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A tain breezer on poop! (GrandPAH)

you buy the beer, I'll spring for the meal!


  • seriously, a plumbing conundrum

    Anyone have any info on articles/info dealing with sewer blockages, their causes and how vertical lines differ from horizontal lines while clogs form????? Upcoming court case where I'd surely like to introduce "words" from others to back up my intended testimony.
  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728

    It's not your GrandPAH's toilet anymore (or something reminiscent of the Oldsmobile car ads). There is some info about this subject, but unfortunately I can't find it at the moment. I think a study was done by Stevens Institute and it involved low flow water saving toilets and the effect pitch within the "existing" sanitary drainage system played. I'll keep looking, but in the mean time you may want to contact Stevens. Stevens Institute has a whole building dedicated to this. I believe they call it the "crapper building" and it has in it all glass piping so they can observe flow.

    If I recall the issue written about recommended "less" pitch within the sanitary drainage system when using the mandated water saving bowls because when you used less water with the current requirement of a 1/4" inch to the foot pitch, the solids stayed behind while the water zoomed ahead, or something to that effect.

    Robert O'Connor/NJ
  • Brad White_156
    Brad White_156 Member Posts: 11
    2 FPS

    My former plumbing and sanitary systems instructor at Franklin Technical Institute in Boston, Mr. Joe Barbera, was well ahead of his time on this subject. Really knew his,... well,... material.

    He opined well before low flush toilets came on board how all pipe pitch in sanitary piping was based for a 2 FPS flow velocity and that by necessity meant that the water volume had to also be known. To arbitrarily change the water volume would require some modification of pitch. It is only rational, only physics. As Robert O'Connor pointed out, the velocity basis was critical lest the entire charge separate on the way out, leaving solid material behind as water scooted on ahead.

    This was in 1986-87 and he spoke about it to ASPE and others well before then. No one listened or even asked ASPE according to him, as far as he knew.

    When the "6 gallon flush" became obsolete and it dropped from that to 1.6 GPM, the first generation of such water closets were gainful employment for the Roto-Rooter type companies. Compensation was made in the form of air cushion discharges and other means of cheating gravity.

    But the point remains, a drop in flow runs the risk of leaving things behind. But for diversity of flow in downstream lines, problems would be far worse, Joe said then. The worst cases would be isolated water closets at the ends of longer runs; only one source of water input. Even if subsequent flushes cleared things, it could not possibly be a healthy situation.

    I do not think vertical lines are an issue unless I am not grasping your point on that.
  • brucewo1b
    brucewo1b Member Posts: 638
    I would think

    that what happens at the bottom end of a vertical line would be where the issue would be collecting. I never worked on house plumbing but when installing a drop you did it in a manhole in the street you always tried to make the drop in the stream so that the fluid would carry the solids that dropped if you put in 90 degree bends things drop and catch in the outside corner and will plug up.
  • Constantin
    Constantin Member Posts: 3,796
    Perhaps there are a number of variables at work?

    I agree that the older 6GPM flush systems likely had a much higher 'tolerance' band built in for flushing solids out of the system. However, some downstream characteristics have also changed, hopefully making the whole system less prone to clogging in the first place.

    Specifically, I am thinking of the green (PVC?) sanitation pipes we put in when the house was renovated. With the possible exception of copper, such plastic pipes have a lower coefficient of friction for the stuff traveling in them than their cast iron, clay, etc. bretheren and hence be able to carry more solids for a given amount of water (if pitched correctly).

    If reamed, glued, and installed correctly, plastic pipes should not ever suffer from tree root intrusion, frost heave, etc. to cause the joints to open up and for bad things to get into the pipe. The old external cast-iron pipes here had a annual appointment with the roto-rooter guys, even with 6GPF toilets because of the trees around the house. Now we have 1.6GPF toilets and not a clog yet (knock on wood).

