Re: Toilets, Y valve or not Y valve
I took out the Y and the Y valve in March this year, and installed new hoses without any T or Y or Y-valves. One hose from head to top of holding tank, Two outlets in the bottom of holding tanks, one to the macerator/seacock via vented loop and the other to deck pump out. The simplest system in my opinion. Handle on seacock always closed (not locked or zip-tied) when sailing in NDZ and keyed switch on the macerator pump with key stored in the cockpit on the key chain together with the engine starter key.
All perfectly legal and no smelling standing sewage in any of the hoses, T's, Y's or valves anymore.
All I can say is: "why did I not think of this before"?