Upward bend in sanitary line

[john6206]

Hi everyone,

It seems like the logical design would be a downward slope from the head to the holding tank. When I replaced my lines on my Catalina 320 there was an upward bend from the toilet to a 180° turn that leads to the tank. This looks like the only way the hose can get where it’s going.

Is this normal?

Doesn’t that mean there will always be about a half a gallon of water in that loop?

And when I say “water” …

 

[dlochner]

Ideally gravity would do all the work like it does in your house. The realities of a boat are that sometimes "water" has to go up hill. The pumps on marine toilets can pump fluid uphill so this is not a problem, but does require you to keep pumping after the bowl is dry to get the fluid over the high spot so gravity can take over.

To make this work the pump must be in good working order and properly maintained. The other very important part is the joker valve. This valve prevents fluid from flowing back into the toilet between pumps. Once it starts to wear, it is more difficult to impossible to maintain enough pressure for the pump work efficiently. For many of us it is an annual maintenance item.

For everything you ever wanted to know and then some about get Marine Sanitation get Peggy Hall's book.

 

[Calif. Ted]

Is this normal?

Yes, a couple pumps in the "dry" position clears hose contents into the tank. It's a "piston" pump, a type of positive displacement pump that works with air or liquid.

 

[Ralph Johnstone]

It's a "piston" pump, a type of positive displacement pump that works with air or liquid.

I there any reason why you can't just come out and tell us what the make and model of the pump is ? Top secret prototype maybe ?

 

[colemj]

Is your holding tank above the level of the toilet discharge? Do you have the option to discharge overboard?

If either of these are true, then the discharge hose has to rise above either the holding tank or the waterline before heading back down.

The other consideration is the practical one that the hose usually has to be routed somewhere out of sight, where going uphill a bit to get a clear shot down to the tank/thruhull is necessary.

Mark

 

[Calif. Ted]

I there any reason why you can't just come out and tell us what the make and model of the pump is ? Top secret prototype maybe ?

I was thinking of a manual head, Jabsco or Raritan, if the handle goes up and down or in and out it's a piston pump.

 

[john6206]

@Ralph Johnstone
he can’t tell you because he’s not the op….but I can tell you.
it’s a Jabsco manual toilet (with a piston pump!)

i wonder if either the toilet isn’t working properly or if I’m using it wrong, because when I removed the hose … huge mess - smelled the a bad neighborhood in Hell.

I‘ll admit I’m paranoid about my small holding tank (with no tank monitor), but I do follow both Peggy’s advice, and the advice of multiple strangers on YouTube. “use enough water to clean the bowl and then switch to dry mode and pump a bunch of times” I usually go like 10 pumps in dry mode.

Who knows? Hopefully the new Sani-flex takes care of the head funk, now I can focus and “where is that water in the bilge coming from?????”

 

[jssailem]

Your pump can push effluent about 3.5feet vertically up and over the top of the loop. From there gravity should carry the effluent down to the holding tank. The hose should run at about a 4 degree down angle. Enough to give gravity a direction, but not to steep that all the liquid flows away leaving solids behind.

That is my understanding.