Galley gray water was backing up into the shower stall and the head sink is not draining quickly enough. Also getting to be a pain draining the compost toilet urine tank every day, and with 4 on board it will be once a day if not more. The solution is to install 3 HepVo drains in the head. One for the sink, one for the toilet and one for the tub, all going into the gray water tank(s). However when opening up the floor, oh shit ! There was no room to install the HepVo valve for just the shower tub.
So this one valve will have to serve both the head sink and the shower to prevent backups. For some reason water from the head sink never backs up into the tub. Weird but true. Side Note: There was no way to get the 1 1/2" sink drain tubing to mate with anything. Gnettie found a 1 1/2" x 1" hose barb fitting that I was able to compression fit into the HepVO valve and direct connect it to the existing hoses! Love it when a plan comes together.	For the urine draining into the gray water I'll have to add a whole new line and hook it into the sink drain hose. To be continued.