Is this soldered or compression shutoff valve (in the picture)?

And I assume it's connected to 1/2-in copper inlet pipe. All other inlet in house are 1/2-in copper but maybe this isn't as it was re-modeled separately. But I'm confused - what is the white(ish) material on the inlet pipe?

enter image description here

Currently, I've attached a T-vavle to connect hot water bidet tubing, as you see in pic.

My goal is - to change the entire shutoff valve for SharkBite 1/2-in x 3/8-in Od comp Dual shut-off valve. And connect the bidet with a robust 3/8-in compression tubing.

Thank you for your time.

  • You should change the question to "How do I replace this old valve" ... and move your last paragraph to the beginning. That is EASY to answer. I'm going to answer THAT question now. Identifying the white stuff isn't critical. Let's just say it's "gunk".
    – jay613
    Dec 10, 2023 at 20:56
  • 1
    The valve to inlet pipe looks soldered. The white stuff is probably paint/drywall mud/other stuff a not neat person slapped on.
    – crip659
    Dec 10, 2023 at 20:56

1 Answer 1


Look on youtube at how plumbers use abrasive cloth or paper to clean pipes in place. Remove the plastic escutcheon and clean up the stub of the pipe as best you can with the old valve still in place. Doesn't matter what the gunk is .. probably paint ... just scrape it off.

The old valve is soldered on. Saw it off as tight to the solder joint as possible. Then clean up the pipe again, thoroughly and completely this time. Deburr the cut end, and shove your new valve on.

If you are using Sharkbite, they sell a combination tool that deburrs and lets you mark correct insertion depth on your pipe. Buy it and use it! Read their instructions and you'll get a good result.

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