Sea Cocks
 

Should sea cocks (under the water line) be ball valves or gate valves?

Sea Cocks
 

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On Thu, 08 Jan 2004 05:44:34 GMT,
John Smith wrote:
Should sea cocks (under the water line) be ball valves or gate valves?



Never gate valves, above or below the water line. Gate valves break,
they can easily jam in the open position, they give little or no
indication of if they are open, closed or some point inbetween. They are
rarely made of suitable material for salt water environments, and they
cost no less than a decent quality ball valve. If it's for a through
hull, gate valves lack the support for bolting through.

You can sort of get away with them for internal stuff, but you are
better off with ball valves for that too. The 1/4" bronze ones at
Ballard Hardware are about $6 each, and the SS ones, are ~$18 iirc.

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--
Jim Richardson http://www.eskimo.com/~warlock

Sea Cocks
 

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Thu, 08 Jan 2004 05:44:34 GMT,
John Smith wrote:
Should sea cocks (under the water line) be ball valves or gate valves?



Never gate valves, above or below the water line. Gate valves break,
they can easily jam in the open position, they give little or no
indication of if they are open, closed or some point inbetween. They are
rarely made of suitable material for salt water environments, and they
cost no less than a decent quality ball valve. If it's for a through
hull, gate valves lack the support for bolting through.

You can sort of get away with them for internal stuff, but you are
better off with ball valves for that too. The 1/4" bronze ones at
Ballard Hardware are about $6 each, and the SS ones, are ~$18 iirc.

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Version: GnuPG v1.2.4 (GNU/Linux)

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mNmZXDFWHP64c2VkzyGN6Cc=
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--
Jim Richardson http://www.eskimo.com/~warlock

Sea Cocks
 

Never gate type, always 1/4 turn somethings, barrel, ball, tapered
plug, etc, Also, always, a proper flanged base seacock with a backing
pad and ball drain, not an inline valve attached to a thruhull spud.
Conbraco, Groco, Perko, Forespar etc.



On Thu, 08 Jan 2004 05:44:34 GMT, "John Smith"
wrote:

Should sea cocks (under the water line) be ball valves or gate valves?

Sea Cocks
 

Never gate type, always 1/4 turn somethings, barrel, ball, tapered
plug, etc, Also, always, a proper flanged base seacock with a backing
pad and ball drain, not an inline valve attached to a thruhull spud.
Conbraco, Groco, Perko, Forespar etc.



On Thu, 08 Jan 2004 05:44:34 GMT, "John Smith"
wrote:

Should sea cocks (under the water line) be ball valves or gate valves?

Sea Cocks
 

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Steve
s/v Good Intentions

Sea Cocks
 

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Steve
s/v Good Intentions

Sea Cocks
 

Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief benefits is
that you can disassemble them without taking apart the piping, something that
can't be done with ball valves. Also, if they happen to freeze up, they are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat last
spring, and couldn't find any that we could actually get in time. However, at
some boatyard session in the not-too-distant future I have to replace (upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief benefits is
that you can disassemble them without taking apart the piping, something that
can't be done with ball valves. Also, if they happen to freeze up, they are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat last
spring, and couldn't find any that we could actually get in time. However, at
some boatyard session in the not-too-distant future I have to replace (upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

Wow. Live and learn. I have no clue what a plug valve is, but I like
the sound of it. Off to Google I go.

R.


On Thu, 08 Jan 2004 12:44:16 -0500, DSK wrote:

Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief benefits is
that you can disassemble them without taking apart the piping, something that
can't be done with ball valves. Also, if they happen to freeze up, they are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat last
spring, and couldn't find any that we could actually get in time. However, at
some boatyard session in the not-too-distant future I have to replace (upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

Wow. Live and learn. I have no clue what a plug valve is, but I like
the sound of it. Off to Google I go.

R.


On Thu, 08 Jan 2004 12:44:16 -0500, DSK wrote:

Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief benefits is
that you can disassemble them without taking apart the piping, something that
can't be done with ball valves. Also, if they happen to freeze up, they are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat last
spring, and couldn't find any that we could actually get in time. However, at
some boatyard session in the not-too-distant future I have to replace (upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

A proper sea cock, in the strictest sense (was) a tapered plug valve with a
flange on the outboard side and internal threads for the throught hull.. The
flange would be bolted though to the outside with a fitted block on the
inside. The through hull was just that and provide little or no structural
strength the the installation..

