86 28' Voyager black water tank overflow

[Bobert]

I have a 1986 Carver Voyager 28' with an OEM Raritan head, mascerator and holding tank installation.
I can see how some of the hoses are routed including what I believe to be the pump out hose.
There is one hose I can see in the bilge that exits at the bottom stern with a valve.
I can't see anywhere a 'Y' valve in the system. There is a hose that passes under the galley.
So, what happens? When the holding tank fills up, does the excess get 'automatically"
directed to the hose outlet in the stern and go overboard?
Would appreciate help in learning how this installation works.

[tomschauer]

There should not be an "overflow" for the holding tank. If it is indeed an overboard discharge, there has to be a Y valve somewhere. Is the hose and valve you are talking about 1 1/2" or is it a smaller line such as 3/4? If its 3/4" it could be the water to the head.

[Bobert]

Thanks, Tom for the reply.
I've got a picture downloaded but don't know how to put it on here.
All the hoses are 2 inch that are under the floor,
2 hoses disappear under the galley under the floor with no apparent
access to view. Pulled out the drawers-- just floor. There is no Y valve
to be seen aft of the bulkhead.
My email is nessasiv@aol.com if you email me I'll send you a picture.

[tomschauer]

Look under the text box. You will see a button labeled "add files" use that to attach pics.

[Bobert]

Well, fancy that!!??
There's the file/picture name.

carver bilge head.jpg

[km1125]

A little hard to tell from that pic. Looks like there's elbows in the lower hose and either a "T" or a splice in the top hose.

The hoses from the heads should go to the top section of the tank, and the hoses to the dockside pumpout and the overboard discharge mascerator should be connected to the bottom of the tank. I would think there's a hose from the bottom of the tank to a mascerator then to a seacock then to the thru-hull. In this case, no "Y" valve is necessary, you just periodically "dump" the tank.

If there was a "Y" valve, it would be between the head and the tank, so the head could pump directly overboard without filling the tank.

[Midnightsun]

On all my 3 previous boat the macerator had no Y valve. It is connected directly to the bottom of the tank via a dip tube from the top of the tank and when activated, it pumps overboard. A Y valve is more suitable to flush overboard directly however some macerators are set up with one.

Neither of those pumps are macerators. One is a water pump and the other a bilge pump.

[Bobert]

sThanks for the info, Hans.
Att. is a pic of the pump/macerator? next to the head and before the tank.
Am I to understand that using the head to fill the holding tank that when the tank gets filled it will then begin pumping overboard? Have I got that right?

[tomschauer]

Ok, you need to dig into this.
First of all, it is illegal to discharge black water within three miles of the coast.
Your system should in no way "automatically" empty the tank. If someone set it up like that you will really P off your dock mates and end up with a couple $k in fines.
Trace your lines. If your line goes directley from the toilet to the tank with no Y valve, you don't have the ability to directly discharge. This is a good thing. it looks like you have a pump that is capable to empty your tank through the thru hull you described earlier. Follow the line from the bottom of the tank. It should go to a Y valve somewhere before that pump and before your deck pump out fitting.
You should also have a breaker marked waste pump, and usually a switch near that pump so you cannot accidently pump overboard. If you never go more than three miles off the coast that pump should be disabled. When within two miles of the coast it needs to be turned off, the Y valve locked to the deck fitting position and the thru hull closed to prevent a warning or fine from the coast guard.

[Midnightsun]

Need a picture of the holding tank and lines entering it to figure out what you have. If there are 2 white 1 1/2" line attached to your tank you will have a Y valve somewhere. If there are 3, most likely just hit the macerator switch to pump the tank overboard at will with no valves to fiddle with. As mentioned earlier, Y valves are frequently not installed depending on the manufacturer's choice at time of build.

Have seen Y valves on earlier build however on newer build no Y valve from the same manufacturer.