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Post by the light works on Dec 14, 2016 14:44:38 GMT
I am thinking more on the toilet problem of say 30ft of water has a lot of pressure, if that was 300ft of water, all at the same time, on the sewer pipes, could the lower sections of pipe hold that much pressure?.. If a 300ft vertical pipe was filled to the top with water, the pressure at the bottom would be about 150psi. I would think the problem would be dropping a slug of water 300 feet and what happens when it hits the bottom. More of a water hammer problem than a pressure problem. I don't have a plumbing codebook, but I would be inclined to guess there are probably minimum pressure ratings for drains in high rise buildings. and without a clog capable of withstanding the pressure, how high a water column could you develop just by flushing a toilet. I know that our 5" fire hose holds about a gallon per foot. not sure how big the drain lines in a high rise are, but they have to size them to accommodate the anticipated flow. |
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Post by silverdragon on Dec 14, 2016 16:01:12 GMT
Thanks for the info, and yes, I was thinking about sudden jumps in pressure.
I am sure that the plastic pust-to-fit junk is far from what they would use.... :eek
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Post by GTCGreg on Dec 14, 2016 17:06:27 GMT
Thanks for the info, and yes, I was thinking about sudden jumps in pressure. I am sure that the plastic pust-to-fit junk is far from what they would use.... :eek I had that problem and it was only with a 2 story house. The drain pipe that came down from the second floor bathrooms was a 4" pvc. At the bottom was a pvc elbow that was just glued in place. After many years of abuse, the glue gave out and the elbow separated from the drop pipe. The only way I found out something was wrong was by a bad smell that started emanating from the crawl space. By the time I went in to check, I had quite the mess to clean up. After I glued the pipe back together, I secured it with a pipe strap so the stress was no longer on the glued part. It's been holding for 5+ years now but I still occasionally check it. |
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Post by silverdragon on Dec 15, 2016 6:01:48 GMT
Thanks for the info, and yes, I was thinking about sudden jumps in pressure. I am sure that the plastic pust-to-fit junk is far from what they would use.... :eek I had that problem and it was only with a 2 story house. The drain pipe that came down from the second floor bathrooms was a 4" pvc. At the bottom was a pvc elbow that was just glued in place. After many years of abuse, the glue gave out and the elbow separated from the drop pipe. The only way I found out something was wrong was by a bad smell that started emanating from the crawl space. By the time I went in to check, I had quite the mess to clean up. After I glued the pipe back together, I secured it with a pipe strap so the stress was no longer on the glued part. It's been holding for 5+ years now but I still occasionally check it. Most of this house is "Push to fit", but its all with rubber "O" ring holding it snugly in place. No crawl spaces. Straight out the wall and into the drains... Except the 4inch sewer stack, that is all concreted in place, and firmly screwed to the wall. |
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Post by GTCGreg on Dec 15, 2016 13:41:31 GMT
That's the type of connection I have where the PVC pipe connects to the cast iron pipe that goes out to the street. Everything else within the house is all glued PVC connections. I've had problems with those connections in a couple of places. I think they just weren't glued properly, or the wrong type of glue was used when they were originally put together.
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Post by the light works on Dec 15, 2016 14:45:00 GMT
That's the type of connection I have where the PVC pipe connects to the cast iron pipe that goes out to the street. Everything else within the house is all glued PVC connections. I've had problems with those connections in a couple of places. I think they just weren't glued properly, or the wrong type of glue was used when they were originally put together. I agree with the improper gluing. a properly glued PVC or ABS pipe connection is a chemical weld, and the pipe will break rather than the glue joint. |
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Post by GTCGreg on Dec 15, 2016 14:50:12 GMT
That's the type of connection I have where the PVC pipe connects to the cast iron pipe that goes out to the street. Everything else within the house is all glued PVC connections. I've had problems with those connections in a couple of places. I think they just weren't glued properly, or the wrong type of glue was used when they were originally put together. I agree with the improper gluing. a properly glued PVC or ABS pipe connection is a chemical weld, and the pipe will break rather than the glue joint. Right. And where I've had failures, there was no sign of "welding." I think the only thing holding the pipes together was the cohesiveness of the glue. |
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Post by the light works on Dec 15, 2016 14:58:33 GMT
I agree with the improper gluing. a properly glued PVC or ABS pipe connection is a chemical weld, and the pipe will break rather than the glue joint. Right. And where I've had failures, there was no sign of "welding." I think the only thing holding the pipes together was the cohesiveness of the glue. I have times I want to leave a provision to break the joint if I need to, and other times I want to do so easily, but the official word I have been told for "properly glued" is that the glue will smear the printing on the pipe if you've applied it properly. I've had a couple repair jobs I've been called on where the trench has settled and pulled the pipe out of the fitting at the meter. fortunately, they make repair couplings that work great for that. |
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Post by silverdragon on Dec 16, 2016 5:36:27 GMT
The "proper" glue for PVC pipes is the same stuff you get in Airfix Model kits, its a "Poly" glue, and as stated, it partially melts the pipe to make a weld stronger than pipe, because as you are glueing two sections together, that makes it double thick at the weld.
If it comes apart, therefore, you used the wrong glue.
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Post by the light works on Dec 16, 2016 5:44:50 GMT
The "proper" glue for PVC pipes is the same stuff you get in Airfix Model kits, its a "Poly" glue, and as stated, it partially melts the pipe to make a weld stronger than pipe, because as you are glueing two sections together, that makes it double thick at the weld. If it comes apart, therefore, you used the wrong glue. and if you are using it in a confined space, you really want good ventilation. funny, when I was a kid, and they told us we shouldn't sniff glue, I only knew about Elmer's. |
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