Pipe threads and none tapered through hull threads are weak because of the
amount of base metal that is removed during the threading process.

Today, you will seldom find a true and proper sea cock. What you will find
is a through hull with a valve threaded on the end of the inboard end of the
threads.. Even this is not a proper installation because the threads in the
standard valve will be tapered while the through hull threads are straight..
When tightened up, only the first couple threads will be holding the
pressure and providing mechanical strength.

There is often the recommendation that you try standing on your through hull
valve to ensure that the through hull is still sound.. That may be an
indication of strength of the exposed threads, however straight threads into
a tapered valve thread really leads to a valve that could easily vibrate or
be accidently loosened.

Myself, I'm using the Forespar Marelon flanged Seacocks, with Marelon
through hulls.. (objective is to have all non-metalic/non-conductive
fittings below the waterline)

The flange bolts were a problem so I used flat head machine screws and
counter sunk the heads and epoxyed over them to prevent contact with the
water. I will have to keep an eye on these over time to see if there is any
evidence of water intrusion..


--
My opinion and experience. FWIW

Steve
s/v Good Intentions

Sea Cocks
 

A proper sea cock, in the strictest sense (was) a tapered plug valve with a
flange on the outboard side and internal threads for the throught hull.. The
flange would be bolted though to the outside with a fitted block on the
inside. The through hull was just that and provide little or no structural
strength the the installation..

Pipe threads and none tapered through hull threads are weak because of the
amount of base metal that is removed during the threading process.

Today, you will seldom find a true and proper sea cock. What you will find
is a through hull with a valve threaded on the end of the inboard end of the
threads.. Even this is not a proper installation because the threads in the
standard valve will be tapered while the through hull threads are straight..
When tightened up, only the first couple threads will be holding the
pressure and providing mechanical strength.

There is often the recommendation that you try standing on your through hull
valve to ensure that the through hull is still sound.. That may be an
indication of strength of the exposed threads, however straight threads into
a tapered valve thread really leads to a valve that could easily vibrate or
be accidently loosened.

Myself, I'm using the Forespar Marelon flanged Seacocks, with Marelon
through hulls.. (objective is to have all non-metalic/non-conductive
fittings below the waterline)

The flange bolts were a problem so I used flat head machine screws and
counter sunk the heads and epoxyed over them to prevent contact with the
water. I will have to keep an eye on these over time to see if there is any
evidence of water intrusion..


--
My opinion and experience. FWIW

Steve
s/v Good Intentions

Sea Cocks
 

GROCO used to make them. Probably still do. They have
a rubber plug. My current boat has ones with bronze plugs,
not sure of the brand though.

Doug
s/v Callista

wrote in message
...
Wow. Live and learn. I have no clue what a plug valve is, but I like
the sound of it. Off to Google I go.

R.


On Thu, 08 Jan 2004 12:44:16 -0500, DSK wrote:

Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug
valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief
benefits is
that you can disassemble them without taking apart the piping, something
that
can't be done with ball valves. Also, if they happen to freeze up, they
are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat
last
spring, and couldn't find any that we could actually get in time.
However, at
some boatyard session in the not-too-distant future I have to replace
(upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

GROCO used to make them. Probably still do. They have
a rubber plug. My current boat has ones with bronze plugs,
not sure of the brand though.

Doug
s/v Callista

wrote in message
...
Wow. Live and learn. I have no clue what a plug valve is, but I like
the sound of it. Off to Google I go.

R.


On Thu, 08 Jan 2004 12:44:16 -0500, DSK wrote:

Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug
valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief
benefits is
that you can disassemble them without taking apart the piping, something
that
can't be done with ball valves. Also, if they happen to freeze up, they
are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat
last
spring, and couldn't find any that we could actually get in time.
However, at
some boatyard session in the not-too-distant future I have to replace
(upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

In article ,
"John Smith" wrote:

Should sea cocks (under the water line) be ball valves or gate valves?

