under sink shutoff won't come off

I have an older oblong-valve type undersink shutoff that I'm trying to replace. I got everything disconnected except the hot water inbound connection. I am turning and turning and turning the thing, and it's going around and around, but it's not coming off. taped a little tab around the pipe, and it hasn't moved, so I know I'm not twisting the pipe. Is there something else I have to do to get that off?
I'm assuming I can't just Dremel it off and using the bare pipe because the shutoff valve input there is threaded.
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Adam Preble wrote:

Adam, It sounds like you are talking about galvanized pipes. If this is the case, you might have rusted threads due the dissimilar metals at the connection. If you can access the next knuckel down the line (the other end of the pipe) try removing the pipe and replacing it also. Hope this helps.
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Or it could be a compression fitting. Hold the valve body with a wrench, and rotate the nut with another wrench. I forget which way to rotate, but it'll become obvious. I think. Tom
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On Sun, 22 Jan 2006 23:41:12 GMT, Adam Preble

Sounds as if it may be a compression fitting- if so hold the valve and back the nut off the valve. Nut and ferrule will remain on pipe.
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snipped-for-privacy@totally.invalid wrote:

That seems a little strange to me. The shutoff I'm trying to remove looks like the kind I was recommended at Home Depot (this post goes downhill now). For the replacement on hand, the main nut on that shutoff doesn't turn independently of the body.
Assuming this is the case, should I get a different shutoff valve? Also, it was asked within the thread somewhere what the metals were. It's a copper pipe with a brass valve.
I just want to make sure before I start on that because I've since put everything back together, and it gets to be pain in the but to turn off the main, take off the disposal, move the PVC pipe around, and then do that all in reverse to put together again.
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You are talking about angle stops. Choice 1= straight or el? Choice 2=what size line going to sink? Choice 3=what size pipe are you stopping? Once you've gotten this far, you only have a few more choices:
There are at least 3 different shut off valves that look just about alike. The ones that I'm talking about only differ in how they fasten to the existing supply pipe.
If the existing supply is copper, it will either be compression or sweat fitting. If it is a sweat fitting (doesn't sound like it) it will not turn or unscrew at all, it is soldered to the pipe in the wall and you will either break the fitting, the solder joint, or twist the pipe. It sounds like your existing valve is a compression valve. It will have external threads with a proprietary cap nut. The cap nut and valve have a ferrule between them that is squashed onto the supply pipe. You will probably not be able to remove the existing cap nut or the ferrule unless you cut off the end of the pipe because you cannot pull the ferrule off. If the problem was not with the cap nut or ferrule, you should leave them on the pipe and reuse them on your new valve. If you have bought the wrong valve, go back to the store and buy the correct one. If the existing supply is threaded pipe/threaded copper/thread adapter for PEX, etc it will be internally threaded and identified on the package as F.I.P (female iron pipe) If it is fip it will come off with your wrench as it unscrews from the threaded end of the pipe.
(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net
wrote:

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Adam Preble wrote:

I think you are getting yourself in too deep if you can see how to get the valve off. But to clarifiy, if the supply pipe end with a formed nut (flats for a wrench), then the valve screws onto the pipe. If the supply pipe has no nut, then it is a compression fitting and if you look at one in the store you will see how it fits--you hold the valve with a wrench and turn the nut on the end away from the handle, then it slides off the supply pipe leaving a brass ring and the nut. Then you remove the compression ring, slide off the nut, and, if you are smart, you cut off about an inch of the supply pipe so the new compression ring is on a virgin surface, and install the new valve.
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George E. Cawthon wrote:

Had I still had everything ready to go, I would have tried pulling it off as recommended here already. The problem then would have been getting a new valve at that time of night that was prim and proper. I'm guessing I'll just get a few valves from Home Depot and return the rest--the "alternater belt strategy."
I've had some limited experience with a compression fitting. The faucet is using copper pipe to go into the main, and the current valve is using a compression fitting. I figured this out after loosening it awhile, getting it off, and then trying to figure out why I couldn't remove the nut. I could see how if that was grimed up enough, the whole valve body would want to turn rather than the nut. So I'll try with two wrenches tomorrow after I get at least one different valve.
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IF the fitting is a compression fitting, the nut could be captured on the tube by a compression ferrule the was been crimped onto tube by the compression nut.
Hope that makes sense.
I ran into a similar situtation where the shutoff valve had an integral conpression fitting. The valve need to be replaced. The nut (captured in place by the crimped ferrule) was pretty much flush with the drywall. I shoved the nut out of the way (back into the drywall), cut the ferrule off & sweat a stub w/ a male thread adapter.
cheer Bob
George E. Cawthon wrote:

Had I still had everything ready to go, I would have tried pulling it off as recommended here already. The problem then would have been getting a new valve at that time of night that was prim and proper. I'm guessing I'll just get a few valves from Home Depot and return the rest--the "alternater belt strategy."
I've had some limited experience with a compression fitting. The faucet is using copper pipe to go into the main, and the current valve is using a compression fitting. I figured this out after loosening it awhile, getting it off, and then trying to figure out why I couldn't remove the nut. I could see how if that was grimed up enough, the whole valve body would want to turn rather than the nut. So I'll try with two wrenches tomorrow after I get at least one different valve.
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BobK207 wrote:

I think so, but I can't even get the valve off right now. Given how the nut is right now, I don't think I'd want to reuse it if it is a separate nut after all.
I took a second look underneath as best as I could; I had the disposal and everything else in the way. The valve body has corroded a lot, and I can't tell if that nut can turn on its own. I did a quick test with my two robogrip pliers, but the smaller one didn't have the spunk to turn the nut. Tomorrow, I'll hold the valve in place with my crazy plumbing wrench and try again.
Since I started screwing around with it earlier, it has begun to leak. I have a 14 quart bucket underneath there that should turn it over overnight. But now I'm getting mad at it.
I have a good 6 inches of copper pipe coming out through the rear cabinet wall, so I'm tempted to cut the current valve off and install a new one with a compression fitting. I know I can't go on doing that kind of thing forever, but I can always extend it back out later if I find myself cutting again. Will this work?
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have a good 6 inches of copper pipe coming out through the rear cabinet wall, so I'm tempted to cut the current valve off and install a new one with a compression fitting. I know I can't go on doing that kind of thing forever, but I can always extend it back out later if I find myself cutting again. Will this work?
If you got the room to do it, I'd suggest cutting the bad stuff & sweating on a male threaded adapter. Those compression fittings are quick & easy but threads are more (IMO) dependable / repairable.
cheers Bob
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OK, I ended up putting on a compression fitting to a male threaded adapter. I was a moron and put the fitting on wrong the first time. I got it to about where I figured it should go and then started to screw everything else on. I now lost that fitting, but I had bought a spare! That was a pain in the butt, but the shutoff works now.
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Adam Preble wrote:

Hey, how else do you learn? If it doesn't leak, you are lucky! It takes some of us a long time, unfortunately. I found that when you put the valve on the pipe and start tightening the nut, you do not want the valve to turn the least bit, just the nut should turn. Some times the valve turning doesn't cause a leak but to be absolutely sure every time, you need to hold the valve so that it doesn't turn. Cheers, and good education.
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