Hi Peggy and everybody else, I did my research and I'm still confused about the subject of vented loops. Let me make some assertions: 1. A vented loop is required between the intake pump and the bowl IF the toilet is below the waterline at any angle of heel. 2. A vented loop is required between the holding tank and thru-hull for discharge IF the toilet is below the waterline at any angle of heel. 3. A vented loop is required between the toilet and the holding tank if the toilet is bolow the top of the holding tank at any time. My source for these assertions is both Jabsco and Raritan PHII installation manuals. Can I get agreement/opinions/disagreement on these 3 assertions? There's a couple of other items I would like to discuss, but this is the most important one, because I just ordered 2 vented loops. Cheers, Bob s/v X SAIL R 8
- Status
Yes, no, no...
But first... "required" isn't the right word here. It implies some kind of mandatory legal "building code." There is no legal REQUIREMENT to install vented loops in any line, its just one of many voluntary safety standards that prudent owners follow. So I'm gonna change your word "required" to "needed." 1. Yes, a vented loop is needed between the intake pump and the bowl IF the toilet is below the waterline at any angle of heel. "2. A vented loop is needed between the holding tank and thru-hull for discharge IF the toilet is below the waterline at any angle of heel." No. A vented loop is needed between the tank and the thru-hull if the TANK or any part of it is below the waterline...the orientation of the toilet relative to the waterline has nothing to do with whether a vented loop is needed in a line that isn't even connected to the toilet. "3. A vented loop is needed between the toilet and the holding tank if the toilet is bolow the top of the holding tank at any time." No. A vented loop is not needed between the toilet and the tank at all. The whole purpose of a vented loop is to prevent water OUTside the boat from finding its own level INside the boat. They serve no useful purpose whatever in any line that isn't connected to a below-waterline thru-hull. So if the toilet only flushes into the tank, no vented loop in the head discharge line is needed. If there's a y-valve in the head discharge line that provides a choice of flushing directly overboard at sea or into the tank, a vented loop should be installed between the y-valve and the thru-hull.
But first... "required" isn't the right word here. It implies some kind of mandatory legal "building code." There is no legal REQUIREMENT to install vented loops in any line, its just one of many voluntary safety standards that prudent owners follow. So I'm gonna change your word "required" to "needed." 1. Yes, a vented loop is needed between the intake pump and the bowl IF the toilet is below the waterline at any angle of heel. "2. A vented loop is needed between the holding tank and thru-hull for discharge IF the toilet is below the waterline at any angle of heel." No. A vented loop is needed between the tank and the thru-hull if the TANK or any part of it is below the waterline...the orientation of the toilet relative to the waterline has nothing to do with whether a vented loop is needed in a line that isn't even connected to the toilet. "3. A vented loop is needed between the toilet and the holding tank if the toilet is bolow the top of the holding tank at any time." No. A vented loop is not needed between the toilet and the tank at all. The whole purpose of a vented loop is to prevent water OUTside the boat from finding its own level INside the boat. They serve no useful purpose whatever in any line that isn't connected to a below-waterline thru-hull. So if the toilet only flushes into the tank, no vented loop in the head discharge line is needed. If there's a y-valve in the head discharge line that provides a choice of flushing directly overboard at sea or into the tank, a vented loop should be installed between the y-valve and the thru-hull.
Ok, I'll admit I'm confused again.
