# 3/4" pex pipe in the ground?



## younger-plumber

I have met a plumber who tells me stories of how they put 3/4" px pipe in the ground for main lines...is that legal? or safe? just curious because i was always taught poly and pvc...


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## Ron

Code approved here.


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## younger-plumber

It may just be me..im just used to the much thicker tougher looker black piping as apposed to the slender pipe.


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## Ron

Pex pipe has the same ID as Copper, we do run 1" or larger for our water service lines.


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## ROCKSTARPLUMBER

Poly? What kind of poly?


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## SummPlumb

I run pex for all residential main lines. No joints, easy to fix when the power company cuts it. It is easy to tie in on both ends. No waiting on glue to dry.


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## futz

younger-plumber said:


> I have met a plumber who tells me stories of how they put 3/4" px pipe in the ground for main lines...is that legal? or safe? just curious because i was always taught poly and pvc...


I use pex for water services and in-building underslab lines routinely. Pex IS polyethelyne - basically it's just cooked a different way to cross-link it, and died a different color. Don't tell anyone I told you this, but in a pinch you can crimp a pex ring and fitting on black poly tube, providing it's the right grade (wall thickness). Inspectors would hate that though, so don't do it. :laughing:

For 1/2" in-house underslab waterpipes I first run 1" utility grade poly and attach both ends. Then I push 1/2" pex (I use up all my heating loop scraps for this) through and then tape up the ends. Don't try it on sleeve much longer than about 20' - 25' as the friction gets bad enough at that length that you can't push that "string" any further.

Here's an example. Three lines - you can see two of them coming up in the background in the laundry - the other comes up at the toilet you can just barely see at the near right.









For water services I only sleeve going through concrete walls/footings and where it comes through the slab, again with utility grade poly-e.

I've seen pex survive being run through crushed stone gravel. It's tough stuff. I'd prefer to have some sand around mine though.


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## SummPlumb

That looks good futz. If I sleeve pex, I use foam insuation or pvc thru a wall or under a footing. Us rebels in da South don't use radiant floor.


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## AKdaplumba

SummPlumb said:


> That looks good futz. If I sleeve pex, I use foam insuation or pvc thru a wall or under a footing. Us rebels in da South don't use radiant floor.


seems to be common to use a piece of ABS for sleeving now.


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## LEAD INGOT

Ron said:


> Pex pipe has the same ID as Copper, we do run 1" or larger for our water service lines.


 Check me if I'm wrong here Ron, but pex has the same OD as copper, not ID.


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## OldSchool

Pex Code Approved in Ontario for main service


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## Ron

LEAD INGOT said:


> Check me if I'm wrong here Ron, but pex has the same OD as copper, not ID.


I got it backwards, thanks for the correction,


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## plumb4fun

In using Wirsbo pex underground, they reccommend a sanded trench and running the pipe in a slightly wavy pattern to the point of connection. Sounds like PVC would be quicker and easier.


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## M5Plumb

New Construction...



younger-plumber said:


> I have met a plumber who tells me stories of how they put 3/4" px pipe in the ground for main lines...is that legal? or safe? just curious because i was always taught poly and pvc...


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## SummPlumb

Just buy the pex by the roll. You can get it in 300' rolls. No joints. It is the only economical way here to do a slab house. It comes in red and blue to make the rough in easy.


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## futz

SummPlumb said:


> Just buy the pex by the roll. You can get it in 300' rolls. No joints. It is the only economical way here to do a slab house. It comes in red and blue to make the rough in easy.


Umm... Huh? Of course you buy it in rolls! :laughing::laughing:

What did you think we were talking about - jointing together 20' sticks underslab??? That would be insane, not to mention really, really stupid (and illegal)!


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## AKdaplumba

what happens when you run out of red pipe and your inspection is in afew hours?


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## futz

AKdaplumba said:


> what happens when you run out of red pipe and your inspection is in afew hours?


Just use whatever you have. Who cares about color? At rough-in time untape one end at a time and blow at the other end. Mark them H and C with a Sharpie.


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## AKdaplumba

futz said:


> Just use whatever you have. Who cares about color? At rough-in time untape one end at a time and blow at the other end. Mark them H and C with a Sharpie.


that was sarcasm...


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## markb

Just used pex last week for a service for the first time. I was getting really worried because it seemed to spin too easily in the corporation coupling. It held fine after the water was turned back on, but I was questioning wether or not it would hold. 

Anyone else have this problem?


