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can i use threaded pvc rather than cement?

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frodo

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To answer your question,
can i use threaded pvc rather than cement?
The Answer is NO,
The CODE:

pvc_.png
The Reason why, simply put, a female adaptors threads catch hair and yuk yuk
causing clogs, because the fitting is not a true Durham fitting.

That is it, there is no damn argument on this point

 

Mr_David

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i

Please expand, when i said i needed to connect pvc to a 1.5 remail threaded hole in a iron drain i was handed a pvc adaptor, male threads one side and you cement your 1.5 pvc pipe in the other end, im sure you know the piece,

That's how I would do it. Some where I read you wanted to use 2 threaded fittings? Plastic female fittings have a greater potential for splitting when a male fitting is screwed into it. I would not normally do what is described in the following sentence .


Now if i am understanding you , you are saying dont do that it will cause problems but rather get a stub piece of "metal" pipe screw it into the iron pipe then use one of the shielded rubber couplers to connect that metal stub to the pvc,

If I had to screw a metal nipple into the iron pipe female threaded hole, I would use a brass nipple.

B
I also recommended cleaning/re-tapping the threads with a pipe tape.
 
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Mr_David

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Never thread dissimilar materials such as plastic and metal pipes together. Recipe for disaster. Always install a short ~3-4" stub out of new metal pipe nipple in a female metal fitting. Use a shielded no-hub coupling, NOT the rubber only Fernco type, SHIELDED only to connect the new pipe stub to the plastic pipe.
This can be a whole new discussion on that statement.
How can screwing a plastic fitting into and iron fitting be a recipe for disaster?
I peel out DWV copper trap arms from threaded cast iron tapped tees and replace with male threaded plastic ABS fitting all the time.
Sure beats ripping open the wall and chopping out the whole Sanitary tee.

Back in the old days even before my time It was all leaded or threaded.
 

frodo

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This can be a whole new discussion on that statement.
How can screwing a plastic fitting into and iron fitting be a recipe for disaster?
I peel out DWV copper trap arms from threaded cast iron tapped tees and replace with male threaded plastic ABS fitting all the time.
Sure beats ripping open the wall and chopping out the whole Sanitary tee.

Back in the old days even before my time It was all leaded or threaded.
true.
tapped tees are straight threads and female adapters are beveled threads
the male thread mip, when it threads into a female adaptor fip
will not go all the way in, there will be female threads visible, these threads will catch gunk
a threaded plumbing system than uses straight threads so that the inside of the pipe is smooth with out
pockets to catch stuff is called a durham system
 

jwwing

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Never thread dissimilar materials such as plastic and metal pipes together. Recipe for disaster. Always install a short ~3-4" stub out of new metal pipe nipple in a female metal fitting. Use a shielded no-hub coupling, NOT the rubber only Fernco type, SHIELDED only to connect the new pipe stub to the plastic pipe.
I am completely confused by this statement. There are a few reasons for using this type of special coupler, but the proposed usage does not suggest the need, does it? What is the basis for your statement? Brass to plastic without special coupling has been successfully used for years - is there new data? New rules?

The rule used to be dissimilar 'metals' and that was because of corrosion from ion-exchange etc., it hardly applies to plastic. And there are many cases where I have used threaded plastic rather than slip-on glued ones because they are easier to replace. I assume that you have worked in a foot square hole and find the shut off valve has failed again. I put them together with a union and threaded connections that can be reused without sawing them apart. Yes, they do fail, but they are essential to the system so I put up with them. But I don't put up with digging up two feet of pipe, cutting out a section of pvc and using a new coupler and putting it together the 'professional' way.

But the proposal here is to use plastic into the threaded metal fitting in a refurbishment of an old building. Aside from local plumbing code restrictions (which would be none in many locales), there should be no problem with using plastic directly for a drain pipe. And schedule 40 pipe should be plenty strong enough, easily available and inexpensive.

OPs statement that he has decided to go ahead with the use threaded fittings is a no-brainer. There is absolutely no difference - the pvc is designed for both and it will work well. The easiest is not always the best and the best is not always the easiest. His decision is his to make, not ours. All one can do is suggest alternatives and he gets to choose, or doesn't he? After all, he gets to do the work and he suffers the consequences - just tell him why it might not work as he expects.
 

jwwing

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So sometimes you do use threaded...

