You posted this and 3 pictures in 2017
#22 I got my valve done today. I just didn't like the ball valve and was able to use a 1.5" slide valve and a 90 at a 45 degree angle toward the opening. This seemed to take up less room that I use for hose storage and take some stress off the hose..
I have a 2019 Seneca FS and the 1.5 inch fitting coming from my macerator appears to be a PVC socket on one end with a barb on other. It is glued on with little room to cut fiting and glue on more. I see several comments from 2016's where it had threads from macerator can you confirm or provide details.