I agree that the loop is needed between the intake pump and bowl. You can’t depend on the wet/dry valve to hold back the ocean. (I don’t have one on my boat at this time but I’m going to add one. Currently the seacock is easy to reach so it’s standing order that it is to be closed until needed.) Regarding the line between the head and the holding tank; haven’t you always pointed out that you shouldn’t depend on the joker valve to prevent backflow into the toilet? Therefore, a vented loop is needed so that on some angles of heal the toilet doesn’t fill or overflow from the contents of the tank. Last year, here in Texas, new rules came into effect that require the removal of any discharge plumbing connected to through hulls. There must be no way to discharge overboard. Simply removing the valve handle or wiring it closed is no longer sufficient. I did that last summer. This fall I was going to replace hoses that are beginning to permeate. However, my boat came to me with a vented loop between the toilet and the Y valve. If I don’t need the vented loop it will save several feet of hose! Are you sure I can do without it? Thanks, Dennis Thomas S/V Anodyne
I agree that the loop is needed between the intake pump and bowl. You can’t depend on the wet/dry valve to hold back the ocean. (I don’t have one on my boat at this time but I’m going to add one. Currently the seacock is easy to reach so it’s standing order that it is to be closed until needed.) Regarding the line between the head and the holding tank; haven’t you always pointed out that you shouldn’t depend on the joker valve to prevent backflow into the toilet? Therefore, a vented loop is needed so that on some angles of heal the toilet doesn’t fill or overflow from the contents of the tank. Last year, here in Texas, new rules came into effect that require the removal of any discharge plumbing connected to through hulls. There must be no way to discharge overboard. Simply removing the valve handle or wiring it closed is no longer sufficient. I did that last summer. This fall I was going to replace hoses that are beginning to permeate. However, my boat came to me with a vented loop between the toilet and the Y valve. If I don’t need the vented loop it will save several feet of hose! Are you sure I can do without it? Thanks, Dennis Thomas S/V Anodyne
OK, 1
with the correction by Peggy on #2: 2. A vented loop is required between the intake pump and the bowl IF the HOLDING TANK is below the waterline at any angle of heel. This is progress. My next post will discuss #3. Cheers, Bob s/v X SAIL R 8
with the correction by Peggy on #2: 2. A vented loop is required between the intake pump and the bowl IF the HOLDING TANK is below the waterline at any angle of heel. This is progress. My next post will discuss #3. Cheers, Bob s/v X SAIL R 8
Needed, not stirred, um shaken, um...
Re-reading your post, Peggy, I agree that required is not the best term. Needed is better - I'll use necessary. #1 A vented loop is necessary between the intake pump and the bowl IF the toilet is below the waterline at any angle of heel. #2. A vented loop is necessary between the intake pump and the bowl IF the HOLDING TANK is below the waterline at any angle of heel. OK, there we are. BTW, the Commodore gets upset when I get so nit-noid picky about making everything perfect, but I'm an engineer and I find it necessary. My client's don't complain when their software performs exactly according toe the specifications. Cheers, Bob s/v X SAIL R 8
Re-reading your post, Peggy, I agree that required is not the best term. Needed is better - I'll use necessary. #1 A vented loop is necessary between the intake pump and the bowl IF the toilet is below the waterline at any angle of heel. #2. A vented loop is necessary between the intake pump and the bowl IF the HOLDING TANK is below the waterline at any angle of heel. OK, there we are. BTW, the Commodore gets upset when I get so nit-noid picky about making everything perfect, but I'm an engineer and I find it necessary. My client's don't complain when their software performs exactly according toe the specifications. Cheers, Bob s/v X SAIL R 8
Assertion #3
Now let's look at #3: A vented loop is necessary between the toilet and the holding tank if the toilet is below the top of the holding tank at any time. Referring to the Raritan owner's manual http://www.raritaneng.com/pdf_files/ph_II/L04phiiv0102.pdf and the Jabsco owner's manual http://www.jabsco.com/prodInfo/overview/29120_MANUAL_TOILET.PDF We find that both companies include a vented loop between the toilet discharge and the holding tank when the run is uphill to the holding tank. Additionally, Jabsco makes this statement: "If there is ANY possibility that the discharge elbow may be below the top of the tank at ANY time, a ventilated anti-syphon loop must be fitted in the outlet pipework to ensure that the contents of the tank do not syphon out through the bowl." Raritan chimes in with: "Route discharge hose above discharge outlet with a vented loop. This will enable the toilet to discharge more efficiently and will help to prevent backflow." I contend that these statements, combined with the diagrams in both user's manuals, show a necessity for the vented loop and validate Assertion #3. Comments? Next, I'd like to look at the why? of this vented loop and what happens in the discharge elbow and hose. Stay tuned. Cheers, Bob s/v X SAIL R 8
