I own a 2005 Benetaeu 331 and for some unknown reason - unknown to me at least, the head keeps filling up with water. I'll eject waste into the holding tank, and within minutes water has backfilled into the head. Does anyone know what the problem is, and how I fix it. This is a real "Head"-ache. Jake
Head backfill
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If it really IS backflow, check the tank vent.
When the tank vent becomes blocked, the tank becomes pressurized, creating backpressure that causes waste to back up into the toilet. It can get worse...a burst tank, or if you're lucky, only an eruption in the toilet. However, if the water is clean, it's not backflow, it's seaa water. The source can only be the flush water intake. Which can only mean that a) the wet/dry valve in the toilet has failed, and b) there's no vented loop im the toilet intake.
When the tank vent becomes blocked, the tank becomes pressurized, creating backpressure that causes waste to back up into the toilet. It can get worse...a burst tank, or if you're lucky, only an eruption in the toilet. However, if the water is clean, it's not backflow, it's seaa water. The source can only be the flush water intake. Which can only mean that a) the wet/dry valve in the toilet has failed, and b) there's no vented loop im the toilet intake.
Joker valve
If it was working properly prior to this then try replacing the joker valve. Beneteau uses Jabsco heads and the joker valves in them are prone to the problem your experiencing. Most likely a build up or calcification on the edges of the valve which prevents it from closing fully. Flush plenty of fresh water though first so any back flow will be minimally nasty when you crack open the connection for the joker valve. Note that anything sitting in the toilet to holding tank will come out when you remove the joker valve. Lot's of paper towels are in order. Don't forget to close down your intake thru hull first.
If it was working properly prior to this then try replacing the joker valve. Beneteau uses Jabsco heads and the joker valves in them are prone to the problem your experiencing. Most likely a build up or calcification on the edges of the valve which prevents it from closing fully. Flush plenty of fresh water though first so any back flow will be minimally nasty when you crack open the connection for the joker valve. Note that anything sitting in the toilet to holding tank will come out when you remove the joker valve. Lot's of paper towels are in order. Don't forget to close down your intake thru hull first.
A failing joker valve can cause some seepage, but.
But the bowl wouldn't refill unless a) the head discharge line runs uphill all the way to the tank and b) it's full of waste because the toilet wasn't pumped enough times to push it into the tank. So since too many people stop pumping as soon as the bowl is empty, leaving the bowl contents to sit in the line, that is a possibility. But before removing the head discharge fittingto check the condition of the joker valve--or any other hose connection in the system, including the vent line, I'd strongly recommend opening the deck pumpout fitting to relieve any pressure in the system. And I'd make sure to be downwind of the fitting, and have a hose at the ready, when you do it.
But the bowl wouldn't refill unless a) the head discharge line runs uphill all the way to the tank and b) it's full of waste because the toilet wasn't pumped enough times to push it into the tank. So since too many people stop pumping as soon as the bowl is empty, leaving the bowl contents to sit in the line, that is a possibility. But before removing the head discharge fittingto check the condition of the joker valve--or any other hose connection in the system, including the vent line, I'd strongly recommend opening the deck pumpout fitting to relieve any pressure in the system. And I'd make sure to be downwind of the fitting, and have a hose at the ready, when you do it.
