Can I use dry ice to "unfreeze" my valves?

[Baracus]

@dzero

That would make sense if the smaller size (mass?) of the the smaller pipe meant it couldn’t contract as much. But is that really how it works? I would have guessed that they both would have contracted proportionally. If so, shouldn’t the worst case be that they shrink an equal amount and the tolerance of 3/1000 remains the same?

Let’s simplify things a little bit and say the outer pipe has a inner diameter of 2 and the inner pipe has a outer diameter of 1, meaning there is a 0.5 gap all around. If each one shrinks by half, the outer pipe will have an inner diameter of 1 and the inner pipe an outer diamter of 0.5, leaving a gap of 0.25 all around.

[dzero]

@Baracus

@dzero

That would make sense if the smaller size (mass?) of the the smaller pipe meant it couldn’t contract as much. But is that really how it works? I would have guessed that they both would have contracted proportionally. If so, shouldn’t the worst case be that they shrink an equal amount and the tolerance of 3/1000 remains the same?

Let’s simplify things a little bit and say the outer pipe has a inner diameter of 2 and the inner pipe has a outer diameter of 1, meaning there is a 0.5 gap all around. If each one shrinks by half, the outer pipe will have an inner diameter of 1 and the inner pipe an outer diamter of 0.5, leaving a gap of 0.25 all around.

Weird.

And under heat, 2 goes to 4 and 1 goes to 2 with 1/2 of 4-2 = 1" all around.

How the hell did I get that so fucking backwards? That is genuinely troubling.

Even so, thank you.

[Tim_T-Bonham.net]

@dzero

It was built by a contractor for his own family so I know he used the best of everything available at the time.

That would be unusual. In my experience, contractors building things for themselves/their family tend to use whatever leftover parts happen to be laying around at the shop.

[rjk]

Considering shrinkage/expansion, you could try wrapping the body of the valve in a hot wet cloth and applying dry ice to the tap (or its shaft, if that’s convenient). There might be enough differential to break it loose.

No guarantees, but dry ice is fun anyway.

[dzero]

@tb

That would be unusual. In my experience, contractors building things for themselves/their family tend to use whatever leftover parts happen to be laying around at the shop.

I guess this guy was the exception. For example, all 2x12 beams are 12" on center - everywhere - floor, ceiling, roof. I had to drill though the floor and subfloor to run some wires and I think total thickness had to be at least 4-5". He put in 100amp service in the early 60’s when I think that was pretty uncommon, but I’m not sure. That’s all i can think of now. But on some stuff he probably did cheap out - I just can’t think of an example.

@rjk

Considering shrinkage/expansion, you could try wrapping the body of the valve in a hot wet cloth and applying dry ice to the tap (or its shaft, if that’s convenient). There might be enough differential to break it loose.

No guarantees, but dry ice is fun anyway.

Well, today I took tripolar’s advice and popped the valve handles. Now I can see the valves. They look clean, shiny even. At this point, I’m thinking, screw it, just replace the damn valves. You have to understand that things are kinda cramped. Even with all the crap out of the way, there’s a built-in hamper on one side with maybe 5" of clearance. The drain is right in my face. There’s a shelf in there. Yeah, I know, whine, whine, boo hoo. You’re right. I’m a pussy, but I know for sure I can do the valves - definitely the guts and probably the whole assembly if it comes to that.