Head plumbing

[LeoA]

I am in the process of redoing the tanks on my boat and my question is how far can the holding tank be from the manual pump head and work well? I will be able to use 1 1/2 pic pipe for the majority of the run. Is 15 feet of pipe too much between the head and tank?

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[steve77]

There should be no issues with pressure loss, so I'm going to assume you are only concerned about the volume of the hose.

Even the best hose can seep odors if nasty stuff is left in there for long periods. I believe you will find most people will advise you to pump the head enough to get all the nasty stuff out of the hose and to the holding tank.

I did a quick calc and come up with a volume of 1.4 gallons for a 1-1/2" diameter pipe that is 15 feet long.

Just consider that volume and how quickly your holding tank will fill up, and you can make an informed decision on how long the hose can be.

Cheers!

Steve

[peghall]

15' without any help from gravity is way too far. 6' is the optimal distance because that's as far as a manual toilet can move bowl contents in the amount time most people will spend pumping it. However, the distance can be extended if you can plumb the system to create some help from gravity. That can be accomplished by installing a loop--not necessarily vented--in the discharge line that's immediately after the toilet. You'll only have to pump enough times to push the bowl contents over the top the loop. This helps to conserve flush water too...even more if you learn how to use the dry mode to do more than just push the last of the water out of the bowl.

Few people realize that air pressure created by pumping a manual toilet that's working anywhere close to factory specs can move bowl through the system up to about 6 linear feet or 4 vertical feet in the dry mode. So use the dry mode to push the flush over the top of the loop! Switch back to the “wet mode” for a couple of pumps to bring in water to rinse the pump and discharge line, then switch back to dry to pump that through to the tank. Cuts flush water consumption by at least 50%, which can double the number flushes a tank can hold...AND keeps the discharge hose rinsed out.

[LeoA]

Thank you, Peghall, that is the information that I needed.

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