Gotta pump it clean
Peggy that's exactly how my B361 is plumbed, the discharge hose runs straight up to the top of the holding tank. It's why I recommened he pump a lot of fresh water through the system before opening the connection to the joker valve. I've had the problem numerous times so I know it's a messy job unless you think ahead. Hard lessons learned
Mike
Peggy that's exactly how my B361 is plumbed, the discharge hose runs straight up to the top of the holding tank. It's why I recommened he pump a lot of fresh water through the system before opening the connection to the joker valve. I've had the problem numerous times so I know it's a messy job unless you think ahead. Hard lessons learned
MikeThe joker valve does NOT seal the discharge line
except during the actual upward pump stroke that pulls water/waste from the bowl into the pump. That is the reason for its shape - on the up-stroke, it 'sucks' itself together, forming a seal. Other than that, it is NOT intended to seal anything, and you can change/replace it all day long without affecting your problem. BTW, if you carefully wrap a large plastic trash bag (NOT a Walmart-type bag) around the base of the Jabsco toilet and secure it with a couple pieces of duct tape, ALL of the stuff in the toilet and discharge line will be neatly collected for disposal, rather than collecting in the bilge. The seepage is coming through the 'flapper valve' at the bottom of the pump. This valve rotates UP on the pump's up-stroke to draw water/waste in, then DOWN to direct the water/waste into the discharge line. When the pump is not in operation, it should be DOWN, which seals the bowl from the discharge line. If your seepage is not sea-water, then the only other possibility is that water is getting past this flapper valve. If the flapper valve is not sealing correctly, you will sometimes see water and/or air coming back into the bottom of the bowl on the pump down-stroke. This could be caused by deformity of the valve or it might be blocked by waste, or crud might have built up on it. I have found that this valve will inevitably start leaking. What to do? First, if the valve is not seating/sealing properly, you CANNOT get full pressure out of the pump, and it will be impossible to completely clear the discharge line, which means that water/waste will ALWAYS be there and it will ALWAYS seep back through.... the improperly seated/sealed valve. So you can replace the valve, which will provide some entertainment (I know, I have a crappy sense of humor) and help for a little while.... but you probably recall my use of the term 'inevitable' above. Or, you could replace the Jabsco with a REAL toilet.... Peggy can recommend a good one. I keep my Jabsco because it fits my above-mentioned crappy sense of humor. Me? I flush enough to get 'clean' water in the discharge line, then use my shower nozzle to put enough fresh water in the bowl to counter-act the pressure of any water left in the discharge line. Takes about half a bowl-full, figure half a gallon. And I dream about my next boat, which will DEFINITELY have a Letra-San. ;D Cheers, BobW s/v X SAIL R 8
except during the actual upward pump stroke that pulls water/waste from the bowl into the pump. That is the reason for its shape - on the up-stroke, it 'sucks' itself together, forming a seal. Other than that, it is NOT intended to seal anything, and you can change/replace it all day long without affecting your problem. BTW, if you carefully wrap a large plastic trash bag (NOT a Walmart-type bag) around the base of the Jabsco toilet and secure it with a couple pieces of duct tape, ALL of the stuff in the toilet and discharge line will be neatly collected for disposal, rather than collecting in the bilge.
The seepage is coming through the 'flapper valve' at the bottom of the pump. This valve rotates UP on the pump's up-stroke to draw water/waste in, then DOWN to direct the water/waste into the discharge line. When the pump is not in operation, it should be DOWN, which seals the bowl from the discharge line. If your seepage is not sea-water, then the only other possibility is that water is getting past this flapper valve. If the flapper valve is not sealing correctly, you will sometimes see water and/or air coming back into the bottom of the bowl on the pump down-stroke. This could be caused by deformity of the valve or it might be blocked by waste, or crud might have built up on it. I have found that this valve will inevitably start leaking. What to do? First, if the valve is not seating/sealing properly, you CANNOT get full pressure out of the pump, and it will be impossible to completely clear the discharge line, which means that water/waste will ALWAYS be there and it will ALWAYS seep back through.... the improperly seated/sealed valve. So you can replace the valve, which will provide some entertainment (I know, I have a crappy sense of humor) and help for a little while.... but you probably recall my use of the term 'inevitable' above. Or, you could replace the Jabsco with a REAL toilet.... Peggy can recommend a good one. I keep my Jabsco because it fits my above-mentioned crappy sense of humor. Me? I flush enough to get 'clean' water in the discharge line, then use my shower nozzle to put enough fresh water in the bowl to counter-act the pressure of any water left in the discharge line. Takes about half a bowl-full, figure half a gallon. And I dream about my next boat, which will DEFINITELY have a Letra-San. ;D Cheers, BobW s/v X SAIL R 8Hate to disappoint you
Bob I hate to disappoint you but I've replaced the joker valve more than once for the problem. I can tell you from experince if the flaps on that valve begin to build up residue it will leak and allow water to slowly refill the bowl. I don't disagree there may be other sources of the problem but the joker valve in a Jabsco can do it and is probably the quickest and easiest fix before setting off to other problems. Mike
Bob I hate to disappoint you but I've replaced the joker valve more than once for the problem. I can tell you from experince if the flaps on that valve begin to build up residue it will leak and allow water to slowly refill the bowl. I don't disagree there may be other sources of the problem but the joker valve in a Jabsco can do it and is probably the quickest and easiest fix before setting off to other problems. Mike
A new Joker valve will make you think you got it..
