4 ms·

I'm a professional engineer with experience on these types of projects. CIPP has been used since the 80s, in the US as well as Europe (and I presume Asia and O

I'm a professional engineer with experience on these types of projects. CIPP has been used since the 80s, in the US as well as Europe (and I presume Asia and Oceania). Originally it was done with hot water, though steam curing processes have an economic advantage today. UV curing processes are now wide spread as well. In the steam curing process high temperature water is circulated through the pipe to cause the resin compound to catalyze (industry term is "kick"). Steam is not allowed to escape from the liner into any sewer laterals. In fact, sewer laterals are plugged by the liner and have to be reinstated (cut out) by a robot afterwards. At the end of the process the steam is released to atmosphere, it tends to have an odor. From my understanding the odor is styrene, a common industrial solvent. Sometimes people with flaws in their plumbing report the odor is coming from the drain. This indicates they could potentially have a more serious issue: chronic exposure to sewer gases. I always recommend they have a plumber investigate. Other times the airborne plume is enough to cause very sensitive individuals to complain. There are many industry veterans who have been working with these materials for decades - if you were serious about studying the potential for harm, you would follow this group. They are the canary in the coal mine. Folks with only transient exposures are at very low likelihood of harm. The American Society of Civil Engineers gave the sewer systems in this country a grade of D+. Just above failing. In reality, and I see this every day, our sewer systems are in need of immediate overhaul. CIPP is a keystone technology for renewal of these assets, because excavation is too dangerous(!) and expensive to be our primary mode of repair. FYI - pipeline characterization and renewal is a growth industry with a lot of opportunity for AI. In my opinion, a lot of these processes could be automated. Video below shows the CIPP process. https://www.youtube.com/watch?v=Swp81X4jSDk https://www.youtube.com/watch?v=Swp81X4jSDk

abduhl 7y ago
I don’t disagree with any of the substance of what you said (as someone who has also had tangential experience in sewer rehab work), but it’s worth pointing out that ASCE has a vested interest in constantly throwing out the “nearly failing” grades. I have never taken those reports seriously (even as a card carrying member) and I suggest nobody else do it either.
flashman 7y ago
> Steam is not allowed to escape from the liner into any sewer laterals. In fact, sewer laterals are plugged by the liner and have to be reinstated (cut out) by a robot afterwards. Is there resin on the side of the liner that's plugging the lateral? In other words, you may still get odors if the thing that's doing the plugging is releasing chemicals on its exterior.
- abduhl 7y ago
  The whole liner is resin. It is produced in a factory per job (“wetted out”) and then brought to a job on a refrigerated truck then pulled into place and cured via steam/water/UV. They’re cured from the inside out but the whole thing is “resin”. The more important point though is that any odor that is coming in from the line is indicative of a problem with the lateral connection - if odor is bleeding off from the CIPP install then there is every indication that sewer gases are also making their way in. There is no positive air pressure exerted by the install on the lateral due to the curing process. Edit - just to clarify, the point is that you shouldn’t be smelling ANYTHING if the connection is in proper order - odor from the CIPP install or from sewage. If you smell one but not the other then it most likely is NOT the connection because there is no (substantial) difference in the driving air pressures between normal operation and during CIPP installation (because the CIPP seals across the lateral, preventing pressure in the lateral). If you smell the chemicals during install then it is imperative you get your line checked because you are most likely (~100%) also breathing in noxious fumes from sewage and you are so accustomed to it that you no longer notice it.
  - jessaustin 7y ago
    ...you are most likely (~100%) also breathing in noxious fumes from sewage and you are so accustomed to it that you no longer notice it. Is this a thing that is possible for humans? I shudder to imagine this, so much exposure to sewage that one ceases to notice its odor.
    - abduhl 7y ago
      You can get used to any smell given a long enough exposure. Ever been to someone's house that just reeks of dog or cat? Beyond that, it can happen in an acute sense as well. Hydrogen sulfide becomes undetectable above a certain exposure. You will usually pass out shortly afterwards (and then die because hydrogen sulfide is heavier than air and you are now on the floor). The standard advice given for people who enter confined spaces is that if you smell hydrogen sulfide (rotten eggs) you should be aware and check your sniffer. If you are still in the confined space and you suddenly stop smelling rotten eggs, you are literally seconds away from dying and should retreat to fresh air immediately or deploy SCBA.
source99 7y ago
My company- www.sewerai.com

abduhl 7y ago

I don’t disagree with any of the substance of what you said (as someone who has also had tangential experience in sewer rehab work), but it’s worth pointing out that ASCE has a vested interest in constantly throwing out the “nearly failing” grades. I have never taken those reports seriously (even as a card carrying member) and I suggest nobody else do it either.

flashman 7y ago

> Steam is not allowed to escape from the liner into any sewer laterals. In fact, sewer laterals are plugged by the liner and have to be reinstated (cut out) by a robot afterwards. Is there resin on the side of the liner that's plugging the lateral? In other words, you may still get odors if the thing that's doing the plugging is releasing chemicals on its exterior.

abduhl 7y ago
The whole liner is resin. It is produced in a factory per job (“wetted out”) and then brought to a job on a refrigerated truck then pulled into place and cured via steam/water/UV. They’re cured from the inside out but the whole thing is “resin”. The more important point though is that any odor that is coming in from the line is indicative of a problem with the lateral connection - if odor is bleeding off from the CIPP install then there is every indication that sewer gases are also making their way in. There is no positive air pressure exerted by the install on the lateral due to the curing process. Edit - just to clarify, the point is that you shouldn’t be smelling ANYTHING if the connection is in proper order - odor from the CIPP install or from sewage. If you smell one but not the other then it most likely is NOT the connection because there is no (substantial) difference in the driving air pressures between normal operation and during CIPP installation (because the CIPP seals across the lateral, preventing pressure in the lateral). If you smell the chemicals during install then it is imperative you get your line checked because you are most likely (~100%) also breathing in noxious fumes from sewage and you are so accustomed to it that you no longer notice it.
- jessaustin 7y ago
  ...you are most likely (~100%) also breathing in noxious fumes from sewage and you are so accustomed to it that you no longer notice it. Is this a thing that is possible for humans? I shudder to imagine this, so much exposure to sewage that one ceases to notice its odor.
  - abduhl 7y ago
    You can get used to any smell given a long enough exposure. Ever been to someone's house that just reeks of dog or cat? Beyond that, it can happen in an acute sense as well. Hydrogen sulfide becomes undetectable above a certain exposure. You will usually pass out shortly afterwards (and then die because hydrogen sulfide is heavier than air and you are now on the floor). The standard advice given for people who enter confined spaces is that if you smell hydrogen sulfide (rotten eggs) you should be aware and check your sniffer. If you are still in the confined space and you suddenly stop smelling rotten eggs, you are literally seconds away from dying and should retreat to fresh air immediately or deploy SCBA.

source99 7y ago

My company- www.sewerai.com