Some years ago during my training, I had used a tool for purging systems, especially domestic A/C where people would turn units on their side and oil would seep into the lines.
This tool would allow me to cut a line completely, and by placing this tool over the line; threading together with a gasket between would create a seal that could hold several hundred psi, on the end being a standard fitting to hook up gauges for a nitrogen purge.

Anyone ever use one, know about it, what its called? Ive tried several searches online but cant find anything that resembles them. Came as a kit for all common pipe sizes.

Thanks