Another vote to remove all gate valves immediately. Yours will be old
enough that you don't know when they're going to break (or if they've
broken already). I'd be SO worried, I'd haul the boat just do do that
job.

BTW, often it's lots faster to cut old gate valves off than try to
unscrew them. A friend's set of railroad socket wrenches and a 6'
breaker bar with two beefy guys couldn't unscrew ours. A jig saw and
metal cutting blade got rid of it in 15 minutes.

Ball valves are the most usual type you find in marine stores. They come
with or with flanges. For below the waterline in locations exposed to
knocks or stepping on, I prefer the flanged type. Though others say they
don't mate properly with through hulls, the ones I've gotten had plenty
of threads in contact. [Seemed to take forever to screw them on!]

I would prefer proper sea cocks -- the tapered plug type -- but our ball
valves have worked well for just about a decade, so I'm not going to
worry about it.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Sea Cocks
 

In article ,
"John Smith" wrote:

Should sea cocks (under the water line) be ball valves or gate valves?

Another vote to remove all gate valves immediately. Yours will be old
enough that you don't know when they're going to break (or if they've
broken already). I'd be SO worried, I'd haul the boat just do do that
job.

BTW, often it's lots faster to cut old gate valves off than try to
unscrew them. A friend's set of railroad socket wrenches and a 6'
breaker bar with two beefy guys couldn't unscrew ours. A jig saw and
metal cutting blade got rid of it in 15 minutes.

Ball valves are the most usual type you find in marine stores. They come
with or with flanges. For below the waterline in locations exposed to
knocks or stepping on, I prefer the flanged type. Though others say they
don't mate properly with through hulls, the ones I've gotten had plenty
of threads in contact. [Seemed to take forever to screw them on!]

I would prefer proper sea cocks -- the tapered plug type -- but our ball
valves have worked well for just about a decade, so I'm not going to
worry about it.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Sea Cocks
 

I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the
handle/valve, and, perhaps, a spring to hold it firmly down? - but that was
not the deal. I presume from reading the various chatter on the topic that
perhaps it (taper) refers to the threads at the bottom of the
valve/thru-hull?

In any event, I'm not the least bit sure how they're better than ball
valves, as that's what they look like. Those of you familiar with the
benefits of the type over a ball, what is their superiority?

Thanks.

L8R

Skip

--
"And then again, when you sit at the helm of your little ship on a clear
night, and gaze at the countless stars overhead, and realize that you are
quite alone on a great, wide sea, it is apt to occur to you that in the
general scheme of things you are merely an insignificant speck on the
surface of the ocean; and are not nearly so important or as self-sufficient
as you thought you were. Which is an exceedingly wholesome thought, and one
that may effect a permanent change in your deportment that will be greatly
appreciated by your friends."- James S. Pitkin

Sea Cocks
 

I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the
handle/valve, and, perhaps, a spring to hold it firmly down? - but that was
not the deal. I presume from reading the various chatter on the topic that
perhaps it (taper) refers to the threads at the bottom of the
valve/thru-hull?

In any event, I'm not the least bit sure how they're better than ball
valves, as that's what they look like. Those of you familiar with the
benefits of the type over a ball, what is their superiority?

Thanks.

L8R

Skip

--
"And then again, when you sit at the helm of your little ship on a clear
night, and gaze at the countless stars overhead, and realize that you are
quite alone on a great, wide sea, it is apt to occur to you that in the
general scheme of things you are merely an insignificant speck on the
surface of the ocean; and are not nearly so important or as self-sufficient
as you thought you were. Which is an exceedingly wholesome thought, and one
that may effect a permanent change in your deportment that will be greatly
appreciated by your friends."- James S. Pitkin

Sea Cocks
 

"Skip Gundlach" wrote in
message ink.net...
I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily
position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the

Your visions were correct. A plug valve has a tappered plug, just as you
discribe here..

If you are looking as something that resembles a ball valve then your not
looking at a true plug valve.

I have been boating for 45 yrs and all of my boats until 10 years ago had
tapered plug seacocks. (my last boat being a '76 Cheoy Lee Clipper 33) This
boat had 'knock off' tapered plug valves. That was the standard and the
proper valve or sea cock in boats built up into the '70s.