    The logical conclusion might be that putting 1.6GPF toilets into an older home may be riskier than putting them into newer homes with plastic or copper DVW pipe that has the right pitch (settlement may be an issue in older homes, pulling the pipes out of alignement). We had an external wall 5" out of plumb here, and even an inch or two may be the difference between a "horizontal run" that can run dry or a run where water and solids can stagnate.

    Another factor that others have alluded to is how often a stack is being used. I imagine that stacks in constant use will be less prone to clogging than those where the poop can dry out and get really sticky.
  • smaller pipe works better

    3" pvc pipe will works better than the 4" pipe...side wall dia. are smaller and more water in same area will carry the soilds better and further with little pitch on pipe. Still baffled the hell out of me why those backassward plumbing codes required 4 " pipe underground , short run to sewage ejector pit while above have 2 toliets connected to one 3" pipe...
  • another things...

    In older towns with cast iron, clay pipes sewer, bringing in Lake Michiagn water to western surburbans towns of Chicago is responilble for the majority of the sewer blockages....
  • Things that I have seen...

    During a previous life, when I was still plumbing, we had to replace all of the horizontal drain lines in a building that was 5 stories tall. It was an apartment house for single abused mothers and their children. Due to a previous maintenance mans love for things acidic (drain cleaners) the horizontal mains were in dire need of replacement. They were installed in the ceiling of the main floor which was the day care facilites. Not a good place to have leaking sewer lines. The vertical stacks were connected to the horizontal drains via a wye and 1/8th bend on its back. Perfect flow directing fitting you would think...

    In every case, there was a significant buildup of solids in the horizontal drains directly below the wye in the horizontal drains. Enough to actually eventually cause a blockage in the horizontal drains. Enough so to the point that we brought it to the attention of the code authorities who said that they might consider changes in the plumbing code requiring a long sweep radiaus 90 to make the direction change from vertical to horizontal before allowing it to go into a combination fitting.

    I left the plumbing industry for things hydronic shortly thereafter, so I don't know if it ever got implemented, but it just goes to show you, that what happens in your minds eye is not always how it works in real life...

  • Darrell
    Darrell Member Posts: 303

    I just pulled and replaced a toilet in a third floor master bath...wouldn't flush worth a toot. When I pulled it...literally...I found the entire trap way below the waterline to be completely grown shut with a bateria colony...looked like something from a cheap horror film. It had actually rooted into the exposed rough china. The vertical drop below the flange was three inch ABS and was nearly completely blocked by the extended growth as well as far as I could see. Very creepy! It was a fibrous gelatinous mass that was clearly alive of its own accord. I have to wonder what the rest of the drainage looks like. A septic contractor said that they see this in the leech fields sometimes and kill it with peroxide.
  • Brad White_156
    Brad White_156 Member Posts: 11

    This certainly makes the case for fully glazed trapways. I am not sure if NSF even allows unglazed trapways...

  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    GrandPAH's Out-house

    I'm enclosing the reference list from the case study (I can't find)of the Effects Of Drain Pipe Diameter and Pitch on Low-Flush Fixtures.
    If you can't find the info your looking for here within the references I'm enclosing, you may want to actually leave "Skeeterville" and venture east. If you do decide to come, let me know and I'll let ya buy me a beer before I provide to you the "safe passage" directions to Hoboken, and Stevens Institute.

    1) Swaffield, J.A., and R.H.M. Wakelin, "Observations and Analysis of the Parameters Affecting the Transport of Solids in Building Drainage Systems" Journal of IPHE, London, 1977
    2) Swaffield, J.A., "Application of the Method of Characteristics To Model Transport of Discrete Solids in Partially Filled Pipe Flow," NBS BSS 139, February 1982.

    3) Swaffield, J.A., S. Bridge, and L.S. Galowin, "Mathematical Modeling of Time Dependent Wave Attenuation and Discrete Solid Body Transport in Gravity Driven Partially Filled Pipe Flows" Finite Elements in Water Resources Proceedings, 4th International Conference, Hanover, Germany, 1982.

