Questions on Vacuum Toilets

[FlushedAway]

I'm designing a vacuum toilet system for a commercial trailer bathroom and need some information...

1. Does the vacuum system allow for the occasional plastic tampon or other small foreign object in the system?

2. How long does it take for a vacuum system to build vacuum?

3. What makes a vacuum toilet different from a rv toilet?

4. How long do the diaphragm pumps last?


below is the system I've designed

 

[Stu Jackson]

Seems to me that you'd find an answer from the websites of the vendors who make vacuum heads.

 

[Steve Dion]

Why don't you just buy one from SeaLand for about $500? If/when you need parts there will be a place to buy them.

 

[petersea]

Your diagram is not a true vacuum type system and as there is not a vacuum tank. All you are doing is using a pump to suck out the bowl contents. You proposed plan uses the pump as a liquid pump not a vacuum . Vacuum pump are designed to supply the pressure so that a pre loaded vacuum suction force empty's the bowl contents. Typical RV heads are thru and thru in that they will not hold pressure in the line whereas a true vacuum type head has a ball value that will hold pressure behind it in the system. No where in you plan do I see a water supply to the system ?? You need to review some of the systems in use already to get a better understanding of what a vacuum pump system is. Your design will work until the bowl has gone dry and sucks air instead of liquid. At that point unless there is a positive gravity pull the volume of the bowl contents will most likely stop flowing. AND no system should every have a plastic or paper tampon or similar object flushed thru the system unless you want to take it apart to clear the clog !

p.s. you may want to purchase Peggy Hall's book on sanitation systems available here on this sites store

 

[Rick]

Concure with Peter completely. I have a Vacuflush system and love it. You just have to live by its rules. The way it works is described by Peter perfectly. Your design will not work in its existing form

OR you could just simply buy one of these. Simple and its plug and play. My guess is by the time you buy the individual parts and go through the headaches of assembly.. this would be a better solution.

Good luck and its a great system. You can flush a "loaf of bread" down it, but nothing else except for body functions and marine grade TP.

http://dometicsanitation.com/International/PG-6985-VacuFlush-Toilet-Systems/PG-6989-Holding-Tanks

 

[FlushedAway]

The diagram only shows the vacuum side...

The tank is the pipe that the vacuum sensor is connected too, the pipe can be a different diameter or length.

The RV toilet we have has a gasket which seems to work better when vacuum is applied to it, it's a gasket on the top of the ball, when vacuum is applied it looks like it presses into the ball more.... that's the theory anyway.

We did more research into the the fact that these systems still are too picky about what you put in them thus we are going to use a porta-potty flushing toilet instead since it's dirt cheap. The bowl and the tank are combined so it saves space and is gravity fed. Also you can put anything in them and it'll still keep working... pumping it out after, that's another story.

There are 2 ways to prevent bad objects from passing through the pump, one is to make the holding tank vacuum, or to vacuum the pipe there needs to be a way to prevent the holding tank air from entering in the system but there's way's to fix that.

 

[Dave Howard]

Eco Vac System

I'm a new sailboat owner and my Hunter 42 has this system in both heads. Problem is one of the heads flushes fine but the pump keeps running so there must be an air leak somewhere in the system.
How do you find the leak?

 

[Peggie Hall HeadMistress]

I have to ask: WHY a vacuum system? And why "reinvent the wheel" if you do insist on a vacuum system? Mansfield Plumbing invented the VacuFlush toilet in 1978...they spun off their entire marine toilet division to a startup called SeaLand Technology (now owned by a European company called Dometic) in 1984 ...and although vacuum toilet technology was surpassed by macerating electric toilets in the early '90s, the VacuFlush is still sold and is a popular among many boat owners. So why NOT just go with it? Or better yet, with a macerating electric toilet, some of which have a pump powerful enough to move bowl contents as far as they need to go to reach the holding tank and can even chew up the occasional tampon...something no vacuum system can do?

If you'd like to email me, I'll be glad help you design a system using already available equipment that should be what you need.

Dave...If you'd like to email me (EMAIL, not PM!), I'll send you the Vacuflush trouble shooting guide that should help you find the air leak or other reason your pump keeps cycling.