Boiling water in ABS pipe - kitchen sink

[HighqualityPlumbing]

Will a pot of boiling water poured down a kitchen sink melt ABS pipe starting ca. 2 feet downstream (after garbage disposal and under-sink piping which I couldn't care less about as it's easily replaceable)? I know the max operating temp of ABS is 180 deg F which is below the temp of boiling water, but I heard conflicting opinions on whether this is a problem when water flushes down the pipe. I'm looking for substantiated real-world experiences. Will the surface of the ABS be damaged, and will the damage accumulate over time? How susceptible is foam core ABS pipe to hot water?

 

[Terry]

I think you can get away with it, but I think it's not going to help much. For the grease to move out of there, it has to have somewhere to go.
You loosen it at the beginning, and then it sludges toward the blockage and sticks there. One one home, we went in and cut out grease filled lines.
It would have been easier to use the Bio-Clean for a week at night. My kitchen line is a long way and in the slab for a good sized run. I would rather have the grease make it's way down the natural way without running a snake down it.

 

[Sponsor]

 

[HighqualityPlumbing]

Thanks. My question was not so much for the cleaning effect of the hot water, which could be easily remedied by using 180 deg F water, but rather if tenants or family should be instructed to avoid pouring down a big pot of boiling water after cooking pasta or potatoes. I'm particularly curious about the effect on foam core ABS pipe.

 

[WorthFlorida]

A little trick I learned form my mom. She always ran cold water before dumping the boiled water through a colander. It also prevents sock to the sink material. I did have one builders grade ss sink and it would alway pop dumping a pot of boiling water into it. However, if it is an approved product and pass code inspection, apparently, it is not a problem in the other million homes.

 

[Reach4]

http://www.insinkerator.com/en-us/H...e-Disposers/Pages/Disposer-Dos-and-Donts.aspx has some suggestions.

 

[HighqualityPlumbing]

A little trick I learned form my mom. She always ran cold water before dumping the boiled water through a colander. It also prevents sock to the sink material. I did have one builders grade ss sink and it would alway pop dumping a pot of boiling water into it. However, if it is an approved product and pass code inspection, apparently, it is not a problem in the other million homes.

Thanks for your response. "Apparently is not a problem..." is not a good argument, though. With many of today's building materials, building component could have a design life of hundreds of years, if installed with the appropriate quality of workmanship and used correctly; and yet, some plumbers keep very busy cleaning out and repairing pipes.

Foam core ABS has a microscopically thin ABS layer on each side, with foam in between that is not waterproof. The thought of running water at ca. 212 deg F down a pipe whose wall has a razor thin layer of ABS with a max operating temperature of 180 deg F and subject to melting at higher temps, is scary to me at least. I'm not a plumber, but if nobody knows the answer, I will eventually try on a scrap piece myself.

 

[Standardairconditioner]

The thought of running water at ca. 212 deg F down a pipe whose wall has a razor thin layer of ABS with a max operating temperature of 180 deg F

There is transition time for heat from a boiling pasta pot to make it into the pipes.

The heat transfer coefficient of the pipes will absorb heat from the water. It does act as a heatsink.

The pipes start off at room temperature, then begin to take heat away from water immediately.

By the time the pipes get lukewarm, about half the heat from the water is gone. The pipes can never go above the 180F you fear, unless you were a manufacturing plant that was dumping hundreds of gallons of 212F water into the drain continuously. The most a typical home will throw into their sinks is a 10 gallon pot, less if it is filled with corn or lobsters.

I will eventually try on a scrap piece myself.

You can verify this experiment by dumping 212F water into your sink, get a thermo gun and read the temp of your pipes under in the cabinet.

Just don't cut a small piece of ABS and throw it into a pot of boiling water. This would be an UNREALISTIC test as the little piece of pipe will be too small to act as a heat sink of any kind.

 

[HighqualityPlumbing]

There is transition time for heat from a boiling pasta pot to make it into the pipes.

The heat transfer coefficient of the pipes will absorb heat from the water. It does act as a heatsink.

The pipes start off at room temperature, then begin to take heat away from water immediately.

By the time the pipes get lukewarm, about half the heat from the water is gone. The pipes can never go above the 180F you fear, unless you were a manufacturing plant that was dumping hundreds of gallons of 212F water into the drain continuously. The most a typical home will throw into their sinks is a 10 gallon pot, less if it is filled with corn or lobsters.