Now let's look at #3: A vented loop is necessary between the toilet and the holding tank if the toilet is below the top of the holding tank at any time. Referring to the Raritan owner's manual http://www.raritaneng.com/pdf_files/ph_II/L04phiiv0102.pdf and the Jabsco owner's manual http://www.jabsco.com/prodInfo/overview/29120_MANUAL_TOILET.PDF We find that both companies include a vented loop between the toilet discharge and the holding tank when the run is uphill to the holding tank. Additionally, Jabsco makes this statement: "If there is ANY possibility that the discharge elbow may be below the top of the tank at ANY time, a ventilated anti-syphon loop must be fitted in the outlet pipework to ensure that the contents of the tank do not syphon out through the bowl." Raritan chimes in with: "Route discharge hose above discharge outlet with a vented loop. This will enable the toilet to discharge more efficiently and will help to prevent backflow." I contend that these statements, combined with the diagrams in both user's manuals, show a necessity for the vented loop and validate Assertion #3. Comments? Next, I'd like to look at the why? of this vented loop and what happens in the discharge elbow and hose. Stay tuned. Cheers, Bob s/v X SAIL R 8
Exploring the need for a vented loop
So why do we need this vented loop between the toilet and the holding tank, anyway? Here's what I gleaned out of the manuals previously referenced. A. "...to ensure that the contents of the tank do not syphon out through the bowl..." Jabsco B. "...to discharge more efficiently and will help to prevent backflow..." Raritan Those were easy, they were in my last post. Now let's dig a little deeper... My particular problem has to do with backflow (water seeping back into the bowl from the discharge hose), so I looked at the Raritan troubleshooting guide. "Water rises in bowl at dockside (toilet below waterline)." Two of the probable causes involve the intake side (not my problem) and the third is: "Joker valve leaking." The correction is: "...Clean or replace joker valve. A vented loop is needed in the discharge." Right above that is "Water accumulates in the bowl too fast." and the probable cause is "Joker Valve not closing or opening properly." Corrective action: "Close intake valve and pump dry. Clean or replace joker valve. NOTE: Routing discharge hose above toilet helps joker valve close tighter." And the note is in BOLD in the manual. The only possible explanation I can find for this note is that there is water in the discharge hose that presses on the joker valve to help it close. From the Raritan user's manual: "Pumping several strokes after the bowl has been flushed will help to clear the lines, minimize odor and reduce the possibility of backflow into the bowl." From Jabsco: "After use, keep the Flush Control shut and pump until the bowl is empty. When the bowl is empty, open the Flush Control again, and continue to pump until all waste has either left the boat, or reached the holding tank (allow 7 complete up/down strokes per metre (yard) length of discharge pipework Then shut the Flush Control and pump until the bowl is empty. Always leave the bowl empty to minimise odour and spillage." And finally, from Jabsco, referring to the advantages of having a loop in the discharge line even when the toilet is above the holding tank: "This will create a water seal at the Joker Valve that will prevent bad odours from escaping through the toilet." So Jabsco and Raritan agree on these issues. That leads me to 2 more assertions: 4. When the hose from the discharge elbow on the toilet to the holding tank runs up-hill, there is normally water in the hose. 5. The water in the hose helps seal the Joker Valve, so having a vented loop will increase the pressure, therefore the seal. There, that was fun! Comments? Cheers, Bob s/v X SAIL R 8
So why do we need this vented loop between the toilet and the holding tank, anyway? Here's what I gleaned out of the manuals previously referenced. A. "...to ensure that the contents of the tank do not syphon out through the bowl..." Jabsco B. "...to discharge more efficiently and will help to prevent backflow..." Raritan Those were easy, they were in my last post. Now let's dig a little deeper... My particular problem has to do with backflow (water seeping back into the bowl from the discharge hose), so I looked at the Raritan troubleshooting guide. "Water rises in bowl at dockside (toilet below waterline)." Two of the probable causes involve the intake side (not my problem) and the third is: "Joker valve leaking." The correction is: "...Clean or replace joker valve. A vented loop is needed in the discharge." Right above that is "Water accumulates in the bowl too fast." and the probable cause is "Joker Valve not closing or opening properly." Corrective action: "Close intake valve and pump dry. Clean or replace joker valve. NOTE: Routing discharge hose above toilet helps joker valve close tighter." And the note is in BOLD in the manual. The only possible explanation I can find for this note is that there is water in the discharge hose that presses on the joker valve to help it close. From the Raritan user's manual: "Pumping several strokes after the bowl has been flushed will help to clear the lines, minimize odor and reduce the possibility of backflow into the bowl." From Jabsco: "After use, keep the Flush Control shut and pump until the bowl is empty. When the bowl is empty, open the Flush Control again, and continue to pump until all waste has either left the boat, or reached the holding tank (allow 7 complete up/down strokes per metre (yard) length of discharge pipework Then shut the Flush Control and pump until the bowl is empty. Always leave the bowl empty to minimise odour and spillage." And finally, from Jabsco, referring to the advantages of having a loop in the discharge line even when the toilet is above the holding tank: "This will create a water seal at the Joker Valve that will prevent bad odours from escaping through the toilet." So Jabsco and Raritan agree on these issues. That leads me to 2 more assertions: 4. When the hose from the discharge elbow on the toilet to the holding tank runs up-hill, there is normally water in the hose. 5. The water in the hose helps seal the Joker Valve, so having a vented loop will increase the pressure, therefore the seal. There, that was fun! Comments? Cheers, Bob s/v X SAIL R 8
So, Peggie...
