What causes joker valve failure?

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Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
I've been testing a bunch of chemicals on a fleet of donated joker valves from Groco, Jabsco, and Raritan. We're measuring changes in stiffness, resilience and size. We have a test rig (flanges and a standpipe) where we can test for leakage (back flow). We have installed all 3 types in test boats on matching heads (they are dimensionally interchangable) for field testing.

  • ethylene glycol
  • propylene glycol
  • methanol
  • CLR
  • vinegar
  • urine
  • ammonia
  • bleach
  • Aqua-Kem
  • Lysol Toilet Bowl Cleaner
  • baby oil
  • corn oil
  • olive oil
  • water proof grease
Surprisingly, even after months of exposure we have seen no dramatic failures. While there are a few that caused negative changes, even after months of exposure, only one chemical on the list cause leakage, and only on one valve--stale urine. Strikingly, it was a valve with a strong reputation for durability. I'm quite certain that we left it in stronger stale pee FAR longer than anything in the real world, I hope (I don't want to see the boat that is like that).


I've certainly seen joker valves begin to leak. Sometimes they simply have something lodged that some vigorous pumping will clear. Sometimes after years of use there is just enough scale on the lips to preclude a tight seal. If enough water was flushed to clear the line, backflow is not very serious anyway.


Has anyone experienced a failure due to chemical that included blistering or gross distortion? Any thought why one would be more durable or trouble-free than the others?
 

Rick D

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Jun 14, 2008
7,131
Hunter Legend 40.5 Shoreline Marina Long Beach CA
In my experience, the Joker isn't a problem until it gets calcified. I suspect that is because we use a minimum flush water for holding tank capacity and I had mistakenly thought using a shot of CP before leaving and then a good flush would take care of it. Then Peggy told me CP isn't for calcium control and I should do the vinegar thing before leaving also. I have been doing that for a year. However, I didn't get a build up until a year before, so I can't tell what difference it makes. there is a low spot at the joker on my boat, so that is where it would accumulate. BTW, we use the boat maybe 25% of the time, so the head gets a good work out. Also, I used to change out the pump yearly, so I naturally changed the joker valve then too. I am currently going on my third on this Jabsco pump. PH ll next time.
 
Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
In my experience, the Joker isn't a problem until it gets calcified. I suspect that is because we use a minimum flush water for holding tank capacity and I had mistakenly thought using a shot of CP before leaving and then a good flush would take care of it. Then Peggy told me CP isn't for calcium control and I should do the vinegar thing before leaving also. I have been doing that for a year. However, I didn't get a build up until a year before, so I can't tell what difference it makes. there is a low spot at the joker on my boat, so that is where it would accumulate. BTW, we use the boat maybe 25% of the time, so the head gets a good work out. Also, I used to change out the pump yearly, so I naturally changed the joker valve then too. I am currently going on my third on this Jabsco pump. PH ll next time.
What goes wrong with the pump? Even with that use, a year seems pretty short. There are live-boards that go many years.

I have a theory that in someways live-aboards are easier on scale; the scale forming reaction is not instant, it really seems to take a few days, and so those of us that come and go are in some ways a more severe test.

Perhaps the most important thing is to give a good long flush before leaving; it requires stale urine to scale, and stale urine can scale even with a fresh water flush (assuming the flush is not enough).
 
May 10, 2008
392
Catalina 355 Boston
Can't help with your question, but I'm curious as to whether you are testing with both sea water flushing and fresh water flushing regiments? Would be interested to see if that plays any kind of role....
 
Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
Can't help with your question, but I'm curious as to whether you are testing with both sea water flushing and fresh water flushing regiments? Would be interested to see if that plays any kind of role....
Good question. Depends.

We soaked valves in either fresh or seawater first to estabilish a baseline (no changes). In many cases salt makes little sense (winterization chemicals or chemicals that would likely be pre-dilutued with tap water).