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## Redwood

markb said:


> Just used pex last week for a service for the first time. I was getting really worried because it seemed to spin too easily in the corporation coupling. It held fine after the water was turned back on, but I was questioning wether or not it would hold.
> 
> Anyone else have this problem?


Because of the nature of the barbs and the slick plastic fittings will turn but not leak.


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## Bill

This is what I have always used underground

http://b.shoponlineaabbcc.com/cresline-plastic-18340-hd100-sidr-15-plastic-polyethylene-pipe


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## M5Plumb

I'd use that to sleeve my Wirsbo or Rehau in river rock areas here in PDX / Vancouver.:yes:



Bill said:


> This is what I have always used underground
> 
> http://b.shoponlineaabbcc.com/cresline-plastic-18340-hd100-sidr-15-plastic-polyethylene-pipe


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## futz

markb said:


> Just used pex last week for a service for the first time. I was getting really worried because it seemed to spin too easily in the corporation coupling. It held fine after the water was turned back on, but I was questioning wether or not it would hold.


What kind of fitting? Did you use a stainless insert?


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## markb

What do you mean by stainless insert? I just put it into the corporation cupling and tighened the thing. Do they make inserts for pex in corporation cuplings like the inserts we use when we use 3/8" compression fittings with plastic 3/8" pipe?


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## futz

markb said:


> What do you mean by stainless insert? I just put it into the corporation cupling and tighened the thing. Do they make inserts for pex in corporation cuplings like the inserts we use when we use 3/8" compression fittings with plastic 3/8" pipe?


If you're using Mueller or Ford or other similar compression fittings and you put poly or pex pipe in them without a SS stiffener insert then you are going to have harsh problems down the road. Sooner or later one will blow off. That plastic pipe won't get grabbed by the fitting's tooth ring properly and it will creep out if it can. Sometimes the dirt will hold things together and it'll just leak a bit and no one will ever know. But other times it will just work its way out and boom, you have a huge expensive leak bubbling up under someone's driveway. *Don't forget to put in your inserts!*


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## HandsomeMike

I know in Saint Charles County, Mo. they have been using HDPE for services for at least twenty five years. Pex is approved for underground, just no sunlight.


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## Miguel

markb said:


> What do you mean by stainless insert? I just put it into the corporation cupling and tighened the thing. Do they make inserts for pex in corporation cuplings like the inserts we use when we use 3/8" compression fittings with plastic 3/8" pipe?


No insert? You gotta use the SS insert sleeves or it'll blow off!!!
Hopefully it doesn't but geez. (It should hold as long as the temps remain low)

We normally use HDPE CTS sized (not 1404 PE that uses the barbed insert fittings). It's thinner walled than the 75# black PE waterline but it's a different grade and much tougher. 160# & 200#. I'd equate it to PEX for durability but I've never used PEX other than the old "Blueline" that was apparently made for service lines.
We use Muehler or Ford depending on the dimension ratio (ie: DR11 vs DR17. CTS is DR9) but plastic requires the SS sleeves or "inserts" to make a viable joint.

Within city limits they require copper so no sleeves required but it sure ups the install price big time!


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## markb

hhmmm interesting. Well, while I have my fingers crossed, can someone post a link to the sleeves? That way I can print it out and get my wholesaler to order some.


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## futz

markb said:


> hhmmm interesting. Well, while I have my fingers crossed, can someone post a link to the sleeves? That way I can print it out and get my wholesaler to order some.


If they're selling the fittings they must have inserts for them. They come from the same company. Not "sleeves" - ask for inserts.

Here's a link to Ford's site - Section J - with a crappy pic of an insert stiffener at bottom right.

Here's a better pic of what they look like. This is a CTS stiffener, by AY McDonald. I've used these, but now I use Ford ones:


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## markb

futz said:


> If they're selling the fittings they must have inserts for them. They come from the same company. Not "sleeves" - ask for inserts.
> 
> Here's a link to Ford's site - Section J - with a crappy pic of an insert stiffener at bottom right.
> 
> Here's a better pic of what they look like. This is a CTS stiffener, by AY McDonald. These are the ones I use:



Ok. Thanks for the tip. But just so I am sure, we are both talking about pex being used in brass corporation couplings right? Not PE and not brass ring compression fittings. I've just never seen these before.


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## futz

markb said:


> Ok. Thanks for the tip. But just so I am sure, we are both talking about pex being used in brass corporation couplings right? Not PE and not brass ring compression fittings. I've just never seen these before.


