Leak behind sink, PT2

[Dave]

Was telling someone about the work we had done, where I had to cut a hole in the side of the house to give the plumber access to the pipes in question, and suddenly realized that it looked like he used plain old Sch. 40 PVC for the drain for the kitchen sink. Problem is, I think, my wife likes to pour a big stockpot (has to be four gallons, seriously) of boiling water down the sink drain first time it starts to run slow or stop up. If I am not mistaken, that will not work well with standard schedule 40 PVC, will it? I suspect I need CPVC in that drain line, do I not? Can anyone (try to) enlighten me as to what will happen if my wife pours boiling water down the drain if it is made out of standard PVC? I have a picture that shows the piping with writing on the side. It says "PVC-1120 SCH 40 RR .330 PSI @ 73 (degree mark) F" Is that not standard schedule 40 PVC? The receptionist at the plumbing co. says they "always use CPVC, so it's fine. Don't worry."

If somene will clue me in to where I might post this so others here on the NG can see what I am talking about, I will try to do that. I hate to be totally clueless, but I have no idea as to where to post such a picture so I can provide the link for others to go observe it.

Many thanks,

Dave

[trader4]

PVC used for drain pipes is normally the DWV type. However I think you will find that both it and PVC used for fresh water will be OK when used for drains which are not pressurized even if you occasionally pour boiling water down them. The pipe spec you are looking at says it will withstand 330PSI at room temperature. Given that it has almost no pressure in a drain application, I'd say you're fine.

Simple experiment. Heat up a pot of water until it's boiling. Turn off the heat. Insert a piece of PVC for a few minutes and see if it's still rigid when removed. That test is a lot worse than just pouring some boiling water down the sink. You can bend PVC by heating it, but I've always done that over a gas stove flame, which takes the pipe to a lot higher than 212F, at least I think.

[Dave]

PVC used for drain pipes is normally the DWV type. However I think you will find that both it and PVC used for fresh water will be OK when used for drains which are not pressurized even if you occasionally pour boiling water down them. The pipe spec you are looking at says it will withstand 330PSI at room temperature. Given that it has almost no pressure in a drain application, I'd say you're fine.

Simple experiment. Heat up a pot of water until it's boiling. Turn off the heat. Insert a piece of PVC for a few minutes and see if it's still rigid when removed. That test is a lot worse than just pouring some boiling water down the sink. You can bend PVC by heating it, but I've always done that over a gas stove flame, which takes the pipe to a lot higher than 212F, at least I think.

Hey Trader...

Okay, that makes some sense at least. I was checking online, and it kind of looks like CPVC is Schedule 80. Does that sound right? Just wondering, and trying to understand what I found...

Many thanks,

Dave

[bob haller]

.

the better drain pipe can be used for pressure applications DWV isnt designed for that.

and tell your wife to run cold water while duming her stock pots to cool the drain water a little

[RogerT]

If you mean how can you post a picture here, you can do this:

Go to

. Then click on "Browse" to find the picture that you want to upload. Click on that picture, the click "Upload".

After you upload it, copy the URL address that appears in the "Direct Link for Layouts" box and paste into a message that you post here. Then anyone who reads the message can click on that link and you picture will pop up.

As far as using Schedule 40 for the drain, even though your wife pours boiling hot water down the drain, I don't think that will be any problem. I am not even sure you would be able to find CPVC in 1-1/2" or 2" sizes for a drain if you wanted to use that. I've never seen it used for. And, as someone else here already posted, the writing on the side of the PVC that you have now is about what pressure it will withstand at a certain temp.

[hrhofmann]

..

she uses bioiling water to clear a slow-running drain, read the OP.