My system is: 1. Raw water intake to head 2. Head to holding tank 3. Holding tank to Y-valve to... 3a. Deck pump-out 3b. Macerator to overboard thru-hull What you're saying is that I can remove my vented loop from the head to the holding tank, but I should install one between the Y-valve and the thru-hull (3b)? Cheers, Bob Nonsuch 30C #77 Lazybones
My system is: 1. Raw water intake to head 2. Head to holding tank 3. Holding tank to Y-valve to... 3a. Deck pump-out 3b. Macerator to overboard thru-hull What you're saying is that I can remove my vented loop from the head to the holding tank, but I should install one between the Y-valve and the thru-hull (3b)? Cheers, Bob Nonsuch 30C #77 Lazybones
That's about right...
But you left out the vented loop in the head intake (between the pump and bowl). That one is needed in all toilets that are at or below the waterline, to prevent sea water from flooding the bowl if the wet/dry valve is left in the wet position or fails. Unless heeling can spill tank contents into the head discharge line to run back toward the toilet, no loop in the line between the toilet and tank is needed. If heeling does send waste back toward the toilet, there are two ways to solve that problem: 1. a LOOP--though not necessarily vented, 'cuz it's highly unlikely that any siphon can get started that way--that's high enough to keep tank contents from getting over it; 2. Move the inlet fitting--and vent fitting too--on the tank away from the hull (downhill side of the tank when you're heeled on that tack) to the side of the tank (vertical wall or top) closest to the centerline of the boat. When you heel to one tack, tank contents flow away from the inlet and vent fittings...on the other tack, the vent line and head discharge line run uphill. Aussie Globe http://www.aussieglobe.com makes a li'l doodad called the Uniseal that makes installing a new a tank fitting a piece of cake--and they're incredibly inexpensive, too. Threaded plugs--available from any hardware store--are all that's needed to close up the old ones.
But you left out the vented loop in the head intake (between the pump and bowl). That one is needed in all toilets that are at or below the waterline, to prevent sea water from flooding the bowl if the wet/dry valve is left in the wet position or fails. Unless heeling can spill tank contents into the head discharge line to run back toward the toilet, no loop in the line between the toilet and tank is needed. If heeling does send waste back toward the toilet, there are two ways to solve that problem: 1. a LOOP--though not necessarily vented, 'cuz it's highly unlikely that any siphon can get started that way--that's high enough to keep tank contents from getting over it; 2. Move the inlet fitting--and vent fitting too--on the tank away from the hull (downhill side of the tank when you're heeled on that tack) to the side of the tank (vertical wall or top) closest to the centerline of the boat. When you heel to one tack, tank contents flow away from the inlet and vent fittings...on the other tack, the vent line and head discharge line run uphill. Aussie Globe http://www.aussieglobe.com makes a li'l doodad called the Uniseal that makes installing a new a tank fitting a piece of cake--and they're incredibly inexpensive, too. Threaded plugs--available from any hardware store--are all that's needed to close up the old ones.
Assertion #1
#1 A vented loop is necessary between the intake pump and the bowl IF the toilet is below the waterline at any angle of heel. Bob, you need this vented loop if the TOILET is below the waterline at any time. The distinction you are making (citing the inlet through-hull) is not valid (IMHO) because the water pressure on the intake side of the potential siphon is determined by the waterline, not where the through-hull is. Peggy, did I get that one right? Cheers, Bob s/v X SAIL R 8
#1 A vented loop is necessary between the intake pump and the bowl IF the toilet is below the waterline at any angle of heel. Bob, you need this vented loop if the TOILET is below the waterline at any time. The distinction you are making (citing the inlet through-hull) is not valid (IMHO) because the water pressure on the intake side of the potential siphon is determined by the waterline, not where the through-hull is. Peggy, did I get that one right? Cheers, Bob s/v X SAIL R 8
Oops
Sorry, I mis-read your post, Bob. You were not suggesting removing the loop on the intake side, as I thought.
