Can I repack the stem of a pressurized globe valve?
Matt
leaks a little around the stem. I have tightened the packing nut a few
times, but it always starts leaking again pretty soon. The valve shuts
off the flow /through/ the valve pretty well though.
I don't want to have the city come out and shut off the water from the
outside. I don't even know if their valve still works, as I don't know
that they have operated it in about 40 years.
So I want to repack the stem with the valve closed and the line under
pressure. Will that work okay?
It is a Nibco 3/4" NPT right-angle bronze globe valve from the late
1960's. Where can I find replacement packing? Will it be a rubber
washer or what?
Thanks.
Oren
<ma...@themattfella.xxxyyz.com> wrote:
>The main water shutoff valve inside my house is a globe valve, and it
>leaks a little around the stem. I have tightened the packing nut a few
>times, but it always starts leaking again pretty soon. The valve shuts
>off the flow /through/ the valve pretty well though.
>
>
>I don't want to have the city come out and shut off the water from the
>outside. I don't even know if their valve still works, as I don't know
>that they have operated it in about 40 years.
>
>
>So I want to repack the stem with the valve closed and the line under
>pressure. Will that work okay?
>
>
Do you feel lucky? You don't say where the valve is located: garage,
basement, etc...
You can buy valve stem packing (rope) in small packages at a local
hardware store.
Are you really sure you want to remove the bonnet nut with the water
on? If the city breaks their shutoff valve they fix it, ime.
George
> The main water shutoff valve inside my house is a globe valve, and it
> leaks a little around the stem. I have tightened the packing nut a few
> times, but it always starts leaking again pretty soon. The valve shuts
> off the flow /through/ the valve pretty well though.
>
>
> I don't want to have the city come out and shut off the water from the
> outside. I don't even know if their valve still works, as I don't know
> that they have operated it in about 40 years.
Its their problem if it doesn't. Now would be the time to find out.
Stormin Mormon
before removing the handle and packing nut. No luck
required, there.
The Home Depot near me sells packing stuff. Some kind of
silicone treated rope, that goes around and around. I'd wind
it clockwise, so the packing nut will pull it tighter.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"Oren" <Or...@127.0.0.1> wrote in message
news:atdek61r1hbq0f1rg...@4ax.com...
Stormin Mormon
off. Or, call the water people in the spring when they can
dig it up if needed.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"George" <geo...@nospam.invalid>
wrote in message
news:ii7fbh$5ea$1...@news.eternal-september.org...
GROVER
Others have cautioned about removing the valve bonnet while system is
under presssure. I would add the following information. The rope used
for packing is called oakum and is hemp or jute rope infused with oil
or tar. Its other use is to caulk open seems of wooden ships.
Joe G
Matt
> Are you really sure you want to remove the bonnet nut with the water
> on?
I think I am sure I don't want to do that.
I want to remove the packing nut, not the bonnet nut. The valve looks
sort of like the following, only not as tall:
http://t3.gstatic.com/images?q=tbn:ANd9GcRne_9OYpl4NGuSDiRC9rJDv8-mfp5JN5jMMluQtJaSPOggM5xhlQ
in that the packing nut seems to be separate from the bonnet nut.
Here is what I hope/expect the cross section looks like:
http://t2.gstatic.com/images?q=tbn:ANd9GcTcmMiANYTJrRJepPSUPqAvlRZngyTGv8zHIkFgscQV49Gzw8jO
The valve to be repaired would be closed, but there would still be
pressure on the upstream side of it. It looks like the packing doesn't
need to do much when the valve is closed.
Now what do you think?
Vic Smith
Valve packing is infused with graphite, or something close.
I don't know the material that makes up the strands.
High pressure packing like I used in the Navy is wire reinforced.
We cut rings, didn't wind it. Offset the ring gaps about 1/3rd the
stem circumference.
Packing width had to be matched to the stem-to bonnet wall exactly.
It was standardized though 1/4", 5/16:, 3/8th though, so it didn't
take much thinking.
I've had more problems packing home hose faucet stems with the odd
size stuff from the hardware stores than sealing 1300 psi steam valves
in the Navy. Maybe because I wind it.
Seems to stop it from leaking you end up with a stiff valve.
You should probably measure what width packing the valve needs, and
cut rings.
Valves are cheap. Next time my hose faucet stem starts leaking I'll
put in a new valve.
Oakum packing uses some kind of tar, and is also used on steel ships
with riveted hulls.
When I was in the Merchant Marine and watertending on the Rocket, a
Cleveland Oil tanker, the Skipper had us dead in the water in the
middle of one of Great Lakes, can't remember which.