but in fact, you haven't. A new Joker valve, before it gets any gunk on it, will indeed form a pretty good seal, but here's the operative question: Where does the water from the discharge hose GO, once it gets past the Joker valve? If you said: 'Into the tank', you'd be wrong. It goes to the 'flapper valve' or, more properly (because I looked it up!) the 'Base Valve Gasket', which is part # 16 in the parts diagram in the link below. THIS is the part that actually lets water seep back into the bowl, NOT the Joker valve. If you look at the parts diagram (or more importantly, if you disassemble the pump and look closely at its functionality) you'll see that nothing can get back into the bowl without going through this valve. In fact, you could completely REMOVE the Joker Valve without having ANY effect on the seepage - if the Base Valve Gasket is leaking, it will let water back into the bowl, and if it isn't, it won't. (Remember, the Joker Valve is there ONLY to seal the discharge hose during the pump up-stroke) The ironic thing is that the buildup of gunk on the Joker Valve isn't really a problem until it gets pretty bad. That's because of the design of that valve and how it 'sucks itself together' on the pump up-stroke.... that's what it's supposed to do. So you can replace Joker Valves all you want, but you're NOT addressing the real problem causing seepage back into the bowl. It's the Base Valve Gasket that SEALS the passage. Cheers, Bob s/v X SAIL R 8
but in fact, you haven't. A new Joker valve, before it gets any gunk on it, will indeed form a pretty good seal, but here's the operative question: Where does the water from the discharge hose GO, once it gets past the Joker valve? If you said: 'Into the tank', you'd be wrong. It goes to the 'flapper valve' or, more properly (because I looked it up!) the 'Base Valve Gasket', which is part # 16 in the parts diagram in the link below. THIS is the part that actually lets water seep back into the bowl, NOT the Joker valve. If you look at the parts diagram (or more importantly, if you disassemble the pump and look closely at its functionality) you'll see that nothing can get back into the bowl without going through this valve. In fact, you could completely REMOVE the Joker Valve without having ANY effect on the seepage - if the Base Valve Gasket is leaking, it will let water back into the bowl, and if it isn't, it won't. (Remember, the Joker Valve is there ONLY to seal the discharge hose during the pump up-stroke) The ironic thing is that the buildup of gunk on the Joker Valve isn't really a problem until it gets pretty bad. That's because of the design of that valve and how it 'sucks itself together' on the pump up-stroke.... that's what it's supposed to do. So you can replace Joker Valves all you want, but you're NOT addressing the real problem causing seepage back into the bowl. It's the Base Valve Gasket that SEALS the passage. Cheers, Bob s/v X SAIL R 8
Bob, I think you need to read some things again...
You said, "Where does the water from the discharge hose GO, once it gets past the Joker valve? If you said: 'Into the tank', you'd be wrong. It goes to the 'flapper valve' or, more properly (because I looked it up!) the 'Base Valve Gasket', which is part # 16 in the parts diagram in the link below." The joker valve is in the fitting that attaches the head discharge hose to the pump...once the waste gets through the joker valve, it's in the head discharge hose...no way can it go back through any part of the pump once it gets into the head discharge hose. Nor does the pump put any suction on a joker valve Pumping the toilet does not cause it to 'sucks' itself together, forming a seal"...it's just a rubber cup with a slit in it and "lips" on the outside that make it a one way valve--at least until the slit becomes so stretched by waste passing through it that it's become a gaping hole instead of a slit--that has only one function: to BLOCK a major backflow due to backpressure downstream of the toilet from flooding the bowl. It isn't supposed to prevent slow seepage, although a brand new one might for a short time. Whether the pump handle is left in the up or down position between uses makes no difference whatever. And flapper valves don't rotate...they're actually just a square flat "gasket" that has a weighted "tongue" (the flapper) dangling in the middle that causes it to function as a kind of one way valve, though not a very efficient one. Water backflow from the head discharge hose has no trouble getting past one into the bowl. You are correct, though, that removing the joker valve will have no impact whatever on whether the pump pushes waste out OR pulls flush water in. In fact, many owners of houseboats and other larger vessels that don't heel who want their