Sorry, I mis-read your post, Bob. You were not suggesting removing the loop on the intake side, as I thought.
Ok...which one of you Bobs is the engineer?
CA Bob, you got it right. Engineer Bob...you're a typical engineer--and so is my father, btw...that man actally put 2 hours of calculations into making sure that a shim for my Christmas tree stand was EXACTLY the right size and shape to ensure the tree would be perfectly vertical! <g> (God bless him, he just turned 90, and has barely lost a step!) Stop trying to OVER-engineer something that's just basic high school physics 101: liquids run downhill and water seeks its own level. Remember too that the plumbing that brings flush water INTO the toilet has nothing to do with the plumbing that sends it OUT of the toilet. If you don't want to end up with a system that'll cause you more "headaches" than it prevents, apply just those basics--and no more!--to your system design. It'll work, honest!
CA Bob, you got it right. Engineer Bob...you're a typical engineer--and so is my father, btw...that man actally put 2 hours of calculations into making sure that a shim for my Christmas tree stand was EXACTLY the right size and shape to ensure the tree would be perfectly vertical! <g> (God bless him, he just turned 90, and has barely lost a step!) Stop trying to OVER-engineer something that's just basic high school physics 101: liquids run downhill and water seeks its own level. Remember too that the plumbing that brings flush water INTO the toilet has nothing to do with the plumbing that sends it OUT of the toilet. If you don't want to end up with a system that'll cause you more "headaches" than it prevents, apply just those basics--and no more!--to your system design. It'll work, honest!
also guilty as charged
I like your solution of moving the waste tank intake fitting to the side opposite the head, but my tank is narrow and on the centerline. I'll remember it, though, for future reference. I also take your point that the toilet to holding tank loop does not have to be vented, but I'm going to put one in there anyway. My biggest problem with this loop is that, while you just might be right and the toilet pump will pump the contents of the discharge hose up over a loop (even though both head manufacturers don't think it will), I don't have any way to make the run from the loop to the tank all downhill.... and that is going to mean that there will always be water in that run. I'm going to have to re-think this loop. Cheers, Bob s/v X SAIL R 8
I like your solution of moving the waste tank intake fitting to the side opposite the head, but my tank is narrow and on the centerline. I'll remember it, though, for future reference. I also take your point that the toilet to holding tank loop does not have to be vented, but I'm going to put one in there anyway. My biggest problem with this loop is that, while you just might be right and the toilet pump will pump the contents of the discharge hose up over a loop (even though both head manufacturers don't think it will), I don't have any way to make the run from the loop to the tank all downhill.... and that is going to mean that there will always be water in that run. I'm going to have to re-think this loop. Cheers, Bob s/v X SAIL R 8
I didn't say opposite side from the head ...
I said away from the hull, toward the centerline. If the tank is on the centerline, put the fittings in the center of the tank. "Narrow and on the centerline"...where exactly is the tank going in the boat? "My biggest problem with this loop is that, while you just might be right and the toilet pump will pump the contents of the discharge hose up over a loop (even though both head manufacturers don't think it will)... Not true...the installation drawings in the manuals for both toilets show vented loops in discharge lines--lines that go overboard and lines to a tank. And I've seen a PH II on the bench at Raritan push waste over a loop more than 4 above it in the dry mode. Besides, vented loops are NEEDED in any head discharge line that discharges directly overboard....if the toilet couldn't pump bowl contents over the top of a vented loop in a line that goes to the tank, how could it pump bowl contents over the top of loop connected to a thru-hull? Btw...this is a direct quote from Vic Willman, tech services manager at Raritan: "While in the “dry” mode, air pressure reated 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."
I said away from the hull, toward the centerline. If the tank is on the centerline, put the fittings in the center of the tank. "Narrow and on the centerline"...where exactly is the tank going in the boat? "My biggest problem with this loop is that, while you just might be right and the toilet pump will pump the contents of the discharge hose up over a loop (even though both head manufacturers don't think it will)... Not true...the installation drawings in the manuals for both toilets show vented loops in discharge lines--lines that go overboard and lines to a tank. And I've seen a PH II on the bench at Raritan push waste over a loop more than 4 above it in the dry mode. Besides, vented loops are NEEDED in any head discharge line that discharges directly overboard....if the toilet couldn't pump bowl contents over the top of a vented loop in a line that goes to the tank, how could it pump bowl contents over the top of loop connected to a thru-hull? Btw...this is a direct quote from Vic Willman, tech services manager at Raritan: "While in the “dry” mode, air pressure reated 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."