  • ethylene glycol. 70% fresh.
  • propylene glycol. 70% fresh.
  • methanol. fresh, as out of the windshield AF bottle.
  • CLR. fresh according to directions.
  • vinegar. fresh 50%.
  • urine. no dilution, 50% with salt, 50% with fresh.
  • ammonia. fresh 70%.
  • bleach. fresh 70%.
  • Aqua-Kem. fresh and salt 80%. No difference.
  • Lysol Toilet Bowl Cleaner. fresh 80%.
  • baby oil. fresh 95%.
  • corn oil. fresh 95%.
  • olive oil. fresh 95%.
  • water proof grease. fresh with just a coating of grease on the inside.
Curiously, the amount of scale with the urine depended far more on the amount of urine than the water type; the undiluted urine scaled most, though the saltwater deposits seemed a little harder. The amount of scale does not depend much on the surface (glass, valve any brand, PVC).
 
Last edited:

weinie

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Sep 6, 2010
1,297
Jeanneau 349 port washington, ny
Are the samples left completely submerged in the solution during the entire test?
Oxidation obviously requires exposure to the air. Plus, i would think that a valve that is exposed to a liquid which then proceeds to evaporate, leaving behind dissolved solids, would be a more realistic scenario.
 
Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
Are the samples left completely submerged in the solution during the entire test?
Oxidation obviously requires exposure to the air. Plus, i would think that a valve that is exposed to a liquid which then proceeds to evaporate, leaving behind dissolved solids, would be a more realistic scenario.
I'm not certain I understand how the joker valve is going to see much air. It will be water sealed on both sides, no? Some air, as in the bottles, but not fresh air and evaporation I think. I also remove the samples weekly, evaluated changes, and placed them back in the jars in a different order. Since the top valve was intentionally partially exposed to air, there was some exposure.

"Realistic" is often a moving target. Every boat is used differently, water varies and maintenance varies. The best we can do is pick a few "normal" scenarios and then control as many variables as possible. Then we add field testing, expereince, and ask questions.
 
Apr 2, 2011
185
Catalina 27 Niceville, FL
I think joker valves often catch the blame for other problems. I have had the same one doing great for 10 years. Still, they do go bad. I DO know that bleach will destroy the bottom pump valve on a Groco HF. Replaced several until I figured that out.
 
Apr 1, 2004
145
Catalina 34 Herring Bay Chesapeake, MD
When I flush my head I pump 5 times in WET mode, then 10 times in dry. (minimum # of pumps)
I assume that during the majority of pumps in dry mode air is passing thru and around the joker valve.
Additionally the reason I pump at least 10 times in dry mode is to insure that all contents are pumped into the holding tank. Ideally the discharge hose from the head will then be empty which should help alleviate hose permutation. If I have no fluids in the discharge hose and my vent is open to the holding tank then air can reach my joker valve.

I change my JV yearly, Donnybrook must have one hell of a JV to have that rubber remain pliable/flexible for 10 years.

ThinWater, keep testing..................


Steve_C
 
Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
When I flush my head I pump 5 times in WET mode, then 10 times in dry. (minimum # of pumps)
I assume that during the majority of pumps in dry mode air is passing thru and around the joker valve.
Additionally the reason I pump at least 10 times in dry mode is to insure that all contents are pumped into the holding tank. Ideally the discharge hose from the head will then be empty which should help alleviate hose permutation. If I have no fluids in the discharge hose and my vent is open to the holding tank then air can reach my joker valve.

I change my JV yearly, Donnybrook must have one hell of a JV to have that rubber remain pliable/flexible for 10 years.

ThinWater, keep testing..................


Steve_C
The thing is that pumping in dry mode does not dry the hose. Yes, it pushes most of the water through and is good practice, but it's not hard to imagine that some of the water flows down one side while air goes up the other. I've never opened a pump where there was not enough water (a few ounces) to keep the valve under water. Even the air that is there will soon go stale and there will be no evaporation (the air in the holding tank is certainly at saturation).