He put on scuba gear and went over the side with oakum and whatever
driving tool you use for that.
I heard there was a leak in one of the plates.
Maybe he was showboating, but it's good to have a Skipper that can
do "things" like that.
I wouldn't try to pack a valve with pressure on it, but you might get
away with it.
--Vic
Oren
<ma...@themattfella.xxxyyz.com> wrote:
>On 01/31/2011 04:37 PM, Oren wrote:
>
>> Are you really sure you want to remove the bonnet nut with the water
>> on?
>
>
>I think I am sure I don't want to do that.
>
>I want to remove the packing nut, not the bonnet nut. The valve looks
>sort of like the following, only not as tall:
>
>http://t3.gstatic.com/images?q=tbn:ANd9GcRne_9OYpl4NGuSDiRC9rJDv8-mfp5JN5jMMluQtJaSPOggM5xhlQ
>
>in that the packing nut seems to be separate from the bonnet nut.
>
>Here is what I hope/expect the cross section looks like:
>
>http://t2.gstatic.com/images?q=tbn:ANd9GcTcmMiANYTJrRJepPSUPqAvlRZngyTGv8zHIkFgscQV49Gzw8jO
>
>
>The valve to be repaired would be closed, but there would still be
>pressure on the upstream side of it. It looks like the packing doesn't
>need to do much when the valve is closed.
>
>
>Now what do you think?
>
I think we call a bonnet nut and a packing nut the same thing.
Wrap the stem with packing rope, pack it in and put the bonnet/packing
nut back on.
Please do turn off the water, first.
Just my thinking...
Matt
> Gee, whiz. I thought everyone knew to shut off the valve
> before removing the handle and packing nut.
I do intend to close the valve, if that is what you mean. I don't see
that removing the packing nut causes a leak as long as the valve is
closed, even if the upstream side is under pressure. The stem would
remain screwed into the bonnet and hold the valve closed during
repacking, unless I am wrong.
I would: remove the handle to loosen it, then put the handle back on
loosely, close the valve tightly, loosen the packing nut, see that the
valve is still closed tightly, remove the packing nut and the handle,
remove the packing, put in the new packing, replace the packing nut,
replace the handle, open the valve, tighten the packing nut as needed to
stop leaks.
Does that make sense?
Matt
> On Mon, 31 Jan 2011 20:36:37 -0600, Matt
> <ma...@themattfella.xxxyyz.com> wrote:
>
>> On 01/31/2011 04:37 PM, Oren wrote:
>>
>>> Are you really sure you want to remove the bonnet nut with the water
>>> on?
>>
>> I think I am sure I don't want to do that.
>>
>> I want to remove the packing nut, not the bonnet nut. The valve looks
>> sort of like the following, only not as tall:
>>
>> http://t3.gstatic.com/images?q=tbn:ANd9GcRne_9OYpl4NGuSDiRC9rJDv8-mfp5JN5jMMluQtJaSPOggM5xhlQ
>>
>> in that the packing nut seems to be separate from the bonnet nut.
>>
>> Here is what I hope/expect the cross section looks like:
>>
>> http://t2.gstatic.com/images?q=tbn:ANd9GcTcmMiANYTJrRJepPSUPqAvlRZngyTGv8zHIkFgscQV49Gzw8jO
>>
>>
>> The valve to be repaired would be closed, but there would still be
>> pressure on the upstream side of it. It looks like the packing doesn't
>> need to do much when the valve is closed.
>>
>>
>> Now what do you think?
>>
>
> I think we call a bonnet nut and a packing nut the same thing.
But I think you can see, from the pictures I linked to, that they are
not the same thing.
Oren
<ma...@themattfella.xxxyyz.com> wrote:
>On 01/31/2011 08:59 PM, Oren wrote:
>> On Mon, 31 Jan 2011 20:36:37 -0600, Matt
>> <ma...@themattfella.xxxyyz.com> wrote:
>>
>>> On 01/31/2011 04:37 PM, Oren wrote:
>>>
>>>> Are you really sure you want to remove the bonnet nut with the water
>>>> on?
>>>
>>> I think I am sure I don't want to do that.
>>>
>>> I want to remove the packing nut, not the bonnet nut. The valve looks
>>> sort of like the following, only not as tall:
>>>
>>> http://t3.gstatic.com/images?q=tbn:ANd9GcRne_9OYpl4NGuSDiRC9rJDv8-mfp5JN5jMMluQtJaSPOggM5xhlQ
>>>
>>> in that the packing nut seems to be separate from the bonnet nut.
