Life of a duckbill

H

happyhour

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exMember
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The duckbills in my vacuflush are less than a year old and have had little use. They are now mis-shappened just enough that they will not close. Is this a normal life span ?
Also I am getting the occasional clog. Inside various system components the uric acid has crystallized and provides a great spot for TP to catch. Is there any product I can put in the system to dissolve the build up ?
 
I am 2 years on my duckbills. I have a clogging problem but it is not the Vacu Flushe's problem there is an entire thread on it. You might want to try running vinagar through it and also they recommend soap for the seals. I run some dish detergent through it once in awhile. It sounds like your not running enough fresh water through it after the flush? I tend to hold my pedal down for about 10 seconds before I leave the boat to flush hopefully everything clean. Bill
 
It is a good idea to do a "clean water" flush for long enough to completely clear out the hoses between the bowl and the H/T every time you leave the boat ( ... for longer than a day or so ). This will reduce the chance of permeation as well as reduce buildup of crud of most types. This is true for all types of MSD. ( IMHO )
 
Ditto on what Bill & Bill said
I’m at 3 years with the Duck bills on my heads and no sign on any issues and my systems get used a lot
What kind of head treatment do you use?
I have been using K.O. & C.P. exclusively and I think they are better for the health of the components
 
how often does your pump cycle?

i've had duckbills lasting 6 or 7 years and still working well. they always look a little distorded anyway. one thing you cna do is put some soap on the flange when you put them in so that they dont' twist when you screw the fittings.

how about these? 7 or 8 years old and still working fine, they were on the intake side... only reason i opened it was that someone flushed a tampon. I thought long and hard about it and replaced them since the pump was open :-)

badduck.jpg
 
I have had the duck bill valves in my Vacu Flush for 8 years and have not had any problems. We are in the North East so the boat is not used for 6 months. I do keep a spare set on hand just in case I need to replace them.
 
Duckbill valves (also called joker valves) are also used in other heads besides the VacuFlush, and don't generally last that long in the other applications. As a rule of thumb, particularly in manual heads where they do double-duty, it's best to replace them every other year.

-- And be careful what types of additives and deodorants you use in the head. If you use the wrong things, the duckbills may have to be replaced as often as every few months. Follow the manufacturer's instructions in the Owner's Manual for your particular head. Keep in mind that marine toilets are different than household toilets, and you can't use the same chemicals and smell-good stuff in them, that you use at home.
 
I have seen duckbills last for 12 years, i have seen them last for 1 season. It all depends on how much you use them. I would avoid flushing any chemicals down the toilet other than some anti bacterial soap. This helps lubricate the parts inside the bowl and the pump, as well as keeping the system clean.
 
A tip from another RO was to use baby oil to keep the seal at the base of the bowl lubricated.

My duckbills are at least 7 years old.

The question is: What EXACTLY do they do? How do you knowwhen they are going bad?

RWS
 
Duckbills are molded rubber check valves (one way valves). VacuFlush uses 4 in their vacuum pumps - 2 on the intake side and 2 on the discharge side. The pairs are mounted in series; one backs up the other, to make them last longer and reduce the frequency of the vacuum pump coming on between flushes. Their purpose is to maintain the vacuum in the vacuum tank and the line between the toilet pedestal and the vacuum pump.

In other marine toilets, they serve as check valves to direct the flow out of the toilet, or to stop backflow from returning into the toilet bowl.
 
I'm on 3 years on my heads and my sealand waste pump, they may be working fine but they are all on the spring ta do list this season.
 
I have a Raritan toilet (I think) with a Lectra-San hooked up to it. Have 14 seasons on unit & can only recall replacing joker valve once in all that time. Not really sure why it was replaced at the time. Believe I was replacing macerator pump & thought it w/b good time to do so.
 
P.was she buried at sea or dragged back to land?
 
Don't know what a duckbill really is or where it is. I have an electric head not vacuflush. Do I have ducks?
 
"Don't know what a duckbill really is or where it is." -- TurboWarp

See Vic's explanation, above. It is a good one.

"I have an electric head not vacuflush. Do I have ducks?" -- TurboWarp

To the best of my knowledge, -all- marine heads have "duckbills" aka: joker valve, aka: check valve.

Some non-marine sanitation systems us a "direct drop" method, and do not require them. But it is very unlikely that you would see such a system on a boat. ie: You got 'em.

Here is a link to the Sea Era expladed parts diagram. Part "C254" is the joker valve.
 
C254 looks diffrent from what Pascal showed. About how big are duckbills?
 
Uh, Turbo, just like women's "torso mounted attention getters", they come in all sizes and somewhat different designs, but all serve the same function.

Give us the make/model of your marine head, and I ( we ) will attempt to get the exploded diagram for -your- marine head.

But they all work on one of a limited number of principals ( vacu-flush and all others ), and all have similar pieces/parts. The "flapper/joker/check/duckbill" valve, in virtually all systems, can be found on the exit side of the toilet, and is used to keep effluent traveling away from the toilet and into the holding tank.
 
Bill said, "Uh, Turbo, just like women's "torso mounted attention getters", they come in all sizes and somewhat different designs, but all serve the same function."

Good description for both...! The joker valve shown on the SeaEra exploded parts view is a criss-cross configuration whereas most joker valves have a single slit in them, see part # C253 in the following (in the center of the drawing):

http://www.raritaneng.com/pdf_files/crown_head_II/L345crownheadIIv0702.pdf

That's the more traditional configuration for a duckbill valve. You'll see why they are also called duckbill valves - they look somewhat like a duck's bill. But yes, they come in different shapes and sizes, depending upon their particular application.

The way they work is that reverse pressure coming against the duckbill portion of the valve causes it to seal, stopping any flow from going the other way. The force of the flow opens them when the toilet or pump is operating. Then when it stops, any reverse pressure pressure causes them to seal off.

The duckbills that Pascal showed on his post had been used for quite a few years, and had a pretty good buildup on them - they certainly didn't look like that when they were new. As they age, they acquire a buildup of sewage, minerals from the water, etc., etc., and deform - and no longer seal like they did when they were new. That's when they need to be replaced.
 
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