    4) Galowin, L.S., "A Model for the Transport Mechanisms of Solids in Building Pipe Drains" Proceedings of National Water Conservation Conference, NSB Spec. Publ. 624, pp. 293-326, 1982.

    5) Swaffield, J.A., and L.S. Galowin " A Preliminary Study of the Vertical Stack to Horizontal Drain Entry Condition as an Extention to the Modeling of Unsteady Partially Filled Pipe Flow," NBSIR 85-3108, February 1985.

    6) Swaffield, J.A., and L.S. Galowin, "Reduced Flow Plumbing Testing and Standards," Heating/Piping/Air Conditioning, May 1991.

    7) Hunter, Roy B., " Plumbing Manual," NBS Report BMS 66, Washington, D.C., November 1940.

    8) "Necessity To Reexamine and Revise Supporting Code Issues Relative to Recent Water Conservation Codification on Required Use of 1.6 Gallon per Flush Water Closet," ASPE Position Paper, P.L. French President, and B.J. McCarty, vice president of legislation, Westlake Calif., July 19 1988.

    ***** (THIS WAS THE ONE I'M STILL SEARCHING FOR) #9) "ASPERF Ultra Low Flush Plumbing Fixute Study, A Compendium of Water Closet Performance," Stevens Institute of Technology Report No. 202, Hoboken, N.J., August 1990 (prepared for American Society of Plumbing Engineers).

    10) Malmqvist, P.O., and Olsson, "Transportation Ability Necessary Flow in a Local Network," CIB W62 Seminar, Gavle, Sweden, September 1989

    Robert O'Connor/NJ
  • Christian Egli_2
    Christian Egli_2 Member Posts: 812
    I'll just get in line to follow this topic, it's fascinating

    It sounds like someone tried Darrel's toilet to flush away the man eating Blanc-Mange from the Monty-Python horror scenes. From now on, going behind a tree in the backyard seems clearly safer.

    For the tourist in all of us, Europeans do not know what a toilet plunger is, seriously, their toilets do not ever plug. Having some come over, always warrants a little private side chat about the peculiarities of our commodes. The slow whirlpool action alone will rank high atop their travel souvenirs.

    I believe Europeans use much larger pipes in all instances, in the home alone already, one bowl will be connected to a 4 to 4.7 inch pipe. And the flushing experience is something else, it all happens in a snap, bidding farewell to your "charge" (what a beautiful euphemism, Brad) in one big wave. They've also seemed to latch on the low flow movement, long ago already with interruptible flushes, and none of this seems to have given them any hardships. I don't understand.

    On the other hand, their plastic flush tanks sweat, the mechanism inside are monsters of complication that often leak uncontrollably and for the most, the effective and energy efficient Sloan type flush valves we love so much cannot be found over there, even urinals are more often fitted with tanks.

    Next, piping wise, homes in Europe are often piped without any stack vent at all. Most new construction will have one vent to the roof, but never the double piping we torture ourselves with attempting to vent from each and every miserly sink trap. From raw footage I've seen of sewer pipe, ours are much cleaner, they dry up and breathe thanks to the phenomenal venting, theirs remain dark and dingy, they also smell... so you immediately know when the sink trap gets suctioned dry as you flush the toilet...

    So, my ideal setup would have a flush valve, a piston one like the Naval, next, I prefer our low set bowl height but I would scrap the whirlpool in favor of a European like cascading effect. Pipe wise, I would have to believe larger pipes are better and necessary with the cascading flush effect. And while I don't know what slopes are called for in Europe, I know the ventless layouts need to be improved.

    Other parts of the world have all sorts of other pooping issues.

    Where else can we talk about this stuff? Thanks Heating Help, but WOW, Robert what fine reading material you've come up with.
  • Plumdog_2
    Plumdog_2 Member Posts: 873
    Interesting Reading

    My children still hate me because I made them read from the Codebook after school, then watch the sewercam video.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Such abusive treatment, Plumdog

    leads a child to get their name in the papers years hence, carefully crafted with first, middle and last names fully spelled out....
This discussion has been closed.