I explained why in my original post,
But to further clarify, i am trying not to tear all the floor out, sure i know that is what a "professional" would insist on doing ( partly to charge more ) but i tend to think more outside the box with stuff, and to me screwing the tub drain pipe in would be easier than trying to get it that 3 feet under the floor to the T all dripping cement making using primer then cement very hard to pull off,

Theres a lot of irony to me for it to be a big thumbs up to use a pvc threaded adaptor into the iron pipe but dont use threaded pvc to pvc
I agree with you that it is a good enough reason for you to use the threaded pipe - it is much more expensive for the larger connectors though, and even in the situation that you describe, you might be better served to pre-assemble some of it so that the application of the cement is done well. The main thing on a run of plastic is that you do not allow it to sag - it will fill in and then the pipe will slowly fill up and you have a plug.

Also, the threaded pipes do not fit together perfectly (or as perfectly) as the slip-on pipes do so they have a tendency to collect material from the drain. Regardless of what starts it, the material begins to build and continues until it closes the pipe. But I have experienced that same affect on slip-on joints especially between smaller to larger diameter pipes. When the usage is heavy with lots of particulates, the plug happens very rapidly if something disrupts the flow. I had one home where the drain from the kitchen sink ran about 20 feet and dumped into what felt like a larger pipe. For some reason, that connection plugged repeatedly at that junction. I had to run a garden hose through the vent in the roof and plug the sink drain in order to get it to flow. A snake would not work. With the garden hose, I could feel the soft clog and by putting some pressure on it, I could break through so the drain would run again. Unfortunately, I could not see how good the job was (how much gunk got by without being removed) so a year later, repeat performance. This gunk growth is a real problem sometimes and the threaded pipes could make it worse and would mean multiple clean-outs to be expected worst case.
 

jwwing

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That is it, there is no damn argument on this point
Dear frodo, the code that you listed clearly states (and you put it into large letters) 'in inaccessible locations' that means places that cannot be reached easily. The reason given is collection of gunk to shorten the argument. Your statement is correct in this case but your attitude and BS is wrong. His location is not inaccessible and what accessible is can be easily corrected by making an access panel.

Your out of line here - what is the point in doing that? He is in alignment with the code - even you can read that if you wanted to. So, yes there is argument over your interpretation of his situation. Where he wants to put the threaded stuff is accessible unless 'accessible' took on a new meaning because you say so.

Another thing, the code is written to general situations - tell us a lie and tell us that you have not run into situations where the language of the code is questionable for the situation. The place where hair and gunk builds up is not only because of threads - just the joint can do the same thing - I can give you chapter and verse on experience with perfectly formed joints that collected gunk, too. But the rule itself is a good one, but a reasonable inspector would not stop him from doing it that way if he showed him how he could access it.
 
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frodo

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I am working on a 100 plus yo upstairs bathroom,

I needed to replace the old rusty plugged up galvanized sink
Dear frodo, the code that you listed clearly states (and you put it into large letters) 'in inaccessible locations' that means places that cannot be reached easily. The reason given is collection of gunk to shorten the argument. Your statement is correct in this case but your attitude and BS is wrong. His location is not inaccessible and what accessible is can be easily corrected by making an access panel.

Your out of line here - what is the point in doing that? He is in alignment with the code - even you can read that if you wanted to. So, yes there is argument over your interpretation of his situation. Where he wants to put the threaded stuff is accessible unless 'accessible' took on a new meaning because you say so.

I do not need you to speak up for someone else, You are not a mod
Do not try and school me again with your bullshit , be gone
 

jwwing

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true.
tapped tees are straight threads and female adapters are beveled threads
the male thread mip, when it threads into a female adaptor fip
will not go all the way in, there will be female threads visible, these threads will catch gunk
a threaded plumbing system than uses straight threads so that the inside of the pipe is smooth with out
pockets to catch stuff is called a durham system
Of course, that is true, but any joint has the same possibility, including slip-on joints and even worse if the cement is not right. But I agree that the extra threads collect gunk and it builds up. This could mean that clean out has to occur more often in some cases, but that is a decision that the plumber can make, especially on his own property.