I just wish I had a good online reference to what a proper tapered plug
valve looks like..

I'll do some Googling on my own.

Steve
s/v Good Intentions

Sea Cocks
 

"Skip Gundlach" wrote in
message ink.net...
I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily
position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the

Your visions were correct. A plug valve has a tappered plug, just as you
discribe here..

If you are looking as something that resembles a ball valve then your not
looking at a true plug valve.

I have been boating for 45 yrs and all of my boats until 10 years ago had
tapered plug seacocks. (my last boat being a '76 Cheoy Lee Clipper 33) This
boat had 'knock off' tapered plug valves. That was the standard and the
proper valve or sea cock in boats built up into the '70s.

I just wish I had a good online reference to what a proper tapered plug
valve looks like..

I'll do some Googling on my own.

Steve
s/v Good Intentions

Sea Cocks
 

"Steve" wrote in message
...

I just wish I had a good online reference to what a proper tapered plug
valve looks like..


OK, here is the best I could do with a quick Google. It is a commercial
TAPERED PLUG VALVE.
http://www.conind.com/pdf/plug%20valve.pdf

It's not a sea cock but it is a tapered plug valve and has straight threads
on the inlet side and standard pipe threads on the outlet side. In this
valve the plug could be removed and the plug lapped/overhauled without
removing the valve from the system.. With a plug in the through hull, it
could be serviced in the water. (I've done this many times) You could never
do this with a ball valve since the ball can not be easily removed and if it
is, there is no way to resurface the ball surface if scored.

Steve
s/v Good Intentions

Sea Cocks
 

"Steve" wrote in message
...

I just wish I had a good online reference to what a proper tapered plug
valve looks like..


OK, here is the best I could do with a quick Google. It is a commercial
TAPERED PLUG VALVE.
http://www.conind.com/pdf/plug%20valve.pdf

It's not a sea cock but it is a tapered plug valve and has straight threads
on the inlet side and standard pipe threads on the outlet side. In this
valve the plug could be removed and the plug lapped/overhauled without
removing the valve from the system.. With a plug in the through hull, it
could be serviced in the water. (I've done this many times) You could never
do this with a ball valve since the ball can not be easily removed and if it
is, there is no way to resurface the ball surface if scored.

Steve
s/v Good Intentions

Sea Cocks
 

"Steve" wrote in message
...

Myself, I'm using the Forespar Marelon flanged Seacocks,
with Marelon
through hulls.. (objective is to have all
non-metalic/non-conductive
fittings below the waterline)

The flange bolts were a problem so I used flat head
machine screws and
counter sunk the heads and epoxyed over them to prevent
contact with the
water. I will have to keep an eye on these over time to
see if there is any
evidence of water intrusion..

Steve,
Are your machine screws stainless or other metal? If
stainless, keep an eye out for corrosion under the epoxy.
Stainless doesn't like to be deprived of oxygen, as you
know!

--
JimB
Yacht Rapaz, sadly for sale:

http://homepage.ntlworld.com/jim.bae...cification.htm
jim(dot)baerselman(at)ntlworld(dot)com

Sea Cocks
 

"Steve" wrote in message
...

Myself, I'm using the Forespar Marelon flanged Seacocks,
with Marelon
through hulls.. (objective is to have all
non-metalic/non-conductive
fittings below the waterline)

The flange bolts were a problem so I used flat head
machine screws and
counter sunk the heads and epoxyed over them to prevent
contact with the
water. I will have to keep an eye on these over time to
see if there is any
evidence of water intrusion..

Steve,
Are your machine screws stainless or other metal? If
stainless, keep an eye out for corrosion under the epoxy.
Stainless doesn't like to be deprived of oxygen, as you
know!

--
JimB
Yacht Rapaz, sadly for sale:

http://homepage.ntlworld.com/jim.bae...cification.htm
jim(dot)baerselman(at)ntlworld(dot)com

Sea Cocks
 

On Thu, 8 Jan 2004 18:48:55 -0800, "Steve" wrote:


"Skip Gundlach" wrote in
message ink.net...
I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily
position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the

Your visions were correct. A plug valve has a tappered plug, just as you
discribe here..

