# 3/8 copper = 1/2 pex?



## orson (Nov 23, 2007)

I told the plumber on a job that I was not very happy he ran 1/2 inch PEX off 3/8 copper instead of cutting the 3/8 out and running a 1/2 inch all the way back(all the way back being another 6 inches). 

He responded that because the PEX fittings are 3/8 i.d. in the fittings it is no different than running 3/8 copper. I'm thinking he's full of pooh, but maybe I'm poohey too? 

Please clean one of us up off the sidewalk, and explanations are always appreciated!!:w00t:


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## Bill (Mar 30, 2006)

He is right. Actually if I recall the pex is 7/16" so there is no significant difference between the two.


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## Ron The Plumber (Oct 10, 2006)

What was this for? What was it going to feed?

Tell us more on the subject.


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## 22rifle (Apr 23, 2008)

orson said:


> I told the plumber on a job that I was not very happy he ran 1/2 inch PEX off 3/8 copper instead of cutting the 3/8 out and running a 1/2 inch all the way back(all the way back being another 6 inches).
> 
> He responded that because the PEX fittings are 3/8 i.d. in the fittings it is no different than running 3/8 copper. I'm thinking he's full of pooh, but maybe I'm poohey too?
> 
> Please clean one of us up off the sidewalk, and explanations are always appreciated!!:w00t:


Why didn't he cut out the 6" of 3/8"?

Are you talking 3/8" OD tubing? In plumbing lingo, 3/8" copper means 3/8" OD. In HVAC 3/8" copper means 1/2" OD.

On one hand, 6" of 3/8" OD is hardly anything to worry about. The fitting ID's are that small.

But on the other hand, just because you have a few fittings with a small ID does not mean it has the same flow rate as a pipe with the same ID. Think about it, your tub water comes through a 1/4" or less hole. And it will flow just fine if the pipe serving it is large enough. But try serving a tub with a 1/4" ID pipe and you would be screaming at the low flow.

I would need more details about where this pipe is, etc. before I could really make an informed judgment call. What does this line feed, what does it branch off of, etc. Can you fill us in on those details?

A pic would be sweet!

But I am more concerned about why he didn't just cut out the 6". Was there a valid reason? Or was it sloppiness?


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## 22rifle (Apr 23, 2008)

USP45 said:


> He is right. Actually if I recall the pex is 7/16" so there is no significant difference between the two.


Hang on...

You do realize there is a difference between a restriction at the fittings and the entire pipe being of the diameter of the fitting ID don't you?

Also, while we don't know if the pipe mentioned is 3/8" OD (plumbing) or 3/8" ID (HVAC), even if it is 3/8" ID, 7/16" ID is a far cry from 3/8" ID. Not accurate to say no significant difference there.

And we haven't even gotten into the difference in flow rates between PEX and copper.


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## orson (Nov 23, 2007)

I think it was because he would have had to do a little bit more work, but he was on T&M so it shouldn't have mattered. 

The 3/8 copper was feeding a shower in the basement and a whirlpool tub at one spot, at another it was feeding 2 sinks.


this is where it feeds the 2 sinks, the pex is feeding the upstairs sink and the 1/2inch copper is feeding the basement sink.


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## orson (Nov 23, 2007)

22rifle said:


> Hang on...
> 
> You do realize there is a difference between a restriction at the fittings and the entire pipe being of the diameter of the fitting ID don't you?
> 
> ...


That's what I need to be edumacated on, I assume there is a big difference or no one in their right mind would plumb anything in PEX, but I don't really know for sure so I didn't argue w/ the plumber.


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## orson (Nov 23, 2007)

Here's the line feeding the whirlpool. The supplies for the shower in the basement will be eliminated in the near future but I forgot to tell him that


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## Ron The Plumber (Oct 10, 2006)

I guess you will know when it gets inspected, or are you doing this without permits?


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## orson (Nov 23, 2007)

it already was inspected, it failed due to a sanitary T on it's back.

Just because the other stuff passed inspection doesn't mean it doesn't need ripped back out if it ain't right:thumbsup:


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## Ron The Plumber (Oct 10, 2006)

Did the inspector see this? If he did then don't sweat it.