Now I'm curious
Hi Peggy, and I'm contemplating temporarily installing a piece of clear hose between the discharge of the toilet and the vented loop, just to see for myself what you saw. My boat is a Hunter 31 and the holding tank is directly under the v-berth. You wrote: "Besides, vented loops are NEEDED in any head discharge line that discharges directly overboard....if the toilet couldn't pump bowl contents over the top of a vented loop in a line that goes to the tank, how could it pump bowl contents over the top of loop connected to a thru-hull?" If I am pumping directly overboard, there is no need to put the switch to dry.... I pump on wet till the bowl is evacuated and then more until the waste is out of the boat. If I don't want to leave water in the bowl, I switch to dry and empty it. Perhaps I should take this subject up directly with Raritan or Jabsco, rather than contributing to your Tylenol usage. I guess my confusion is that what you and Mr. Willman are saying is directly contradictory to what both user manuals say on the subject. (Please refer to my long post titled 'Exploring the need for a vented loop' in this thread). It seems to me that the manuals want me to pump the waste all the way to the bowl in wet mode, then empty the bowl in dry. They both also extol the virtues of having a column of water (clean, not waste) in the discharge tube to help seal the Joker Valve. Please read that post and tell me where I am going wrong? If the pump is able to blow MOST, but not all of the water over the loop, the remaining column of water may not be adequate to seal the Joker Valve, which would then contribute to the seepage problem, not prevent it. I guess I'll have to experiment on this one myself. Cheers, Bob s/v X SAIL R 8
Hi Peggy, and I'm contemplating temporarily installing a piece of clear hose between the discharge of the toilet and the vented loop, just to see for myself what you saw. My boat is a Hunter 31 and the holding tank is directly under the v-berth. You wrote: "Besides, vented loops are NEEDED in any head discharge line that discharges directly overboard....if the toilet couldn't pump bowl contents over the top of a vented loop in a line that goes to the tank, how could it pump bowl contents over the top of loop connected to a thru-hull?" If I am pumping directly overboard, there is no need to put the switch to dry.... I pump on wet till the bowl is evacuated and then more until the waste is out of the boat. If I don't want to leave water in the bowl, I switch to dry and empty it. Perhaps I should take this subject up directly with Raritan or Jabsco, rather than contributing to your Tylenol usage. I guess my confusion is that what you and Mr. Willman are saying is directly contradictory to what both user manuals say on the subject. (Please refer to my long post titled 'Exploring the need for a vented loop' in this thread). It seems to me that the manuals want me to pump the waste all the way to the bowl in wet mode, then empty the bowl in dry. They both also extol the virtues of having a column of water (clean, not waste) in the discharge tube to help seal the Joker Valve. Please read that post and tell me where I am going wrong? If the pump is able to blow MOST, but not all of the water over the loop, the remaining column of water may not be adequate to seal the Joker Valve, which would then contribute to the seepage problem, not prevent it. I guess I'll have to experiment on this one myself. Cheers, Bob s/v X SAIL R 8
No contradiction...
