Originally Posted by summercamp
I am getting ready to replace the holding tank system on a new purchase
set up has a Y-valve separating overboard discharge and tank. From the tank the discharge hose goes first to a manual diaphragm
pump and then to a wast deck fitting.
Is this type of arrangement still used and are there any merits to having a pump that empties the tank to a waste deck fitting?
A Y-valve is quite common, and I've seen plenty of manual pumps in place for overboard discharge, but never one that pumped up to the deck plate. You sure about that? Normally a pump out station has a strong vacuum pump that draws the waste up through the deck plate so there is no need for a pump in this side of the plumbing
For over board discharge a very good arrangement, and one that is being used on many new builds, is a gravity dump. To do this the tank is installed above the water
line and to empty it you just open a discharge valve. Less complicated plumbing
and no pumps to maintain. Certainly an option to consider in your replacement install.
A very clean and simple gravity dump installation
is just to plumb head
direct to tank and tank to discharge valve. When inland/near coastal discharge valve is closed. When offshore
valve is opened. Nice simple set-up and simple is good -- I've seen some real plumbing nightmares on waste systems.