Winterizing the Head Holding Tank

Dec 2, 1997
8,124
- - LIttle Rock
Peggy, I know how pumps work. My grandfather was an engineer, my father was an engineer, I'm an engineer, two of my kids are engineers (one Ph.D., my daughter is an architect). Technology runs in the family.

I still don't buy it. I can see "inspect," or test, if there is an objective test of joker valve performance. But annual replacement is just over the top, in my opinion. Unnecessary, wasteful of time and money. Also, you're putting wear on those plastic threads cut by the screws in the pump housing. (Not really an issue, but I just thought I'd throw that in.). If you said five years, yea, O.K., I can buy that. But I guess it depends more on use than time, and what you might be forcing through it, and how salty your flush water might be, and so on, and so on. Or, if you said 'take it out and clean it, in vinegar, if necessary, lubricate it, and replace it,' I could buy that, too. But just taking out and tossing a one year old joker valve, regardless of use, condition, or performance, is just too much.
Apparently you think I just make this stuff up, but I'm actually just the messenger, sharing what I've learned--and still continue to learn--from engineers at equipment manufacturers and other qualified sources. It was a toilet mfr who taught me the reason why joker valves in manual toilets should be replaced at least annually and I'm sure the engineers at any of the toilet mfrs would be glad to explain the value of PREVENTIVE maintenance vs. "only fix what breaks" to you.

And I'm definitely be interested in learning from them what lubricating a joker valve accomplishes or how cleaning one in anything, especially vinegar, can cause a stretched slit to close up tight again. I was taught that when soft rubber (joker valve) is allowed to sit and soak in vinegar it swells up and distorts...the reason why vinegar should never be left to sit in the bowl.

Please do report back after your conversation with one of them...I'm always open to learning something new.

--Peggie
 

jviss

.
Feb 5, 2004
4,627
Tartan 3800 Westport, MA
Apparently you think I just make this stuff up, but I'm actually just the messenger, sharing what I've learned--and still continue to learn--from engineers at equipment manufacturers and other qualified sources. It was a toilet mfr who taught me the reason why joker valves in manual toilets should be replaced at least annually and I'm sure the engineers at any of the toilet mfrs would be glad to explain the value of PREVENTIVE maintenance vs. "only fix what breaks" to you.

And I'm definitely be interested in learning from them what lubricating a joker valve accomplishes or how cleaning one in anything, especially vinegar, can cause a stretched slit to close up tight again. I was taught that when soft rubber (joker valve) is allowed to sit and soak in vinegar it swells up and distorts...the reason why vinegar should never be left to sit in the bowl.

Please do report back after your conversation with one of them...I'm always open to learning something new.

--Peggie
Please, Peggy, don't get into a twist over this. I do, indeed, respect your knowledge and experience, and if time and money were no object I would replace the joker valve at least annually.

I did some research on this a while ago. Practical Sailor did an excellent technical review of joker valves, here:
Joker Valves for Marine Heads

They are not all the same, even materials-wise.

Lubricating a joker valve? I think I got that from you! Maybe not, but I remember your trademark verb "slather."
 
Oct 26, 2008
5,015
Catalina 320 Barnegat, NJ
Um, I'd suggest that the manufacturers and the engineers whom support them would be on the over-conservative side if not for any other reason than they are most concerned with negative feedback from their consumers. Who would want to recommend that a joker valve will last more than a season when they encounter some users that have multiple, daily flushes with salt water. I'd suggest that YMMV and most of ours does. Many of us have very light duty on our flushing toilets. I can't see replacing a joker valve every season if the annual number of flushes may never even exceed 50 to 100, which may not be too far off for some of us. And sea water minerals may not even enter into the discussion in many of our boats.
 

jviss

.
Feb 5, 2004
4,627
Tartan 3800 Westport, MA
One thing I'd like to add, regarding this type of valve, is that they can dribble if there's insufficient back pressure. As a matter of fact, one that looks like it's no good when held in the hand, i.e., with a slight gap in the slit, can actually be fine with back pressure on it. Some head manufacturers recommend a minimum height for the discharge loop to keep enough water pressure against the joker to keep it closed.
 

jviss

.
Feb 5, 2004
4,627
Tartan 3800 Westport, MA
I'm definitely be interested in learning from them what lubricating a joker valve accomplishes
That's a good question! It might just be habit, but I always lubricate rubber parts when I put things together, like engines, marine heads, SCUBA regulators, etc. Don't know if it helps, or is necessary, but it couldn't hurt. :)

Things seem to seal better when they are lubricated.

Also, I'm not a fan of "slathering." A very thin film of lube is usually all that's required, anything more is either wasteful or even harmful, i.e., it collects dirt.