Why doesn't my threaded copper pipe fit a SharkBite reducer?

Question

I have the old 1 inch copper pipes in the basement. I'm about to reduce the size of the pipe into 3/4. So I bought a reducer, SharkBite 1/2 x 3/4 reducer(picture 1). The problem is my pipe size is a little less than 1 inch(picture 2). The outer diameter is 15/16 while 1-inch-copper-pipe at Home Depot is exactly 1 inch(picture 3). I measured my pipe multiple times from the different angles but still it's 15/16. I measured the inner diameter of the SharkBite reducer and it was exactly 1 inch.

Do you think I could still use the SharkBite reducer even the pipe is not exactly 1 inch? I have to know this before cutting the pipe. I need to install a valve right after cutting the pipe without any problem to use the water in the house. Any advice would be appreciated :)

Answer 1

Okay, there is a lot to unpack here.

First

You are reading your calipers wrong. You should be looking at the ZERO on the slider.

First picture shows 1-1/16". Also, you should not be measuring the threads; measure the solid pipe.

Second picture shows 1-1/8"; this is the correct actual dimensions for nominal 1" copper.

Second

Copper tubing does not get threaded; it's not thick enough and doing so would compromise its integrity. That first picture is not copper, it's red brass; nominal 3/4".

Below is a picture of a male adapter (MIP) being sweated onto a copper tube:

Note: this is not what your current situation is.

Third

That SharkBite is unlikely to succeed. Check the packaging for a list of compatible piping. Usually it's "PEX, copper, CPVC, PE-RT, or HDPE Pipe". If your existing pipe is not one of those then you need a different solution.

Conclusion

Do NOT cut that tubing without a proper plan in place. If you cut it then you'll need to manually thread it with some expensive equipment which I assume you do not possess.

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I need to install a valve right after cutting the pipe without any problem to use the water in the house.

This statement scares me. Are you planning to cut the pipe without shutting the water off in hopes of attaching a shut-off valve? I hope you enjoy your new basement pool.

Have fun being this guy: https://www.youtube.com/watch?v=OP30okjpCko

Answer 2

The existing pipe in your photo is threaded pipe, while the photo you took at Home Depot is copper tubing. Copper tubing is manufactured to an outside diameter that is 1/8" larger than the nominal dimension - i.e. 1" tubing is actually 1.125" outside diameter. You'll see that measurement if you look at the zero reference in that photo. Pipe dimensions are also a little odd. For example, a 1" pipe has an outside diameter of 1.315 inches, and an inside diameter that's kind of close to 1 inch, if it's standard thickness (sch. 40).

Since the pipe you need to connect to is threaded, can you unscrew it and install a threaded valve? I'm guessing it's 3/4" pipe, which has an outside diameter of 1.050". You're measuring about 1.0625 which may differ a bit because your measurement is in the threaded portion.

Here is a pipe dimension chart. There are many others available.

And Here is a copper tubing dimension chart.

Answer 3

Copper comes as tubing and as pipe; they have different OD, and wall thickness is different for different "grades" ( K,L,M). Pipe only comes in certain ANSI OD sizes; Wall can vary, such as Sch 40 or 80 or 120. Any pipe of a size ( such as 1 in.) will thread into any other pipe, copper, steel, stainless, etc. Tubing comes in any size a mill and a purchaser agree upon .When I was on the ASTM commitees , they were considered so different that there were two committees, one for pipe and one for tube. They have now been combined. You should be able to figure out what you have from the dimensions of @ Mark.