If you are looking as something that resembles a ball valve then your not
looking at a true plug valve.

I have been boating for 45 yrs and all of my boats until 10 years ago had
tapered plug seacocks. (my last boat being a '76 Cheoy Lee Clipper 33) This
boat had 'knock off' tapered plug valves. That was the standard and the
proper valve or sea cock in boats built up into the '70s.

I just wish I had a good online reference to what a proper tapered plug
valve looks like..

You may see what you are looking for at

http://spartanmarine.com/ and click on "seacocks". That is what I
have on my boat, but I'll be honest. These things, while heavy and
stout, do tend to want to stick if not opened and closed regularly. I
am not sure I wouldn't prefer ball valves or the Forespar marelon, but
I am still pondering. My current disgruntlement probably brought on
by the fact that two of mine are now stuck in the open position, which
doesn't make me happy at all as my boat is in the water over the
winter. Something I have to take care of ASAP.



I'll do some Googling on my own.

Steve
s/v Good Intentions

Sea Cocks
 

On Thu, 8 Jan 2004 18:48:55 -0800, "Steve" wrote:


"Skip Gundlach" wrote in
message ink.net...
I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily
position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the

Your visions were correct. A plug valve has a tappered plug, just as you
discribe here..

If you are looking as something that resembles a ball valve then your not
looking at a true plug valve.

I have been boating for 45 yrs and all of my boats until 10 years ago had
tapered plug seacocks. (my last boat being a '76 Cheoy Lee Clipper 33) This
boat had 'knock off' tapered plug valves. That was the standard and the
proper valve or sea cock in boats built up into the '70s.

I just wish I had a good online reference to what a proper tapered plug
valve looks like..

You may see what you are looking for at

http://spartanmarine.com/ and click on "seacocks". That is what I
have on my boat, but I'll be honest. These things, while heavy and
stout, do tend to want to stick if not opened and closed regularly. I
am not sure I wouldn't prefer ball valves or the Forespar marelon, but
I am still pondering. My current disgruntlement probably brought on
by the fact that two of mine are now stuck in the open position, which
doesn't make me happy at all as my boat is in the water over the
winter. Something I have to take care of ASAP.



I'll do some Googling on my own.

Steve
s/v Good Intentions

Sea Cocks
 

I don't know that anyone still makes the traditional in-line tapered
barerel seacocks any more. Wilcox-Critenden made the last that I know
of. Spartan Marine still makes a horozontal barrel but that is about
it. Groco and Conbraco/Apollo make only ball type.

There are several reasons that ball type valves have replaced tapered
plugs. Tapered barrels have to be exactly mated to the valve body.
That means they are expensive to make but that is not the main reason.
First because of the close tolerances, the barrel cannot be replaced.
The whole seacock must be replaced. Second, because of the large
contact area they are much harder to turn and more prone to freezing up.
Third, with use the barrel tends to get wasp waisted and leaks.
Tightning becomes a delicate balance between stopping the leak and
squeezing out the grease which leads to freezing up.

Ball type seacocks use standard parts so they are less expensive to make
and easier to replace parts. The nylon seats accomodate any variation
in tolerance due to wear and are fairly easy to replace.

Keep in mind that I am talking about ball type seacocks. Not ball
valves. Seacocks have bases that bolt to the hull. Ball valves are
fine for use down stream but not screwed to a throughull.

Jere Lull wrote:
In article ,
"John Smith" wrote:


Should sea cocks (under the water line) be ball valves or gate valves?


Another vote to remove all gate valves immediately. Yours will be old
enough that you don't know when they're going to break (or if they've
broken already). I'd be SO worried, I'd haul the boat just do do that
job.

BTW, often it's lots faster to cut old gate valves off than try to
unscrew them. A friend's set of railroad socket wrenches and a 6'
breaker bar with two beefy guys couldn't unscrew ours. A jig saw and
metal cutting blade got rid of it in 15 minutes.