But the thing of it is this; any sailor who flushes as you do is not going to see any sort of soaking chemical exposure! Good! The only way there is going to be chemical damage is if the user leaves the chemicals in the pump with little flushing, hence the wet testing. It seems some leave the chemicals to soak when they leave the boat.
 
Dec 2, 2003
1,637
Hunter 376 Warsash, England --
Joker Valve NON Failure

For what its worth my boat is nearly 17 years old, has a Jabsco toilet and I have never seen my joker valve.
It has not given a moment's trouble either.
The boat is used for normal weekending and extended summer cruises.
The secret is that the diverter valve for overboard versus holding tank has NEVER been in the holding tank position. This allows us to pump plenty of water to flush the pan AND the outlet pipe. I calculated it needed at least 20 pump strokes to get everything away.

You may be horrified but, using best scientific principles, the pundits calculated that toilet discharges from yachts would never be sufficient to have any measurable or significant effect on the environment - and this is in the Solent which has the most dense population of leisure craft anywhere.

But, since everyone got so particular about the environment we have exclusively used marina and other shoreside facilities for the full works toilet functions but continue to use the Jabsco for the occasional pee whilst under way or in the middle of the night.
Result - no failures of joker valves - just like the rubber technologists intended.
Also I have this notice taped to the bulkhead in the loo. The secret is the 20 pulls of the pump AFTER whatever is there has been pumped out of sight in the pan.


THREE STEPS TO POTTY TRAINING
LEVER TO LEFT & PUMP SOME WATER INTO THE PAN
LEVER TO RIGHT AND PUMP ‘IT’ OUT OF THE BOWL
LEVER TO LEFT AND 20 PULLS TO FLUSH ‘IT’ OUT OF SYSTEM
That's all you need to do.

PLEASE LEAVE LEVER TO the LEFT

IF 'DRY BOWL' IS NEEDED LEVER RIGHT AND PUMP UNTIL DRY
 

Rick D

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Jun 14, 2008
7,131
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Some Answers: re Pump Replacement Interval

What goes wrong with the pump? Even with that use, a year seems pretty short. There are live-boards that go many years. I agree. The first generation pumps were fine. I would overhaul them ever couple of years. The second generation pumps were, IMHO, not rebuildable. The studs would fracture and then it would leak. It was cheaper and more effective to replace the assembly. I had flapper valve failures when the weight delaminated from the rubber, the shaft piston nut failed, the dry/wet valve failed multiple times, one pump kept seizing, I think the cylinder wasn't true, the base cracked and was replaced. That's just what I remember. The third generation pump seems to be holding up well.

I have a theory that in someways live-aboards are easier on scale; the scale forming reaction is not instant, it really seems to take a few days, and so those of us that come and go are in some ways a more severe test. I think that may well be correct. We use our boat frequently, days to months at a time with days to a couple of weeks break. I also have had continuous problems with the Seaward water heaters. I do not leave them on when I leave. I am on my third in 15 years and I think it too may be going out. I suspect the expansion/contraction cycles has something to do with it. There are lots of live-aboards that never have problems, maybe because they are left on full time?

Perhaps the most important thing is to give a good long flush before leaving; it requires stale urine to scale, and stale urine can scale even with a fresh water flush (assuming the flush is not enough). Well, I have always done just that. Maybe the vinegar will make a difference. I don't intend to crack the housing prematurely to find out, however.
See comments embedded.
 
Jan 1, 2006
7,039
Slickcraft 26 Sailfish
I barely get a year out of mine. We only use fresh water to pump. We pump a gallon through after the bowl is empty.
There is no doubt when it fails - the back flow on port tack is intolerable.
 
Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
I barely get a year out of mine. We only use fresh water to pump. We pump a gallon through after the bowl is empty.
There is no doubt when it fails - the back flow on port tack is intolerable.
If boat builders KNOW that joker valves fail and allow flowback, why don't they put a priority on smarter hose routing? I guess that's not what sells boats.
 
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