"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

"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

"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

"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

"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

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

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

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

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

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