From page 3 of the Raritan PH II manual, which you can find here http://www.raritaneng.com/pdf_files/ph_II/L04phiiv0102.pdf: PLUMBING WARNING: Below waterline installations require vented loops. Top of the loop must be above waterline at greatest angle of heel. Intake vented loops must be installed between pump and back of the bowl. Discharge vented loops must be installed between the discharge of toilet and seacock. See Fig. #1 and #1A. 1. Route discharge hose above discharge outlet with a vented loop. This will enable the toilet to discharge more efficiently and will help to prevent backflow. From page 3 of the Jabsco manual toilet manual http://www.jabsco.com/prodInfo/overview/29090_MANUAL_TOILET.PDF Option 3: Toilet waste discharging into holding tank, top of holding tank above discharge elbow at anytime. (See Figure 3 below) YOU MUST fit a 38mm (11/2") Vented loop fitting, Jabsco part number 29015-0010. If there is ANY possibility that the discharge elbow may be below the top of the tank at ANY time, a ventilated anti-syphon loop must be fitted in the outlet pipework to ensure that the contents of the tank do not syphon out through the bowl. Arrange the outlet hose to form a loop which is at least 20 cm (8") above the highest possible level that the tank may reach, and fit the Vented Loop at that highest point. You said, "It seems to me that the manuals want me to pump the waste all the way to the bowl in wet mode..." You can do that if you don't mind filling up your tank with flush water. "...then empty the bowl in dry. They both also extol the virtues of having a column of water(clean, not waste) in the discharge tube to help seal the Joker Valve." Advice based on the assumption that a) it's inevitable that the holding tank contents will stink, and b) a "water break" is needed to keep holding tank odors from escaping through the head discharge line. But if the holding tank is maintained aerobically and the joker valve isn't so worn that the slit has become a gaping hole, it's not necessary. There's nothing WRONG with doing it their way if you don't mind filling up your tank with flush water, are willing to accept a holding tank that belches noxious gasses every time the head is flushed...fight a continual battle with smelly water seeping back into your bowl and rarely if ever intend to replace your joker valve. You said, "If the pump is able to blow MOST, but not all of the water over the loop, the remaining column of water may not be adequate to seal the Joker Valve, which would then contribute to the seepage problem, not prevent it." Water against a joker valve doesn't seal it...it only puts a water break--same as the P-trap in the toilet at home, but above instead of below. And since liquids run downhill--and no joker valve that's more than about a month old can completely block seepage, what it comes down to is this: Would you rather have the entire contents in the line from the toilet to the top of loop seeping back into the toilet through the joker valve...or only half a cup at most? "I'm contemplating temporarily installing a piece of clear hose between the discharge of the toilet and the vented loop, just to see for myself what you saw." You and my dad would get along like a house afire...you're just alike! What I saw was NOT water going through a clear hose...but a bowlful of water come out the other end of a looped hose into a sink! Only an engineer--and not very many of them!--would think of installing a "sight glass" in his head discharge line so he can watch his waste go through it instead of just flushing the toilet in the dry mode into a bucket after you've installed the upbound hose to the loop but before you install the downside. But even doing it the easy way, I'm sure you'll precisely measure the amount going in and use a beaker instead of a bucket to measure the exact amount of water that makes it over the top of the loop. Going off to find the bottle of Aleve now...it's too early in the day for scotch.
From page 3 of the Raritan PH II manual, which you can find here http://www.raritaneng.com/pdf_files/ph_II/L04phiiv0102.pdf: PLUMBING WARNING: Below waterline installations require vented loops. Top of the loop must be above waterline at greatest angle of heel. Intake vented loops must be installed between pump and back of the bowl. Discharge vented loops must be installed between the discharge of toilet and seacock. See Fig. #1 and #1A. 1. Route discharge hose above discharge outlet with a vented loop. This will enable the toilet to discharge more efficiently and will help to prevent backflow. From page 3 of the Jabsco manual toilet manual http://www.jabsco.com/prodInfo/overview/29090_MANUAL_TOILET.PDF Option 3: Toilet waste discharging into holding tank, top of holding tank above discharge elbow at anytime. (See Figure 3 below) YOU MUST fit a 38mm (11/2") Vented loop fitting, Jabsco part number 29015-0010. If there is ANY possibility that the discharge elbow may be below the top of the tank at ANY time, a ventilated anti-syphon loop must be fitted in the outlet pipework to ensure that the contents of the tank do not syphon out through the bowl. Arrange the outlet hose to form a loop which is at least 20 cm (8") above the highest possible level that the tank may reach, and fit the Vented Loop at that highest point. You said, "It seems to me that the manuals want me to pump the waste all the way to the bowl in wet mode..." You can do that if you don't mind filling up your tank with flush water. "...then empty the bowl in dry. They both also extol the virtues of having a column of water(clean, not waste) in the discharge tube to help seal the Joker Valve." Advice based on the assumption that a) it's inevitable that the holding tank contents will stink, and b) a "water break" is needed to keep holding tank odors from escaping through the head discharge line. But if the holding tank is maintained aerobically and the joker valve isn't so worn that the slit has become a gaping hole, it's not necessary. There's nothing WRONG with doing it their way if you don't mind filling up your tank with flush water, are willing to accept a holding tank that belches noxious gasses every time the head is flushed...fight a continual battle with smelly water seeping back into your bowl and rarely if ever intend to replace your joker valve. You said, "If the pump is able to blow MOST, but not all of the water over the loop, the remaining column of water may not be adequate to seal the Joker Valve, which would then contribute to the seepage problem, not prevent it." Water against a joker valve doesn't seal it...it only puts a water break--same as the P-trap in the toilet at home, but above instead of below. And since liquids run downhill--and no joker valve that's more than about a month old can completely block seepage, what it comes down to is this: Would you rather have the entire contents in the line from the toilet to the top of loop seeping back into the toilet through the joker valve...or only half a cup at most? "I'm contemplating temporarily installing a piece of clear hose between the discharge of the toilet and the vented loop, just to see for myself what you saw." You and my dad would get along like a house afire...you're just alike!