>>>
>>> Here is what I hope/expect the cross section looks like:
>>>
>>> http://t2.gstatic.com/images?q=tbn:ANd9GcTcmMiANYTJrRJepPSUPqAvlRZngyTGv8zHIkFgscQV49Gzw8jO
>>>
>>>
>>> The valve to be repaired would be closed, but there would still be
>>> pressure on the upstream side of it. It looks like the packing doesn't
>>> need to do much when the valve is closed.
>>>
>>>
>>> Now what do you think?
>>>
>>
>> I think we call a bonnet nut and a packing nut the same thing.
>
>
>But I think you can see, from the pictures I linked to, that they are
>not the same thing.
>
>
Well then here is a picture calling it a bonnet nut.
Imagine that. Not your valve, but it really is a bonnet nut.
Matt
>
> I wouldn't try to pack a valve with pressure on it, but you might get
> away with it.
>
> --Vic
I will look for packing rope of a diameter the same as the gap between
stem and bonnet wall.
If I cut rings, should their lengths all equal the circumference of the
bonnet wall? Or maybe the circumference of the middle of the gap? Or
something else?
I guess I would cram the rings down the bonnet one at a time using the
edge of a PVC coupling of an appropriate diameter. Is that
approximately how you would do it?
Vic Smith
<ma...@themattfella.xxxyyz.com> wrote:
>
>If I cut rings, should their lengths all equal the circumference of the
>bonnet wall? Or maybe the circumference of the middle of the gap? Or
>something else?
>
You ''ll see the length to cut when you wrap it around the stem.
Problem is the high pressure packing I used in the Navy was square in
cross-section, and I don't think you'll find that for your valve.
Try to get packing that's a tight fit between stem and bonnet wall.
when you wrap it around the stem.
Mark it with a knife/razor so the ends butt with no gap when you put
in the ring, then cut it and put it in.
Even with round coss-section packing, it should work.
I had to cut the wider high pressure stuff at an angle to get a clean
butt, but you shouldn't have to worry about that with the soft packing
you're using.
>
>I guess I would cram the rings down the bonnet one at a time using the
>edge of a PVC coupling of an appropriate diameter. Is that
>approximately how you would do it?
That's good thinking. Any tube that fits well will work.
Push it down, then tap it lightly with a hammer.
You'll be tapping on the gland at the other end of what tube you use.
The valves I worked with all had split packing glands, and I would put
in a ring and push it down with the gland.
Next ring, or third ring would require putting an open end wrench on
top of the gland and rapping them down by whacking the wrench with a
hammer.
Don't know what kind of gland is on your valve.
You'll find it under the gland nut.
Probably a solid gland, like a bushing.
Seat each ring well using the gland.
Don't put so much packing in that the gland nut can only grab a few
threads.
You don't want to strip it.
--Vic
Vic Smith
<thismaila...@comcast.net> wrote:
>On Mon, 31 Jan 2011 22:49:58 -0600, Matt
><ma...@themattfella.xxxyyz.com> wrote:
>
BTW, I still don't recommend repacking with pressure on the line.
Might be okay, might not.
I've noticed with these small valves that the stem to body threads are
a pretty sloppy fit.
I think the packing around the stem gives that fit stability.
It's possible that pulling the packing will allow the movement of the
stem and let the disk move on the seat.
Just a "feeling."
You're going to need scribes to pull the old packing with the bonnet
on. We called them scribes anyway.
Something like this
http://www.amazon.com/Trademark-Machinists-Scribe-Double-Degree/dp/B004ANNA0A
But I got a better set somewhere else for about 5 bucks.
Can't remember where.
--Vic
Stormin Mormon
I'd be tempted to pull the handle. Dab of grease between the
handle and the shaft. Slip a box wrench over the bonnet.
With the handle back on, keep a bit of turning pressure on
the handle, loosen the bonnet with the other hand (box
wrench, maybe?). That way you are fairly sure the rotating
bonnet doesn't rotate the shaft, and open the valve. Just me
being over cautious.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"Matt" <ma...@themattfella.xxxyyz.com> wrote in message
news:zLK1p.7040$zb7....@newsfe08.iad...
Matt
> On Mon, 31 Jan 2011 23:20:27 -0600, Vic Smith
> <thismaila...@comcast.net> wrote:
>
>> On Mon, 31 Jan 2011 22:49:58 -0600, Matt
>> <ma...@themattfella.xxxyyz.com> wrote:
>>
>
> BTW, I still don't recommend repacking with pressure on the line.
