This is a sleeve that lets you freeze a pressure-tight plug in a pipe so you can repair/modify downstream plumbing.
https://www.youtube.com/watch?v=nUo0Mr5fTvA
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This is a sleeve that lets you freeze a pressure-tight plug in a pipe so you can repair/modify downstream plumbing.
https://www.youtube.com/watch?v=nUo0Mr5fTvA
Looks like they are putting the kibosh on it......
The refrigerant is often CO2 or other pollutant.
Ralph
It says in the video that it uses HFO-1234ze.Quote:
Originally Posted by Ralphxyz
I spent 3 years of my time on active duty US Navy, setting up and operating freeze seals on nuclear piping systems aboard various classes of submarines and Guided Missile Cruisers. We use liquid nitrogen in large, "portable" tanks called "dewers." Originally, it was done with 2 piece copper jackets that clamped around the pipe. One set would be placed on the pipe, either side of the system component we were to work on. These jackets had to be inspected and hydrostatically tested, before every use. They were kind of a pain because of all of the storage requirements and paperwork involved. Heaven forbid one of them didn't pass inspection! We eventually switched over to using coils of new, heavy wall, seamless, coper tubing. It became disposable after use, so the inspection part went away. We ran the liquid nitrogen to each coil directly from the tank and throttled it with cryogenic needle valve after it left the freeze coils on the pipe. That way, it picked up as much heat as possible and we were able to maintain a temp of around -326 degrees Fahrenheit. We had so many monitor points, that I think we made NASA jealous. We used brass nuts and ferules on 316 series stainless steel bodies for our compression fittings. We did this combo because it prevented any risk of the galling that is common with stainless steel. The pipe outside diameters were measured in the same spots before and after the freeze was done. We also had to have all the pipe insulation we installed, tested for it's chemical content for any chloride content because some of the materials used in nuclear powerplants are susceptible to chloride stress corrosion, and that can lead to catastrophic failure of the material.
Did you recover the liquid Nitrogen or just let it waste to the atmosphere? As a residential plumber we used to use CO2 that was just wasted.