Ball valves are the most usual type you find in marine stores. They come
with or with flanges. For below the waterline in locations exposed to
knocks or stepping on, I prefer the flanged type. Though others say they
don't mate properly with through hulls, the ones I've gotten had plenty
of threads in contact. [Seemed to take forever to screw them on!]

I would prefer proper sea cocks -- the tapered plug type -- but our ball
valves have worked well for just about a decade, so I'm not going to
worry about it.


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Sea Cocks
 

I don't know that anyone still makes the traditional in-line tapered
barerel seacocks any more. Wilcox-Critenden made the last that I know
of. Spartan Marine still makes a horozontal barrel but that is about
it. Groco and Conbraco/Apollo make only ball type.

There are several reasons that ball type valves have replaced tapered
plugs. Tapered barrels have to be exactly mated to the valve body.
That means they are expensive to make but that is not the main reason.
First because of the close tolerances, the barrel cannot be replaced.
The whole seacock must be replaced. Second, because of the large
contact area they are much harder to turn and more prone to freezing up.
Third, with use the barrel tends to get wasp waisted and leaks.
Tightning becomes a delicate balance between stopping the leak and
squeezing out the grease which leads to freezing up.

Ball type seacocks use standard parts so they are less expensive to make
and easier to replace parts. The nylon seats accomodate any variation
in tolerance due to wear and are fairly easy to replace.

Keep in mind that I am talking about ball type seacocks. Not ball
valves. Seacocks have bases that bolt to the hull. Ball valves are
fine for use down stream but not screwed to a throughull.

Jere Lull wrote:
In article ,
"John Smith" wrote:


Should sea cocks (under the water line) be ball valves or gate valves?


Another vote to remove all gate valves immediately. Yours will be old
enough that you don't know when they're going to break (or if they've
broken already). I'd be SO worried, I'd haul the boat just do do that
job.

BTW, often it's lots faster to cut old gate valves off than try to
unscrew them. A friend's set of railroad socket wrenches and a 6'
breaker bar with two beefy guys couldn't unscrew ours. A jig saw and
metal cutting blade got rid of it in 15 minutes.

Ball valves are the most usual type you find in marine stores. They come
with or with flanges. For below the waterline in locations exposed to
knocks or stepping on, I prefer the flanged type. Though others say they
don't mate properly with through hulls, the ones I've gotten had plenty
of threads in contact. [Seemed to take forever to screw them on!]

I would prefer proper sea cocks -- the tapered plug type -- but our ball
valves have worked well for just about a decade, so I'm not going to
worry about it.


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Sea Cocks
 

I don't think they even make those any more, do they? I know I had a willing
buyer for a set that I replaced on my Krogen with Groco seacocks.

"DSK" wrote in message
...
Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug
valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief
benefits is
that you can disassemble them without taking apart the piping, something
that
can't be done with ball valves. Also, if they happen to freeze up, they
are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat
last
spring, and couldn't find any that we could actually get in time. However,
at
some boatyard session in the not-too-distant future I have to replace
(upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

I don't think they even make those any more, do they? I know I had a willing
buyer for a set that I replaced on my Krogen with Groco seacocks.

"DSK" wrote in message
...
Steve wrote:

As others have stated, Gate Valve are not suited for marine use and
especially for below the waterline.

However, IMHO, the plug valve is superior to the ball valve. The plug
valve
can be taken apart and cleaned or repaired. It seems that they would be
cheaper to manufacture as well..

Agreed. Good plug valves are hard to find, though. One of the chief
benefits is
that you can disassemble them without taking apart the piping, something
that
can't be done with ball valves. Also, if they happen to freeze up, they
are
easier to unfreeze.

I looked all over for plug valves to replace some seacocks on our boat
last
spring, and couldn't find any that we could actually get in time. However,
at
some boatyard session in the not-too-distant future I have to replace
(upsize)
two seacocks and intend to have plug valves on hand for that job.

Fresh Breezes- Doug King

Sea Cocks
 

I personally don't think they are as good. I replaced three on my boat with
Groco seacocks. You are correct about the plug valves working like the
valves on titration tubes. You would turn the rubber plug to the position
then tighten a screw on the other side which would smush the rubber plug
inside the housing, locking it in place. They had to be taken apart annually
or so and cleaned and lubed. When you tighten them up, the rubber squeezes
up into the openings, especially in the closed position. You don't have any
of these problems with ball valve seacocks, which are usually ss on Teflon
seats.