toilets to hold water "like the one at home" remove the joker valve and install a loop in the head discharge line that's about as high as the bowl...allowing the water in the line between the toilet discharge and the top of the loop to run back into the bowl. Most manual marine toilets--good quality AND junk--have piston/cylinder pumps that all work pretty much the same way...the only major difference is how efficiently they do it and how durable they are: A piston rod inside a cylinder pulls water in on one stroke and pushes it out on the other stroke. Manual toilets are “double-action”, that is both sides of the piston are used simultaneously for different purposes. When you pull the pump piston up, a vacuum is created in the space below the piston which pulls some of the contents from the toilet bowl and into the bottom half of the pump cylinder. Then, when you push it down, a pair of built-in valves (the flapper valves you referred to) reverses and the material is pushed out of the bottom half of the pump, through the joker valve and on to a holding tank, treatment system, overboard or other ultimate destination. When you pull up on the pump in the "wet" mode, any water in the top of the cylinder is expelled through a flapper valve and connecting hose, to the entry point at the rear of the toilet bowl to rinse the bowl. Pushing the handle down creates a vacuum in the top half of the cylinder and pulls in outside water, filling the empty space above the piston. So you're bringing in outside water for flushing and delivering it to the bowl for rinsing at the same time the contents of the bowl are being pulled out and sent on their way. The "dry/flush" lever or knob near the top of the toilet pump operates a valve that opens (flush) or blocks (dry) the flow of flush water from the top of the pump. In the “wet” mode, the pump pulls water in from outside to rinse the bowl, while simultaneously pushing the contents out of the bowl and pumping them downstream. In the “dry” mode, it only pushes bowl contents out. While in the “dry” mode, air pressure created by pumping a manual toilet that is in good condition can move waste and water through the system up to about 6 feet without bringing in any flush water. So, Mike...if you want your head discharge line to be empty, you might try pumping longer in the dry mode. If the uphill run to the tank is much more than about 6', consider putting a loop in the line that's closer to the toilet and slightly above the tank...flush long enough to get bowl contents over the top of the loop and let gravity get it the rest of the way to the tank. On sailboats there really should have a loop in the line anyway...to prevent waste in the tank that gets into the line when you're heeled from getting back to the toilet. Meanwhile, when the boat will sit, follow the clean water with a cupful of white vinegar flushed all the way through to the tank to prevent sea water mineral buildup in the pump, joker valve and head discharge hose. As for the original poster's problem... His bowl is filling up almost immediately after flushing...so if it really is backflow of bowl contents, the first thing I'd check is the tank vent line.
You said, "Where does the water from the discharge hose GO, once it gets past the Joker valve? If you said: 'Into the tank', you'd be wrong. It goes to the 'flapper valve' or, more properly (because I looked it up!) the 'Base Valve Gasket', which is part # 16 in the parts diagram in the link below." The joker valve is in the fitting that attaches the head discharge hose to the pump...once the waste gets through the joker valve, it's in the head discharge hose...no way can it go back through any part of the pump once it gets into the head discharge hose. Nor does the pump put any suction on a joker valve Pumping the toilet does not cause it to 'sucks' itself together, forming a seal"...it's just a rubber cup with a slit in it and "lips" on the outside that make it a one way valve--at least until the slit becomes so stretched by waste passing through it that it's become a gaping hole instead of a slit--that has only one function: to BLOCK a major backflow due to backpressure downstream of the toilet from flooding the bowl. It isn't supposed to prevent slow seepage, although a brand new one might for a short time. Whether the pump handle is left in the up or down position between uses makes no difference whatever. And flapper valves don't rotate...they're actually just a square flat "gasket" that has a weighted "tongue" (the flapper) dangling in the middle that causes it to function as a kind of one way valve, though not a very efficient one. Water backflow from the head discharge hose has no trouble getting past one into the bowl. You are correct, though, that removing the