Let's encourage him to follow the code and he probably will since he is here talking about it - chase him away and all you have is someone making a mess for somebody to clean up later on all sorts of sordid ideas that he might be having.
 

jwwing

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I do not need you to speak up for someone else, You are not a mod
Do not try and school me again with your bullshit , be gone
Is this really how you feel, why didn't you say so? Was I so far wrong when I said that some of you pretend that you are gods? You want to help somebody or do you just want to drive everyone else away from a perfectly good site? There is no excuse for this kind of conduct and if you are not censured for it I will be gone. Life is to short to put up with this kind of inane BS.
 

voletl

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Is this really how you feel, why didn't you say so? Was I so far wrong when I said that some of you pretend that you are gods? You want to help somebody or do you just want to drive everyone else away from a perfectly good site? There is no excuse for this kind of conduct and if you are not censured for it I will be gone. Life is to short to put up with this kind of inane BS.
Then leave lol. Not that hard guy, if you need a safespace then go elsewhere.
 

Mr_David

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true.
tapped tees are straight threads and female adapters are beveled threads
the male thread mip, when it threads into a female adaptor fip
will not go all the way in, there will be female threads visible, these threads will catch gunk
a threaded plumbing system than uses straight threads so that the inside of the pipe is smooth with out
pockets to catch stuff is called a durham system
Those are like leaded hub & spigots joints. Nobody uses them any more.
Even now in modern install, they use a soldered on threaded ring that on 1-1/2' copper DWV trap arms.
Those are only about 3 , maybe 4 threads deep. So there is always a thread or 2 left inside the cast fitting.
 

Mr_David

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I like Frodo, Glad he's back. I missed him and like most of his input, But I'm going to take sides with jwwing.
I don't think he was out of line. I try not to correct others when they are wrong. I just move on.
I did notice that Frodo's snip of the code said female and inaccessible, and really did not apply.

Okay I'm done.

I stopped in to link a thread I did awhile back. In regards to replacing DWV trap arm in a tapped Sanitary tee.
It's kind of related

https://www.plumbingforums.com/threads/how-to-repair-dwv-copper-trap-arm.6382/
 

frodo

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The reason I quoted the code, and mentioned the fact that a shemale can not be used in an accessible space were these comments
in the original op


I am working on a 100 plus yo upstairs bathroom ,

I needed to replace the old rusty plugged up galvanized sink and tub drains
The catch i wanted to bust as little of the floor as possible ,

The rectangle room has the old but good iron main drain toilet on top at one cornor,
Then the other cornor has the sink, the tub drain was T,ed into that sink drain, it goes to the side of the iron pipe behind where the toilet sits on it,

I got all the old pipe out wasnt easy, nice threaded 1.5 hole in the iron stand pipe to connect to, wasn't easy getting that rusted galvanized threads out of there,

My original plan was to cement the pieces and pipe ( pvc ) together as i assembled worked them into their space , in the floor,
But dawned on me with it cemented together it would have to be cut to do any service and getting it all together with some connection out of reach with cement would be a bit tricky, not impossible but difficult.

So can i use pvc threaded fittings on the pvc pipe and just screw sections together, no pressure just a tub and sink drain, is pink tape what to use on the threads, or is there a sealer for this some places will still be cemented together but for example screwing the tub drain pipe into the T with make it so much easier,

If i can do it with some threads fittings it would make it easier and give me peace of mind i could service it without cutting it out,

Okay...clue me in,

Thanks
b
these words I have have underlined, tell me this work is being done in the floor and the ceiling below is not being removed, the work is not accessable
yes, access doors can be installed. but will not happen
I stand by my comments.
 
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frodo

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I like Frodo, Glad he's back. I missed him and like most of his input, But I'm going to take sides with jwwing.
I don't think he was out of line. I try not to correct others when they are wrong. I just move on.
I did notice that Frodo's snip of the code said female and inaccessible, and really did not apply.

Okay I'm done.

I stopped in to link a thread I did awhile back. In regards to replacing DWV trap arm in a tapped Sanitary tee.
It's kind of related

https://www.plumbingforums.com/threads/how-to-repair-dwv-copper-trap-arm.6382/

love ya Dave. 73c488f096fc4d4e910a5a20be8cf5e06243040b062557252608ecc6aee99033.jpg
 

SHR

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Wow, I'm not feeling the love. :grrrr:
Because "jwwing" is a collosal idiot and asked for advice but he believes he knows more than the professionals with hundreds of years of experience. I'm just glad I have not had to work on his plumbing. I would probably do something really bad...
 

justin_dewan90

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Finally thought this thread was dead. Then this. No disrespect friend, just busting your balls.
 
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