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## orson (Nov 23, 2007)

I assume he saw it, he didn't comment on it. 

The inspector doesn't have to live in the house and fill that whirlpool tub, so whether he saw it or not doesn't really matter much to me.


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## Ron The Plumber (Oct 10, 2006)

He would have noted it if he felt there was a problem with it, if you feel it's not right contact the inspector and ask him, who knows, he could have overlooked it, can't argue with him, well you can, but you won't win 98% of the time.

If it was me I would have removed the 3/8 but that's me.


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## Ishmael (Mar 14, 2007)

orson said:


> I think it was because he would have had to do a little bit more work, but he was on T&M so it shouldn't have mattered.
> 
> The 3/8 copper was feeding a shower in the basement and a whirlpool tub at one spot, at another it was feeding 2 sinks.
> 
> ...


And why didn't he fix that leaky solder joint on that tee while he was at it? :no:


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## 22rifle (Apr 23, 2008)

Ron The Plumber said:


> Did the inspector see this? If he did then don't sweat it.


What difference does it make whether the inspector saw it or not? Trying to understand what you are saying.


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## Ron The Plumber (Oct 10, 2006)

If he saw it then maybe it meets code, I don't know the codes in PA but here min size is 1/2" to any said fixture. It would not fly by an inspector here. Orson needs to contact the inspector on this, cause the plumber is not going to change it just cause Orson wants it changed, it will take the Administration Authority to make the call. In IMO it's not code but I could be wrong.

But yea looks like a lazy plumber to me, any real plumber would have fixed the corroded pipe shown in the picture, Orson should be more concerned about that then anything else, HO should be told about the problem that could result in water damage down the road.


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## 22rifle (Apr 23, 2008)

orson said:


> it already was inspected, it failed due to a sanitary T on it's back.
> 
> Just because the other stuff passed inspection doesn't mean it doesn't need ripped back out if it ain't right:thumbsup:


cough, cough

What kind of "plumber" is this guy? A san-T on it's back?

I already have a pretty negative opinion of the crappy job I am seeing in the pictures. This doesn't help.

Honestly, I am a poor source of advice for you on this one. I have zero tolerance for the kind of work I am seeing in the pics. Because of that, what I tell you, and what is acceptable to many people, is two different things. I am just too hard nosed about doing a good job to be fair about this all. I am the kind of guy who says "Do it right, or go flip burgers." 

But for me to sit here and tell you what you need to do about this is not right. I can tell you what I would do. But like I said, I am anal about this kind of stuff.


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## 22rifle (Apr 23, 2008)

Ron The Plumber said:


> If he saw it then maybe it meets code, I don't know the codes in PA but here min size is 1/2" to any said fixture. It would not fly by an inspector here. Orson needs to contact the inspector on this, cause the plumber is not going to change it just cause Orson wants it changed, it will take the Administration Authority to make the call. In IMO it's not code but I could be wrong.
> 
> But yea looks like a lazy plumber to me, any real plumber would have fixed the corroded pipe shown in the picture, Orson should be more concerned about that then anything else, HO should be told about the problem that could result in water damage down the road.


OK. So basically the reason you are bringing in whether the inspector saw it or not is because it could give Orson leverage. 

Makes sense.

And that is why I asked instead of jumping you by saying who cares what the inspector says, it's still wrong.

Well, that and the fact that you are an old timer here and I am but a stinking noob. On the job site you respect the old timers. I reckon a forum like this ain't any different.


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## Ron The Plumber (Oct 10, 2006)

Your input and anyone else giving input is always good, and right now Orson has no clue if the inspector seen this, which if he is to pull some leverage on the plumber to get him make this change/s, it might come down to just that, I don't think he seen it, any inspector would say fix the corroded pipe if he saw it, and you can bet he would have said something about the reduction in the supply.

Welcome to the forum glad to have you on here


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## neolitic (Apr 20, 2006)

22rifle said:


> Well, that and the fact that you are an old timer here and I am but a stinking noob. On the job site you respect the old timers. I reckon a forum like this ain't any different.


That, and never argue with a cat
that has automatic weapons. :laughing:


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