joker valve will have no impact whatever on whether the pump pushes waste out OR pulls flush water in. In fact, many owners of houseboats and other larger vessels that don't heel who want their toilets to hold water "like the one at home" remove the joker valve and install a loop in the head discharge line that's about as high as the bowl...allowing the water in the line between the toilet discharge and the top of the loop to run back into the bowl. Most manual marine toilets--good quality AND junk--have piston/cylinder pumps that all work pretty much the same way...the only major difference is how efficiently they do it and how durable they are: A piston rod inside a cylinder pulls water in on one stroke and pushes it out on the other stroke. Manual toilets are “double-action”, that is both sides of the piston are used simultaneously for different purposes. When you pull the pump piston up, a vacuum is created in the space below the piston which pulls some of the contents from the toilet bowl and into the bottom half of the pump cylinder. Then, when you push it down, a pair of built-in valves (the flapper valves you referred to) reverses and the material is pushed out of the bottom half of the pump, through the joker valve and on to a holding tank, treatment system, overboard or other ultimate destination. When you pull up on the pump in the "wet" mode, any water in the top of the cylinder is expelled through a flapper valve and connecting hose, to the entry point at the rear of the toilet bowl to rinse the bowl. Pushing the handle down creates a vacuum in the top half of the cylinder and pulls in outside water, filling the empty space above the piston. So you're bringing in outside water for flushing and delivering it to the bowl for rinsing at the same time the contents of the bowl are being pulled out and sent on their way. The "dry/flush" lever or knob near the top of the toilet pump operates a valve that opens (flush) or blocks (dry) the flow of flush water from the top of the pump. In the “wet” mode, the pump pulls water in from outside to rinse the bowl, while simultaneously pushing the contents out of the bowl and pumping them downstream. In the “dry” mode, it only pushes bowl contents out. While in the “dry” mode, air pressure created by pumping a manual toilet that is in good condition can move waste and water through the system up to about 6 feet without bringing in any flush water. So, Mike...if you want your head discharge line to be empty, you might try pumping longer in the dry mode. If the uphill run to the tank is much more than about 6', consider putting a loop in the line that's closer to the toilet and slightly above the tank...flush long enough to get bowl contents over the top of the loop and let gravity get it the rest of the way to the tank. On sailboats there really should have a loop in the line anyway...to prevent waste in the tank that gets into the line when you're heeled from getting back to the toilet. Meanwhile, when the boat will sit, follow the clean water with a cupful of white vinegar flushed all the way through to the tank to prevent sea water mineral buildup in the pump, joker valve and head discharge hose. As for the original poster's problem... His bowl is filling up almost immediately after flushing...so if it really is backflow of bowl contents, the first thing I'd check is the tank vent line.
I meant water seeping back into the pump......
as that's the subject matter. Sorry for the ambiguity. If you read it again, it should make more sense. Since you agree that the Joker Valve won't stop water from seeping back into the toilet, and you don't think the 'flapper valve' will, then what does? I believe that 'flapper valve' is more important than you think - if it doesn't seal well, then the pump down-stroke will push water/waste back into the bowl as well as into the discharge hose, and along with waste coming back up into the bowl, the loss of pressure forcing the water/waste into the discharge hose will prevent good flow to the tank or over the vented loop. Certainly, if the 'flapper valve' doesn't seal well, it will prevent clearing the bowl, prevent clearing the discharge hose AND allow water/waste to seep back into the bowl. So Mike can pump all day if he wants to, but if his 'flapper valve' isn't seating well, he's not going to develop enough pressure to clear the discharge hose, is he? One other item: on the pump up-stroke, the 'vacuum' that is created most certainly DOES cause the Joker Valve to 'suck in' and at least partially seal the entrance to the discharge hose. Otherwise, water/waste already in the discharge hose would be drawn back into the pump, which would also cut down on the efficiency of the pump. Cheers, Bob s/v X SAIL R 8
as that's the subject matter.