You can verify this experiment by dumping 212F water into your sink, get a thermo gun and read the temp of your pipes under in the cabinet.

Just don't cut a small piece of ABS and throw it into a pot of boiling water. This would be an UNREALISTIC test as the little piece of pipe will be too small to act as a heat sink of any kind.

Point well taken, although I'm still not convinced that the short section of 1.25" thick plastic pipe under the sink will absorb or transfer enough heat to measurably lower the temperature of 1-2 gallons of boiling water poured down. Plastic is a very good insulator and has little heat capacity. For comparison purpose, a typical 30 foot section of 1/2" copper pipe between the water heater and shower only lowers the temperature by a few degrees. (Copper pipes are usually not insulated in California.) But that is copper vs. plastic, and 30 ft vs. 2 ft., and 1/2" vs. 1.25"... I'm not convinced, and I think pouring leftover water from the stove down the sink may result in property damage in houses with foam core ABS pipes, until I verified the contrary. I'm curious how the thin ABS layer on foam core ABS behaves when in contact with water near the temperature of boiling water.

 

[Reach4]

I'm not convinced, and I think pouring leftover water from the stove down the sink may result in property damage in houses with foam core ABS pipes, until I verified the contrary.

I am thinking that the transit through the pipes would not be the problem, because things are moving along.

If you are to test, how about pouring your boiling water into a P-trap? Then the water is retained.

 

[HighqualityPlumbing]

I am thinking that the transit through the pipes would not be the problem, because things are moving along.

If you are to test, how about pouring your boiling water into a P-trap? Then the water is retained.

Thanks, but based on the principles of thermodynamics, I don't think it matters for the purpose of this discussion whether the water is moving or not pe se, other than maybe the length of time that the water is in contact with the ABS. I estimate that when pouring down 1 gallon, the hot water will be in contact with the ABS pipe at a particular point close to its entry into the wall/foundation for about 20-30 seconds at probably close to the temperature of boiling water on the inner surface of the pipe. Given the thin layer of ABS on foam core ABS of probably less than a millimeter, my concern is not relieved at all. I will test myself if I have to and if we don't get a substantiated answer on this forum for this (in my opinion) important question.

 

[Reach4]

In trying to find references, I did not find things as clear as I would have liked. Here are three links:

I don't know what the pipe abbreviations are, but this one gives values based on tests...
http://www.pvc.org/en/p/heat-distortion-temperature-softening-temperature

The rated operating temperatures I think will have some safety factor built in:
http://www.engineeringtoolbox.com/plastic-pipes-operating-pressure-d_1621.html

Also see page 42 of http://www.charlottepipe.com/Documents/PL_Tech_Man/Charlotte_Plastics_Tech_Manual.pdf

 

[HighqualityPlumbing]

In trying to find references, I did not find things as clear as I would have liked. Here are three links:

I don't know what the pipe abbreviations are, but this one gives values based on tests...
http://www.pvc.org/en/p/heat-distortion-temperature-softening-temperature

The rated operating temperatures I think will have some safety factor built in:
http://www.engineeringtoolbox.com/plastic-pipes-operating-pressure-d_1621.html

Also see page 42 of http://www.charlottepipe.com/Documents/PL_Tech_Man/Charlotte_Plastics_Tech_Manual.pdf

Thanks. I found the information in your first link interesting. According to it, ABS would at least fare better than PVC in both scenarios. (I think in some states other than California PVC is used for drain pipes, so they would have a similar concern.) PVC however is only solid core as far as I know, which is probably a whole lot more robust to damage from temporary and localized overheating. The test scenarios in the article use deflection and a vertical needle, respectively. As neither of the two test scenarios in the article apply directly to the scenario of potential damage of the thin ABS layer on foam core ABS in contact with hot water, further research or testing is warranted.

 

[Reach4]

I found the information in your first link interesting. According to it, ABS would at least fare better than PVC in both scenarios.

That was a bit of a surprise to me.

PVC however is only solid core as far as I know, which is probably a whole lot more robust to damage from temporary and localized overheating.

DVW PVC is also made in foam core. Here is an old thread discussing it: https://terrylove.com/forums/index.php?threads/schedule-40-pvc-vs-schedule-40-foam-core.20040/

 

[Jadnashua]

Foam core is cheaper, so will likely always be available, but would be my second choice over solid stuff.

