut, there should be no need to adjust it again unless the adjustment slips over time and the barrel either tightens or loosens too much.

Bronze seacocks need to be greased periodically. We do this by removing a freeze plug from the body of the valve and pushing waterproof grease into the hole with a finger while working the valve back and forth. Some people have replaced a freeze plug with a grease gun nipple.

We leave all the seacocks in our boat (there are 12 of them) closed whenever we are not using the boat EXCEPT the seacocks for the main engine raw water intakes. We leave them open in case someone needs to move the boat in an emergency.

RT Firefly said:

Greetings,
Mr. 11. "...you need to loosen to allow them to turn properly..." I have to disagree with that statement. IMO the sea cocks should be operable at all times without loosening anything. If they have to be loosened in order to turn and leak as a result of said loosening, they need to be serviced.

Click to expand...

The older seacocks on my DF 44 require the small handle to be loosened before you operate the larger lever and they always weep a small amount of water. (This may be a maintenance issue; I'm trying to find out more about this model.) The seacock in the photo is not from my boat, but ours are similar and I'm considering replacing all of them. The handles feel flimsy to me.

We have 3 of the tapered seacocks - 2 main engine and 1 for the gennie... damned if I can make them move. I have tried loosening the nuts on the other end.. tried tapping them to loosen it... sometimes I worry I will snap something if I try too hard

a mechanic who used to work on them for the PO loosened the nut and just tapped it lightly and was able to move them... either he is Hercules, I am a wimp, or I am doing something wrong... (all 3? )

Sometimes they will bind up inside if they haven't been worked and/or lubed regularly. So even loosening the adjusting and lock nuts won't let them move. Then a tap or two with a rubber mallet usually does the trick. You don't have to hit them hard, just tap them from one side and then the other, and they will generally come free pretty easily.

RT Firefly said:

Greetings,
Mr. 11. "...you need to loosen to allow them to turn properly..." I have to disagree with that statement. IMO the sea cocks should be operable at all times without loosening anything. If they have to be loosened in order to turn and leak as a result of said loosening, they need to be serviced.

Click to expand...

Well in a perfect world perhaps. But most seacocks don't get taken care of properly nor greased often enough. Plus when the get old it's hard to get them not to leak yet still move smoothly. So I have found over the years that loosening the nut is needed. But YMMV.

Marin said:

Sometimes they will bind up inside if they haven't been worked and/or lubed regularly. So even loosening the adjusting and lock nuts won't let them move. Then a tap or two with a rubber mallet usually does the trick. You don't have to hit them hard, just tap them from one side and then the other, and they will generally come free pretty easily.

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Yes and then the next time you have the boat out of the water you need to not only grease them but lap them in place using valve lapping compound. That will clean and renew the tapered fit. (Unless they are grooved beyond repair.) Then clean off the compound and grease them. I like using Super Lube.

Everything you ever wanted to know about seacocks and seacock maintenance but where afraid to ask.

http://www.pbase.com/mainecruising/tapered_cone_seacocks

Greetings,
Mr. 11. Agree 100% (post #20) Servicing Tapered Cone Seacocks Photo Gallery by Compass Marine How To at pbase.com
That is exactly my point. A properly serviced seacock (SC) need not be loosened to function. When we took possession of our current vessel there was a 1' piece of pipe beside the main engine SC that HAD to be used to operate the valve. There was a stringer within 3" of the SC and as a result the plug could not be removed for proper servicing/lapping. A 3" hole saw solved THAT situation.
Mr. CP. Dayum....3 minutes late...

RT Firefly said:

Mr. CP. Dayum....3 minutes late...

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It happens RT. Normally I'm the one late

Angus

You have the old Groco rubber plug type seacock. They were a top notch unit.
The Tee handle must be loosened a tad to rotate the plug. A bit of water will come in - normal - when the Tee is loosened and the plug turned. Once retightened the weep stops.

Unfortunately they are no longer available. I've looked from time to time when in a used marine goods store and have never seen any that I can use.





The taper type seacocks that started the thread, in addition to being adjusted properly, the need for grease now, they may also need to be lapped lightly are also top notch units.

Use of a light Clover compound, lapping, will lightly grind the two tapers and make for a good fit.

The compound must be thoroughly washed off with solvent and rags. Any grit remaining will continue to grind eventually damaging the taper. Not hard, just need some attention to details.

And yes, they should be exercised periodically and greaed to be sure they don;t freeze.

The rest of the world changed to ball valves for a reason. Taper plug valves are typically used in slurry service, and not much else.

>The rest of the world changed to ball valves for a reason.<

Yes COST, you will find 60 -80 year old tapered plug sea cocks that are servicable.

The SS ball stuff is simply discarded, as it should be,

Items that can not be serviced do not belong in a boat that is not also dispposable.

C lectric said:

Angus

You have the old Groco rubber plug type seacock. They were a top notch unit.
The Tee handle must be loosened a tad to rotate the plug. A bit of water will come in - normal - when the Tee is loosened and the plug turned. Once retightened the weep stops.

Unfortunately they are no longer available. I've looked from time to time when in a used marine goods store and have never seen any that I can use.

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C lectric, thanks for ID-ing the Grocos. A simple search found a great discussion (featuring our own HopCar) on what it takes to replace these aging models. Groco SV Seacock Testing Prior to Installation - Cruisers & Sailing Forums

Still thinking about replacing them since Groco stopped making parts for them, including the rubber wear parts, in the 1990s. Too bad because they feel like they were built like tanks.

FF said:

>The rest of the world changed to ball valves for a reason.<

Yes COST, you will find 60 -80 year old tapered plug sea cocks that are servicable.

The SS ball stuff is simply discarded, as it should be,

Items that can not be serviced do not belong in a boat that is not also dispposable.

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+1 I have seen marine-rated ball valves/seacocks fail and leak too. In one case, the shaft broke off in the ball which allowed the handle to turn normally, but did not rotate the ball. In my case, I 'closed' the seacock and pulled off a 1" hose only to have the full force of water from that wide-open seacock hit me right in the face. I was able to get the hose back on, but changed it out next yard period. If that had been a taper plug seacock, the handle and shaft could not have failed like it did without warning. And, if it had stuck open, it could have likely been serviced in place without having to be removed from the hull. Just exercise and lube them occasionally and they will last a long time. BTW, I had been 'exercising' that ball-type seacock regularly, but obviously, only the handle was moving, not the ball!

Larry
M/V Boomarang

FF said:

............Items that can not be serviced do not belong in a boat that is not also dispposable.

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That's not a good blanket statement. Electronics is a good example. Although they may be serviceable, at some point replacement is the better option providing new and improved features.

Other items, like small bilge pumps aren't worth the trouble of trying to find parts and spending time repairing them when replacement is cheap and simple and guarantees a working product.

And of course, no matter how serviceable a product is, there may come a time when the manufacturer no longer supplies parts or goes out of business.

Angus99, I just typed up a long discourse on the Groco seacock but I see it's already been covered. Never mind.