Sorry for the ambiguity. If you read it again, it should make more sense. Since you agree that the Joker Valve won't stop water from seeping back into the toilet, and you don't think the 'flapper valve' will, then what does? I believe that 'flapper valve' is more important than you think - if it doesn't seal well, then the pump down-stroke will push water/waste back into the bowl as well as into the discharge hose, and along with waste coming back up into the bowl, the loss of pressure forcing the water/waste into the discharge hose will prevent good flow to the tank or over the vented loop. Certainly, if the 'flapper valve' doesn't seal well, it will prevent clearing the bowl, prevent clearing the discharge hose AND allow water/waste to seep back into the bowl. So Mike can pump all day if he wants to, but if his 'flapper valve' isn't seating well, he's not going to develop enough pressure to clear the discharge hose, is he? One other item: on the pump up-stroke, the 'vacuum' that is created most certainly DOES cause the Joker Valve to 'suck in' and at least partially seal the entrance to the discharge hose. Otherwise, water/waste already in the discharge hose would be drawn back into the pump, which would also cut down on the efficiency of the pump. Cheers, Bob s/v X SAIL R 8
You're confusing two different things, Bob
The flapper valve is very important when it comes to pulling flush water in and pushing waste out, but has little if anything to do with preventing backflow. You asked, "Since you agree that the Joker Valve won't stop water from seeping back into the toilet, and you don't think the 'flapper valve' will, then what does?" Nothing will. Water runs downhill, so if there's any in a line that runs uphill from the toilet, it's eventually gonna make it back into the bowl. The only variable is the speed at which that happens, determined by the condition of the joker valve. And finally you said, "on the pump up-stroke, the 'vacuum' that is created most certainly DOES cause the Joker Valve to 'suck in' and at least partially seal the entrance to the discharge hose. Otherwise, water/waste already in the discharge hose would be drawn back into the pump, which would also cut down on the efficiency of the pump." Nope...if that were true, removing the joker valve to keep water in the bowl would make it impossible to flush a toilet without pulling waste back into the bowl with each stroke. But that doesn't happen...only the flush water left in the line between the toilet discharge and the top of loop ends up back in the bowl, and that only happens AFTER the user stops pumping. Of course, if the user stops pumping before all the waste has cleared the top of the loop, it's gonna be waste, not water, that ends up back in the bowl. But the only thing that's putting it back in the bowl is gravity. If you take a close look at a joker valve, you'll see that there's nothing that can be "sucked in"...it's just a cup with a slit in it. Any suction against that slit would only pull liquid back through the slit...which becomes microscopically more open with each flush through it...and why joker valves should be replaced at least every two years, preferably annually.
The flapper valve is very important when it comes to pulling flush water in and pushing waste out, but has little if anything to do with preventing backflow. You asked, "Since you agree that the Joker Valve won't stop water from seeping back into the toilet, and you don't think the 'flapper valve' will, then what does?" Nothing will. Water runs downhill, so if there's any in a line that runs uphill from the toilet, it's eventually gonna make it back into the bowl. The only variable is the speed at which that happens, determined by the condition of the joker valve. And finally you said, "on the pump up-stroke, the 'vacuum' that is created most certainly DOES cause the Joker Valve to 'suck in' and at least partially seal the entrance to the discharge hose. Otherwise, water/waste already in the discharge hose would be drawn back into the pump, which would also cut down on the efficiency of the pump." Nope...if that were true, removing the joker valve to keep water in the bowl would make it impossible to flush a toilet without pulling waste back into the bowl with each stroke. But that doesn't happen...only the flush water left in the line between the toilet discharge and the top of loop ends up back in the bowl, and that only happens AFTER the user stops pumping. Of course, if the user stops pumping before all the waste has cleared the top of the loop, it's gonna be waste, not water, that ends up back in the bowl. But the only thing that's putting it back in the bowl is gravity. If you take a close look at a joker valve, you'll see that there's nothing that can be "sucked in"...it's just a cup with a slit in it. Any suction against that slit would only pull liquid back through the slit...which becomes microscopically more open with each flush through it...and why joker valves should be replaced at least every two years, preferably annually.
Nigel Calder agrees with me.....