What I saw was NOT water going through a clear hose...but a bowlful of water come out the other end of a looped hose into a sink! Only an engineer--and not very many of them!--would think of installing a "sight glass" in his head discharge line so he can watch his waste go through it instead of just flushing the toilet in the dry mode into a bucket after you've installed the upbound hose to the loop but before you install the downside. But even doing it the easy way, I'm sure you'll precisely measure the amount going in and use a beaker instead of a bucket to measure the exact amount of water that makes it over the top of the loop. Going off to find the bottle of Aleve now...it's too early in the day for scotch. He He He
Hi Peggy, I suppose I got the idea for the sight glass from the one on the pumpout fitting at our marina. I am also sort of interested in the interaction of the air and water in the column. If you ever saw "The Right Stuff" you'll remember the scene where the prospective astronauts were blowing into the tubes to keep the ball between the lines in the glass tubes of water. (The book was much better, BTW) I think that stuck in my memory, too. On the other hand, I'm chuckling about the simplicity of pouring a bucket of water in the bowl and then attempting to flush it out the open end of the vented loop..... (ok, I won't dissapoint you) but how will I know if it is ALL of the water? I have now (drum-roll, please....) explored enough to understand how your method differs from that of the manufacturers and why - and your's certainly sounds more efficient. I also feel that I understand the concepts involved pretty well, and am ready to tackle the mechanics of it, as soon as the parts for my vented loops arrive. And I appreciate your patience in helping me along my learning curve (which probably needs a vented loop in it, as well!!!). I'm glad you're getting to enjoy time with your father - mine's 80 and still captains his own tennis team. He sails too, and I've been working on getting him out here to sail to Catalina.... but before the winter weather sets in, hopefully. I am also happy that I am pretty well inured to bad odors, having lived in Egypt for 8 years and a lot of that time out in the Nile river delta..... that country smells bad, amongst other things!!! As to the relative merits of Advil versus GlenMorangie..... It's five o'clock somewhere!!!! Cheers, Bob s/v X SAIL R 8
Hi Peggy, I suppose I got the idea for the sight glass from the one on the pumpout fitting at our marina. I am also sort of interested in the interaction of the air and water in the column. If you ever saw "The Right Stuff" you'll remember the scene where the prospective astronauts were blowing into the tubes to keep the ball between the lines in the glass tubes of water. (The book was much better, BTW) I think that stuck in my memory, too. On the other hand, I'm chuckling about the simplicity of pouring a bucket of water in the bowl and then attempting to flush it out the open end of the vented loop..... (ok, I won't dissapoint you) but how will I know if it is ALL of the water? I have now (drum-roll, please....) explored enough to understand how your method differs from that of the manufacturers and why - and your's certainly sounds more efficient. I also feel that I understand the concepts involved pretty well, and am ready to tackle the mechanics of it, as soon as the parts for my vented loops arrive. And I appreciate your patience in helping me along my learning curve (which probably needs a vented loop in it, as well!!!). I'm glad you're getting to enjoy time with your father - mine's 80 and still captains his own tennis team. He sails too, and I've been working on getting him out here to sail to Catalina.... but before the winter weather sets in, hopefully. I am also happy that I am pretty well inured to bad odors, having lived in Egypt for 8 years and a lot of that time out in the Nile river delta..... that country smells bad, amongst other things!!! As to the relative merits of Advil versus GlenMorangie..... It's five o'clock somewhere!!!! Cheers, Bob s/v X SAIL R 8
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