Need help removing a WC supply valve (is it soldered? or something else)

Submitted by nill0c t3_1154hpz in DIY

I’ve got an older supply valve where the rubber seal has failed and the threading on the valve stem is nearly gone. Big box replacement stems don’t fit.

I’m happy to replace it, but I’m not sure how it’s bonded to the pipe.

Here are pictures of the old valve and a replacement valve.

The pipe is chromed copper (I think) and is 11/16 but necks down to 5/8 which matches the 3/8 replacement valve’s ID (because plumbing sizes are silly). It disappears into a tight tile hole in the wall with no other exposed joints. I was thinking of cutting it off and using a shark bite, but it wont fit that sized pipe that I can find. I’m fine sweating it off and replacing too.

No brand markings are visible and none of the plumbing stores nearby had seals of right dimensions. (3/8 ID 5/8 OD 1/8 thick) at any rate, the stem’s brass treads have corroded and mostly crumbled off. There’s just enough to keep the valve closed with the OK seal at the tip of the stem, so luckily we have water, but no flushing upstairs.

I’d be happy just replacing the stem if I could find one, the body of the valve and gland nut all look great and the internet threads are fine too. I just haven’t been able to identify it.

UPDATE: No luck with the torch, heated it up nearly glowing and no budge. I'm really curious how it's bonded or pressed in there at this point. Can't wait to cut it in half when it's out.

I've got a combination of compression fittings/caps that close off the old valve so we can flush the toilet for now. There's a slow drip (since it's not compressing anything, but it's better than it was with the crusty valve stem seal. I'm a little tempted to get some pipe dope on there and fix it "forever".

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Diligent_Nature t1_j90z4do wrote

That is a soldered connection. The O.D. of 1/2" copper pipe is 5/8".

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nill0c OP t1_j929061 wrote

I was hoping that too, and got a replacement valve already, but heating the old valve isn’t melting anything and not budging.

Is it possible it’s a press fit like https://www.homedepot.com/p/BrassCraft-1-2-in-Sweat-Inlet-x-3-8-in-Compression-Outlet-Multi-Turn-Angle-Valve-with-5-in-Extension-Tube-Bell-Flange-CS40BX-C1/202047063 ?

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ianryeng t1_j95inxa wrote

Turn off the water to the house then open the valve then turn on a cold water faucet somewhere lower to get the water out of the line. If this is not possible keep the valve open and be prepared for the water in the copper line to have to boil off partially before the solder will melt. MAP gas helps as well since it burns hotter in the “water in the line” scenario

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nill0c OP t1_j97b5us wrote

Oh yeah, should have updated I’ve had the water off and taken apart the valve, mapp gassed it (even though Mapp gas isn’t what it used to be) and laid heavy foil around the toilet and wall so I could really get it hot.

Pretty sure its not soldered in any way I’ve ever seen (I’ve replaced a water heater and pump tank that both needed cutting and sweating to install).

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Most-Region8151 t1_j91t54z wrote

Try and unsweat it. That little neck'd down pipe might be a pita and have to be replaced.

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nill0c OP t1_j928fz1 wrote

Yeah it would mean cutting out an access hole in the bedroom behind it.

I heated the hell out of it and it didn’t budge. Im thinking it’s like this https://www.homedepot.com/p/BrassCraft-1-2-in-Sweat-Inlet-x-3-8-in-Compression-Outlet-Multi-Turn-Angle-Valve-with-5-in-Extension-Tube-Bell-Flange-CS40BX-C1/202047063

I’m not sure why anyone in their right minds would install something like that though. It’s impossible to service, and makes replacement a mess.

The walls of the chrome pipe are super thin too.

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quackdamnyou t1_j92dayz wrote

Can you just cut it off with a compact pipe cutter, and replace it with a compression valve?

see this thread

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nill0c OP t1_j939wm7 wrote

That would work if there was an 11/16 compression fitting out there. The problem is that the only part of the exposed pipe that's 5/8 (1/2 inch) is mostly stuck in the valve.

I think my new solution might be cutting it off as far from the wall as possible, then I'm pretty sure the remaining pipe will slip fit over 1/2 copper. So I can then sweat in a regular copper pipe (which I'm pretty sure how it's attached inside the wall), and attach a standard valve to the new 1/2 pipe.

It's a bit risky because I don't know the ID of the pipe I'm cutting, but it feels really thin (and already dented easily when I was monkeying around early on).

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quackdamnyou t1_j93c6if wrote

Must be prepared to dig in through that closet if it comes to it.

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nill0c OP t1_j97c8ny wrote

Id be happy to if it was a closet, it’s the the corner of a bedroom wall with no good way to hide a hole without drywall and paint.

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