 

[Cacher_Chick]

We don't see ABS DVW piping here in the Midwest. During the past few years, most plumbing suppliers discontinued stocking solid core PVC in the larger sizes. 2" is always available in either/or because the solid core is required in HVAC.

The problem in testing at home is that you are not likely to be able to conduct a meaningful test. As an example, consider for instance that your test pipe may look and work fine after hundreds of gallons of boiling water is poured through it, but it may have changed on a molecular level, with symptoms like increased hardness an/or reduced tensile strength. This is just one of many possibilities that could very well take place, but who is to say what is "acceptable" or "not acceptable"?

 

[HighqualityPlumbing]

We don't see ABS DVW piping here in the Midwest. During the past few years, most plumbing suppliers discontinued stocking solid core PVC in the larger sizes. 2" is always available in either/or because the solid core is required in HVAC.

The problem in testing at home is that you are not likely to be able to conduct a meaningful test. As an example, consider for instance that your test pipe may look and work fine after hundreds of gallons of boiling water is poured through it, but it may have changed on a molecular level, with symptoms like increased hardness an/or reduced tensile strength. This is just one of many possibilities that could very well take place, but who is to say what is "acceptable" or "not acceptable"?

I completely agree. I think there should be an engineering study and document regarding this scenario somewhere. Otherwise, a test at home may only give an indication on how the material behaves, which is better than nothing though.

 

[Standardairconditioner]

Ok look, the manufacturers test stuff like this, and it's not like abs was invented yesterday like pex. But I do know when they invented pex, they did all sorts of pressurized test, hard water test, etc.

Where is this discussion going? Are you going to run for senate and make some changes to the abs industry? Are you building your own dream home and would like to refit with 100% copper drains? Basically we don't NEED to prove abs works. You may want to contact every abs manufacturer out there. You are the one that needs to prove that abs FAILS. And with real world realistic data, so you can forget about cutting a snippet of pipe and boiling that in a croc pot for 4 hours. There isn't some conspiracy going on since the 1970's putting abs into homes.

This was actually on my mind today. I found corn cobs on sale today at the supermarket and boiled them all in my pot. Dumped it all into my kitchen sink as usual. Wow my abs pipes did not explode. And I have done this thing before too during the last 10 yrs I have lived in this house. And so did the previous homeowners with the abs drains that were put in about 20 yrs ago.

 

[Jadnashua]

FWIW, if I remember, the first pex was used in Europe over 30-years ago...it's just that it took forever for it to show up on this continent.

 

[HighqualityPlumbing]

Ok look, the manufacturers test stuff like this, and it's not like abs was invented yesterday like pex. But I do know when they invented pex, they did all sorts of pressurized test, hard water test, etc.

Where is this discussion going? Are you going to run for senate and make some changes to the abs industry? Are you building your own dream home and would like to refit with 100% copper drains? Basically we don't NEED to prove abs works. You may want to contact every abs manufacturer out there. You are the one that needs to prove that abs FAILS. And with real world realistic data, so you can forget about cutting a snippet of pipe and boiling that in a croc pot for 4 hours. There isn't some conspiracy going on since the 1970's putting abs into homes.

Even standard building materials can fail all the time for various reasons depending on the environment and numerous parameters. "Everyone does it" does not mean much, because every situation is different, and every building material has pros and cons. The manufacturers did perform tests and determined limits, some of which are pushlished in the references mentioned further up in this thread, which lead to the question posted in this thread. It appears that this thread gathered some interest, as I can tell from some other posts in this thread, some of which were really helpful. On another note, I know of numerous homeowners who are unsure about this same issue; some of them avoid pouring hot water down while others don't, without knowing whether there may be damage in the long run. If you are either not interested in the subject, or have nothing to contribute, or both (as it seems), what prompts you wasting your time making some contemptuous and cynical comments, just to make others feel miserable? If you are feeling frustrated today, why aren't you silent?

 

[Cacher_Chick]

I don't worry about such things, and encourage others to test things to their heart's desire.

When you consider the history of piping failures such as polybutane, kitec, orangeburg, etc., there have been plenty of products that did not perform over time. I don't have faith in anything that hasn't been proven over many years.
We learn a lot through the experience of others, which is why forums like this one are so great.