Yes, pex or polyethylene (any plastic pipe) in brass corporation fittings. Since these things are so ridiculously hard to find on the web I walked out to the shop, found a 1" x 3/4" Ford coupling with inserts and shot some pictures. Here they are:

































As you can see, Ford makes the inserts as well. If the forum-resized pic is too small for you to see it just click on it once, wait till it expands and then click on it again to see it full size (900x600). If your browser is sized very small (laptop/netbook) you may need to click it one more time to see it full size, as the browser may resize it so you can see the whole thing. Click on <Back> to return to the post.


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## futz

The forum software only allows five pics per post, so here's the last one:


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## Miguel

Nice, futz.

Also, Uponor (Wirsbo) makes the inserts for PEX. Not sure if it would make a difference but since the dimension ratios are slightly different it might.


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## futz

Redwood said:


> Because of the nature of the barbs and the slick plastic fittings will turn but not leak.


A corporation fitting does not have barbs. You're thinking of crimp fittings.

Pipe in a tightened corporation fitting should *NEVER* *NEVER* *NEVER* be able to spin or turn in the fitting. If it does and you bury it that way then you are soon going to be having a *very* bad time. That thing is going to blow apart and the insurance companies and lawyers will be all over you.


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## futz

Miguel said:


> Also, Uponor (Wirsbo) makes the inserts for PEX. Not sure if it would make a difference but since the dimension ratios are slightly different it might.


I've used different brand inserts over the years. They were selling glass-filled nylon ones for a while. Doesn't matter as long as the insert is made for the type of pipe you're using. Any insert is better than no insert.

Those Ford ones are what I've been using for probably the last decade or so though. Cheap and absolutely reliable. :thumbup:


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## markb

I saw the sleeves in the uponor catalog but didn't know what they were. Thanks guys!


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## royals91

Uponor has sleeve for 1/2 and with 3/4 it comes pre-sleeved. 

Pre-sleeved AquaPEX tubing is used in hot and cold water distribution systems. The high-density polyethylene (HDPE) corrugated sleeve provides protection for installations in concrete slabs or soil, and allows for removal and replacement of the tubing if required.


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## royals91

here is a picture .


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## Miguel

Thanks royal. Handy stuff for running under slabs and wotnot.

The sleeves we were referring to are the stainless inserts that are flared on one end, used to stiffen the end of the plastic tube so you can safely use a compression fitting on it.


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## njoy plumbing

AKdaplumba said:


> what happens when you run out of red pipe and your inspection is in afew hours?


 RED felt marker:icon_cheesygrin:


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## devin horvath

i would only run apex under ground from the meter in areas that need be fished, like under tricky concrete obstacles like wide side walks or landscape walls. foam insulation inside of wet new concrete or a pvc sleeve, yes. one should stay weary of the shuvels that may pierce that delicate memory poymer. i use the **** thoe- where i feal its safe...


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## 1plumb4uall

*Pex*



LEAD INGOT said:


> Check me if I'm wrong here Ron, but pex has the same OD as copper, not ID.


*I use Upnor Aqua Pex pipe and fittings its ID is true 1/2" / 3/4" / 1" Unlike some of the other brands of Pex pipe and fittings, where 1/2" ftgs are realy 3/8".*

*Most of the localities around here allow PEX water mains exept they require a special compresion ftg rather than crimp rings. :thumbup:*


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## Protech

Actually, that's not true. But yes, cold expansion pex fittings do have a slightly better flow rate thru the fittings.

If you build your systems with very few fittings then it really doesn't matter that much.



1plumb4uall said:


> *I use Upnor Aqua Pex pipe and fittings its ID is true 1/2" / 3/4" / 1" Unlike some of the other brands of Pex pipe and fittings, where 1/2" ftgs are realy 3/8".*
> 
> *Most of the localities around here allow PEX water mains exept they require a special compresion ftg rather than crimp rings. :thumbup:*


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## PLUMBER_BILL

futz said:


> The forum software only allows five pics per post, so here's the last one:
> 
> View attachment 5296


Excellent topic. Great Posts One question on C.T.S. Poly with SS flanged inserts. E.G. McDonald Fitt's How tight do you pull up the joint.
Some are saying pull the nuts till they shoulder. {McDonald} 
Same for other manufacturers ???


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## futz

PLUMBER_BILL said:


> Excellent topic. Great Posts One question on C.T.S. Poly with SS flanged inserts. E.G. McDonald Fitt's How tight do you pull up the joint.
> Some are saying pull the nuts till they shoulder. {McDonald}
> Same for other manufacturers ???


For Ford and Mueller at least, crank em till they bottom. That's not terribly tight. I use 10" pipewrenches on 1" fittings, and I'm not straining to get the nut bottomed on the thread.


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