In my case valve split apart when I was trying to unmount it. I had to drill a couple of holes and put some screws in to stop rotation and finally remove the valve.
Watch video How to disassemble stuck fitting or valve online, duration hours minute second in high quality that is uploaded to the channel Nikolay 06 January 2021. Share the link to the video on social media so that your subscribers and friends will also watch this video. This video clip has been viewed 9,843 times and liked it 35 visitors.