> Might be okay, might not.
> I've noticed with these small valves that the stem to body threads are
> a pretty sloppy fit.
> I think the packing around the stem gives that fit stability.
> It's possible that pulling the packing will allow the movement of the
> stem and let the disk move on the seat.
> Just a "feeling."
I hadn't thought of that. Maybe I'll loosen the packing nut and try to
wobble the stem to get an idea of how tight the fit is. If I get
sprayed or get a wad of packing up my nose, I'll know the stem is way
too loose to do the operation. :-) At worst I will have to put it
back together, close the valve, and go without water while waiting for
the city to come out and shut their valve.
> You're going to need scribes to pull the old packing with the bonnet
> on. We called them scribes anyway.
> Something like this
> http://www.amazon.com/Trademark-Machinists-Scribe-Double-Degree/dp/B004ANNA0A
> But I got a better set somewhere else for about 5 bucks.
> Can't remember where.
>
> --Vic
Thanks for the tips, Vic.
Matt
> On Mon, 31 Jan 2011 22:49:58 -0600, Matt
> <ma...@themattfella.xxxyyz.com> wrote:
>> I guess I would cram the rings down the bonnet one at a time using the
>> edge of a PVC coupling of an appropriate diameter. Is that
>> approximately how you would do it?
>
> That's good thinking. Any tube that fits well will work.
> Push it down, then tap it lightly with a hammer.
> You'll be tapping on the gland at the other end of what tube you use.
> The valves I worked with all had split packing glands, and I would put
> in a ring and push it down with the gland.
> Next ring, or third ring would require putting an open end wrench on
> top of the gland and rapping them down by whacking the wrench with a
> hammer.
Maybe you guys cut the packing into rings because you can't use the
gland to press a coil one loop at a time.
But I guess I could press a coil a little at a time if I used a tube
that had a section cut out of its circumference. What would you think
of that?
Vic Smith
<ma...@themattfella.xxxyyz.com> wrote:
>
>Maybe you guys cut the packing into rings because you can't use the
>gland to press a coil one loop at a time.
>
The gland is too tight a fit to allow any packing to stick out, so
that rules out spirally it. The cut rings with staggered gaps worked
fine. I'm not an engineer, just followed the established practice.
>But I guess I could press a coil a little at a time if I used a tube
>that had a section cut out of its circumference. What would you think
>of that?>
Neat idea. Like a weed whacker string.
As I recall packing the few home valves I've done, I would spiral what
I could around the stem, pushing as much into the body as I could,
then would snip it and use the gland to push it down, then repeat the
process, probably just once.
Always fixed the leak, but I always thought the valve turned harder
than I like.
But the last one I did, maybe 5 years ago, the front garden faucet,
turns easily now, so maybe the stem just has to wear into the packing.
Hey, I think you know more about packing valves than me now.
Good luck, and be careful You don't want a flood.
I dealt with a similar situation when I re-piped the galvanized in my
last house, a 2-flat. Stuff was about 50 years old.
Water flow to the faucets was getting real poor.
Shut off the city water valve myself, a gate valve under a small
manhole cover on my front lawn.
It was very stiff and I figure scaled up. I worked it opened and
closed maybe 10 times trying to stop the flow to the basement sink.
The main valve in the house that you're working on
was cranked down tight too, but leaking through.
Same flow whether it was opened or closed.
All other valves in the house were open.
Best I could do was get it down to a weak stream in the sink.
I had a new house shutoff valve with nipple ready to attach to the
lead service pipe when I took it apart.
Taped and with the valve open.
Had a buddy sitting on the floor holding a washtub to catch the water.
When I broke the union after the valve he caught the same small stream
that had been going into the sink, and I moved that pipe out of the
way.
Then I cranked the old valve and nipple off the lead pipe.
It was like a fire hose had been opened.
He was facing it and put the washtub up like a shield to protect his
face.
I got the new valve/nipple on pretty quick and shut the valve.
If the valve wasn't open it wouldn't have gone on.
We got pretty wet and probably lost a few gallons of water on the
floor. Having the new valve ready to crank on was important.
My point here is if the pipes are scaled up it hard to know how bad
the city valve is leaking through.
I was really surprised with the volume and pressure I got from the
city feed. Closing that city valve was almost useless.
Didn't have much travel, so I probable never got it but half closed.
But I didn't want to break it and have to call the city out.
The pipe I replaced was scaled bad. The 3/4" maybe down to 1/2"
Hot water was much worse. At the joints it was barely open
--Vic