Just thought I would throw this out there to help someone else possibly. Most times when I had to start my AC for the first time I would always have to go and remove the discharge hose, get sprayed with water once it primed and than hope it didn't happen anymore. I am working on my boat on the hard in prep for 2020 season(long story) and just going thru all systems. I installed this valve to ease the priming problem. All plastic parts and it worked perfectly when tested. Hope this helps someone else out.