"Skip Gundlach" wrote in
message ink.net...
I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily
position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the
handle/valve, and, perhaps, a spring to hold it firmly down? - but that
was
not the deal. I presume from reading the various chatter on the topic
that
perhaps it (taper) refers to the threads at the bottom of the
valve/thru-hull?

In any event, I'm not the least bit sure how they're better than ball
valves, as that's what they look like. Those of you familiar with the
benefits of the type over a ball, what is their superiority?

Thanks.

L8R

Skip

--
"And then again, when you sit at the helm of your little ship on a clear
night, and gaze at the countless stars overhead, and realize that you are
quite alone on a great, wide sea, it is apt to occur to you that in the
general scheme of things you are merely an insignificant speck on the
surface of the ocean; and are not nearly so important or as
self-sufficient
as you thought you were. Which is an exceedingly wholesome thought, and
one
that may effect a permanent change in your deportment that will be greatly
appreciated by your friends."- James S. Pitkin

Sea Cocks
 

I personally don't think they are as good. I replaced three on my boat with
Groco seacocks. You are correct about the plug valves working like the
valves on titration tubes. You would turn the rubber plug to the position
then tighten a screw on the other side which would smush the rubber plug
inside the housing, locking it in place. They had to be taken apart annually
or so and cleaned and lubed. When you tighten them up, the rubber squeezes
up into the openings, especially in the closed position. You don't have any
of these problems with ball valve seacocks, which are usually ss on Teflon
seats.

"Skip Gundlach" wrote in
message ink.net...
I'm a bit confused, apparently, by semantics or my limited exposure...

I hadn't heard of plug valves, so I went looking. What I saw looked about
like every ball valve on the insides - except none had easily
position-noted
lever handles on the outsides.

A tapered plug valve led to visions of the kind of valves I used in
titration in school - a tapered seat with a matching taper on the
handle/valve, and, perhaps, a spring to hold it firmly down? - but that
was
not the deal. I presume from reading the various chatter on the topic
that
perhaps it (taper) refers to the threads at the bottom of the
valve/thru-hull?

In any event, I'm not the least bit sure how they're better than ball
valves, as that's what they look like. Those of you familiar with the
benefits of the type over a ball, what is their superiority?

Thanks.

L8R

Skip

--
"And then again, when you sit at the helm of your little ship on a clear
night, and gaze at the countless stars overhead, and realize that you are
quite alone on a great, wide sea, it is apt to occur to you that in the
general scheme of things you are merely an insignificant speck on the
surface of the ocean; and are not nearly so important or as
self-sufficient
as you thought you were. Which is an exceedingly wholesome thought, and
one
that may effect a permanent change in your deportment that will be greatly
appreciated by your friends."- James S. Pitkin

Sea Cocks
 

"felton" wrote in message
I am still pondering. My current disgruntlement probably brought on
by the fact that two of mine are now stuck in the open position, which
doesn't make me happy at all as my boat is in the water over the
winter. Something I have to take care of ASAP.



Shame on you Felton. You should have been cycling those sea cocks every time
you used the boat or at least once a month.. Even the Forspar Marelon valves
have a tag on the handle recommending that they be cylcled monthly and
lubricated annually.

However, I'm afraid I'm guilty of this same neglect.

You should be able to free these valves by loosing the nut on the bottom of
the plug, tap it with a soft hammer (or hammer on a block of wood). Since
the plug is tappered it should come loose from the seat and rotate.. After
operating it though a number of cycles, adjust the nut just enough to
lightly hold the plug in place.

Steve
s/v Good Intentions

Sea Cocks
 

"felton" wrote in message
I am still pondering. My current disgruntlement probably brought on
by the fact that two of mine are now stuck in the open position, which
doesn't make me happy at all as my boat is in the water over the
winter. Something I have to take care of ASAP.



Shame on you Felton. You should have been cycling those sea cocks every time
you used the boat or at least once a month.. Even the Forspar Marelon valves
have a tag on the handle recommending that they be cylcled monthly and
lubricated annually.

