Advice for Waste System Design

[sndog]

I have designed my waste system, and before I plumb everything, I would love feedback on the system to ensure it is done correctly. I have two Raritan Marine Elegance Heads, A Raritan ElectroScan, and a 20G black water tank. This system is just for the two toilets.

Toilets are being ordered this week, the gulper, ElectroScan, and holding tank are already on board. If there is a recommendation for Y valves, please let me know. Runs from the heads to the tank area will be PVC pipe. The PVC will go directly to the heads. The PVC will be connected to the tanks via Saniflex hose. Connections from Y-valves to ElectroScan and waste tank and outputs from those to the thru-hull, will also be Saniflex.

The run from one head to the tank area is about 14ft, the other is about 40ft. The shorter run head will be about 18" above the top of the waste tank, and the head with the longer run will be about 18" below the top of the holding tank.

The DC-DC buck converters are being used due to the wire run length, and my central house bank sitting at 48VDC. There are spare DC-DC buck converters on board.

And always, thank you in advance.

 

[Cigatoo]

** if not too late Iwould want more than a 20 gallon holding tank. We have a 40 gallon tank and it fills up more quickly than I would like. That’s with just me and my wife on board. In retrospect, I would have the largest tank possible. Obviously without compromising space requirements for other systems.
**I would use PVC wherever possible. It sounds like you’re already doing that.
**Neither of our heads are-even connected to thru hull anymore. Where we are located it’s almost never possible to pump any waste overboard with good conscience

 

[SIBERNUT]

Is the head you are using able to pump uphill 18 " ? How about a check valve ?
That could get icky........

 

[sndog]

** if not too late Iwould want more than a 20 gallon holding tank. We have a 40 gallon tank and it fills up more quickly than I would like. That’s with just me and my wife on board. In retrospect, I would have the largest tank possible. Obviously without compromising space requirements for other systems.
**I would use PVC wherever possible. It sounds like you’re already doing that.
**Neither of our heads are-even connected to thru hull anymore. Where we are located it’s almost never possible to pump any waste overboard with good conscience

I do wish I could have a bigger one, and in the future, I may. Most of my space I have for tanks is being used for Water.

 

[sndog]

Is the head you are using able to pump uphill 18 " ? How about a check valve ?
That could get icky........

According to Raritan, it gives me a maximum vented loop height of 10'. I was planing to have the output of the toilet go up maybe 45 deg to the about 34" then start a slope down the rest of the way to the tank.

 

[Comodave]

The ME head is amazing and will pump up that high easily. BUT that is a really long discharge hose, pipe, to pump clean. It will take a lot of water to flush the poop all the way into the tank. The ME can use either 1” or 1.5” discharge hose. I use 1” because it takes less water to flush the hose clean after use. I have a 36’ discharge hose. With 1” the hose will hold 1.5 gallons of water. With a 1.5” hose it will hold more than twice as much water. I agree that 20 gallons is very small size. I would look for a different location for the tank or split the tank into 2 tanks, 1 for each head. That way you won’t have a long discharge hose to flush out each time. You don’t want to leave poop in the hose as it can dry out and make a solid blockage in the hose. We do a large flush after pooping and a short flush after peeing.