Toilet Water Supply Line, what size is it?

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TacoFan

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Hi, I’m in an old house with old shutoff valves. I need to replace my toilet supply line. The shutoff valve outlet size seems like it may be uncommon.

So far I know the water shutoff valve outlet is not:
- 3/8 (way too small)
- 7/16 compression (too small)
- 1/2 compression (too small)
- 1/2 FIP (too big)

The water shutoff valve outlet is 16 TPI male threaded. The water shutoff valve diameter on the threads is about 0.7180”.

I’m attaching some pics including one existing water supply line that is the correct size, currently connected to another toilet water supply shutoff valve.

I know it might be easier to replace the valve. I’d like to keep the original valves if possible. I can’t even find the water shutoff (this house’s plumbing, electrical, and gas are an absolute nightmare), so I’d rather avoid replacing the valve if possible.

Anyone know what I’m dealing with?

D4A5575E-DAB4-4E15-98F3-49C66FE3B069.jpeg

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0F254B17-38A2-4129-8B53-67598DE15482.jpeg

089A9D01-2C44-4A34-BC94-52A8E7E7B251.jpeg
 

Reach4

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I know it might be easier to replace the valve. I’d like to keep the original valves if possible. I can’t even find the water shutoff
Might be time to put in a water shutoff where the city water enters the house.

What is the diameter of that pipe from the wall? My guess would be 0.675 or 0.840.
 

wwhitney

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Doesn't the first picture show some sort of brass adapter between the shutoff valve and the modern supply line? Can't you separate the adapter from the supply line and reuse it?

Cheers, Wayne
 

TacoFan

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Doesn't the first picture show some sort of brass adapter between the shutoff valve and the modern supply line? Can't you separate the adapter from the supply line and reuse it?

Cheers, Wayne

I have two toilets with identical looking shutoff valves and two adapters. One is brass and one is steel. The steel one is too big to fit on one of my shutoff valves.

I just swapped the steel adapter to the toilet that had the brass adapter and found the steel one fits over there! And the brass one fits where the steel one wouldn’t. I think there’s a slight variation in the thread sizes of both the shutoff valves and the adapters. I think the steel one is the wrong size and someone just made it work in the past. And one of the shutoff valves has probably had its threads damaged over time. Basically the brass one works on both toilets and the steel one only works on one toilet.

Anyway, swapped them around and got it working!! Thanks.

Also here’s the measurements for both adapters and the pipe coming from the wall for anyone who is curious.

If anyone knows what the adapter is I’d love to know since the rubber inside the adapters is badly worn out. It’s barely not leaking right now.

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Reach4

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3/8 compression thread is 0.563 od 24 TPI. Your 0.5575 is fairly close to that.
 

Mr tee

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That looks like an old American Standard stop. They had their own uniquely sized SJ nut.
 
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