well, that sounds a bit egotistical, but I didn't look at his 'Boatowners Mechanical and Electrical Guide' until your last post showed up, so everything I have posted so far is my own opinion. On page 548, in Figure 12-33A, 'The operation of a double-acting piston toilet', the up-stroke drawing has captions 'joker valve sucked shut' and 'flap valve sucked open'. In the text on the same page, it reads: 'A joker valve is a silt rubber hemisphere, to the convex surface of which is attached a rubber sleeve (the duck's bill). Fluid pushing through the base of the hemisphere opens hte slit and sleeve; fluid approaching the hemisphere from the other side collapses and closes it'. If the flapper valve is working properly, water from the discharge hose will not get past it to seep back into the bowl. Since this is usually below the bottom of the bowl, the water has to push DOWN on it (in the Jabsco configuration, as well as the Raritan, as I recall) and down is closed, so the weight of the water helps keep it closed. I don't want to make a big thing about this, but I didn't say that removing the joker valve would make anything 'impossible'. I DID say that if the joker valve is missing, the pump will be less efficient. Look at it this way: On the up-stroke, the pump barrel has two sources for filling itself (which it is trying to do by creating the 'vacuum'): a) the bowl and b) whatever is in the discharge hose. The flapper valve rotates UP (yes, it does indeed rotate about its attachment point) allowing water/waste from the bowl to enter the pump barrel. If the joker valve is not present, any water/waste in the discharge hose will ALSO be sucked up into the pump barrel. On the down-stroke, the flapper valve rotates DOWN, sealing the bowl and directing the water/waste somewhere else, into the discharge hose. Without a flapper valve, the proportion of bowl water to discharge hose water will probably be somewhat equal. WITH a flapper valve, it will probably be more than 90% bowl water..... therefore, the pump will be more efficient. Those house-boat owners who remove their joker valves are doing a lot of extra pumping, as far as I can see. Cheers, Bob s/v X SAIL R 8
well, that sounds a bit egotistical, but I didn't look at his 'Boatowners Mechanical and Electrical Guide' until your last post showed up, so everything I have posted so far is my own opinion.
On page 548, in Figure 12-33A, 'The operation of a double-acting piston toilet', the up-stroke drawing has captions 'joker valve sucked shut' and 'flap valve sucked open'. In the text on the same page, it reads: 'A joker valve is a silt rubber hemisphere, to the convex surface of which is attached a rubber sleeve (the duck's bill). Fluid pushing through the base of the hemisphere opens hte slit and sleeve; fluid approaching the hemisphere from the other side collapses and closes it'. If the flapper valve is working properly, water from the discharge hose will not get past it to seep back into the bowl. Since this is usually below the bottom of the bowl, the water has to push DOWN on it (in the Jabsco configuration, as well as the Raritan, as I recall) and down is closed, so the weight of the water helps keep it closed. I don't want to make a big thing about this, but I didn't say that removing the joker valve would make anything 'impossible'. I DID say that if the joker valve is missing, the pump will be less efficient. Look at it this way: On the up-stroke, the pump barrel has two sources for filling itself (which it is trying to do by creating the 'vacuum'): a) the bowl and b) whatever is in the discharge hose. The flapper valve rotates UP (yes, it does indeed rotate about its attachment point) allowing water/waste from the bowl to enter the pump barrel. If the joker valve is not present, any water/waste in the discharge hose will ALSO be sucked up into the pump barrel. On the down-stroke, the flapper valve rotates DOWN, sealing the bowl and directing the water/waste somewhere else, into the discharge hose. Without a flapper valve, the proportion of bowl water to discharge hose water will probably be somewhat equal. WITH a flapper valve, it will probably be more than 90% bowl water..... therefore, the pump will be more efficient. Those house-boat owners who remove their joker valves are doing a lot of extra pumping, as far as I can see. Cheers, Bob s/v X SAIL R 8
Bob, why don't you remove the joker valve from
your own toilet, and pump some clean water through it so you can see for yourself what happens. It's prob'ly time you changed it anyway. I've met Nigel...nobody's better at diesel engines than he is, but he and the toilet mfrs disagree about how they work. For one thing, there is no sleeve on joker valve...it's a molded rubber doodad. Just how old IS your copy of his book??? "I DID say that if the joker valve is missing, the pump will be less efficient." Not true. But you're not gonna believe that unless you do pump the toilet without one installed, so there's no point in my continuing to try to convince you.
your own toilet, and pump some clean water through it so you can see for yourself what happens. It's prob'ly time you changed it anyway. I've met Nigel...nobody's better at diesel engines than he is, but he and the toilet mfrs disagree about how they work. For one thing, there is no sleeve on joker valve...it's a molded rubber doodad. Just how old IS your copy of his book??? "I DID say that if the joker valve is missing, the pump will be less efficient." Not true. But you're not gonna believe that unless you do pump the toilet without one installed, so there's no point in my continuing to try to convince you.
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