However, I'm afraid I'm guilty of this same neglect.

You should be able to free these valves by loosing the nut on the bottom of
the plug, tap it with a soft hammer (or hammer on a block of wood). Since
the plug is tappered it should come loose from the seat and rotate.. After
operating it though a number of cycles, adjust the nut just enough to
lightly hold the plug in place.

Steve
s/v Good Intentions

Sea Cocks
 

"JimB" wrote in message
...

Are your machine screws stainless or other metal? If
stainless, keep an eye out for corrosion under the epoxy.
Stainless doesn't like to be deprived of oxygen, as you
know!


I managed to find monel bolts for these sea cock flanges. ( I only have two
sea cocks that are below the waterline. Engine room cooling water and head
discharge.)

Steve

Sea Cocks
 

"JimB" wrote in message
...

Are your machine screws stainless or other metal? If
stainless, keep an eye out for corrosion under the epoxy.
Stainless doesn't like to be deprived of oxygen, as you
know!


I managed to find monel bolts for these sea cock flanges. ( I only have two
sea cocks that are below the waterline. Engine room cooling water and head
discharge.)

Steve

Sea Cocks
 

On Fri, 9 Jan 2004 08:33:43 -0800, "Steve" wrote:


"felton" wrote in message
I am still pondering. My current disgruntlement probably brought on
by the fact that two of mine are now stuck in the open position, which
doesn't make me happy at all as my boat is in the water over the
winter. Something I have to take care of ASAP.



Shame on you Felton. You should have been cycling those sea cocks every time
you used the boat or at least once a month.. Even the Forspar Marelon valves
have a tag on the handle recommending that they be cylcled monthly and
lubricated annually.

I am generally pretty good about closing all the seacocks when I leave
the boat. I suspect it is not a coincidence that these two are the
hardest to reach, so I may have been less than perfect in this
regard:) For the same reason, they will be the hardest to work on:(

However, I'm afraid I'm guilty of this same neglect.

You should be able to free these valves by loosing the nut on the bottom of
the plug, tap it with a soft hammer (or hammer on a block of wood). Since
the plug is tappered it should come loose from the seat and rotate.. After
operating it though a number of cycles, adjust the nut just enough to
lightly hold the plug in place.

Thanks. I was planning on taking some of my persuaders with me the
next time I go to the boat. I hate leaving those things open.


Steve
s/v Good Intentions

Sea Cocks
 

On Fri, 9 Jan 2004 08:33:43 -0800, "Steve" wrote:


"felton" wrote in message
I am still pondering. My current disgruntlement probably brought on
by the fact that two of mine are now stuck in the open position, which
doesn't make me happy at all as my boat is in the water over the
winter. Something I have to take care of ASAP.



Shame on you Felton. You should have been cycling those sea cocks every time
you used the boat or at least once a month.. Even the Forspar Marelon valves
have a tag on the handle recommending that they be cylcled monthly and
lubricated annually.

I am generally pretty good about closing all the seacocks when I leave
the boat. I suspect it is not a coincidence that these two are the
hardest to reach, so I may have been less than perfect in this
regard:) For the same reason, they will be the hardest to work on:(

However, I'm afraid I'm guilty of this same neglect.

You should be able to free these valves by loosing the nut on the bottom of
the plug, tap it with a soft hammer (or hammer on a block of wood). Since
the plug is tappered it should come loose from the seat and rotate.. After
operating it though a number of cycles, adjust the nut just enough to
lightly hold the plug in place.

Thanks. I was planning on taking some of my persuaders with me the
next time I go to the boat. I hate leaving those things open.


Steve
s/v Good Intentions

Sea Cocks
 

On Thu, 8 Jan 2004 19:03:52 -0800, "Steve" wrote:


"Steve" wrote in message
...

I just wish I had a good online reference to what a proper tapered plug
valve looks like..


OK, here is the best I could do with a quick Google. It is a commercial
TAPERED PLUG VALVE.
http://www.conind.com/pdf/plug%20valve.pdf

Thanks, Steve...that's interesting...I still like my ball valves,
though, but in some inaccessible places, these could be good.

R.