Schedule 80 PVC

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jmellc

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Durham, NC
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Facility Maintenance Tech. Licensed Electrician
I have rarely ever worked with Schedule 80 but helped a coworker make a sign frame with it. Rectangular frame used to hang a banner. Pipe, & sharp 90 plumbing elbows. He sanded the pipe ends and used pipe cleaner on them, then glue, but put no glue in the elbows. I was trained to put glue on both surfaces and have always done this. But he has made a lot of these frames and they have been holding up for a few years. I never sanded PVC either, new to me.

How do any of you glue Schedule 80?
 
I haven't used primer on conduit, because water is going to get in anyway, but I use heavy-duty PVC plumbing glue, not the gray PVC conduit junk.

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LarryFine said:
I haven't used primer on conduit, because water is going to get in anyway, but I use heavy-duty PVC plumbing glue, not the gray PVC conduit junk.

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I use the gray if I can't get clear or it's something I want to bust loose eventually like a box adapter if someone will notice I want to just silicone it in. I know the silicone on a box adapter is heresy but I've found it works well and others in the area do the same. Grey bad glue holds and is "legal" though but bustable.
 
LarryFine said:
I haven't used primer on conduit, because water is going to get in anyway, but I use heavy-duty PVC plumbing glue, not the gray PVC conduit junk.

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Larry I thought that also. We install 150' of 2" pvc and 2 months later we went back and ran the wires in the conduit. Honestly there wasn't a drop of water that we could detect. We were very surprised.
 
LarryFine said:
I haven't used primer on conduit, because water is going to get in anyway
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Dennis Alwon said:
Larry I thought that also. We install 150' of 2" pvc and 2 months later we went back and ran the wires in the conduit. Honestly there wasn't a drop of water that we could detect. We were very surprised.
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Yeah I don't think it's true that "pipes will always fill with water". I have seen plenty of dry pipes. I understand the physics of the condensation theory, but that doesn't seem to happen where I am. While I agree pipes OFTEN fill with water and it generally doesn't matter, there are some times it does and IMO primer should be used and joints made more carefully in these cases. This is primarily when you have a downhill run into a basement. Drilling weep holes on the outside is an option too, but you would have to have freely draining fill drained to daylight which you don't always have.
 
While water pipe and conduit are both PVC, there is a difference in the PVC. Water pipe has a harder finish ( don’t know technical details) so the primer softens the finish for the glue. Also water fittings are tapered, meaning when you glue the hydraulic force will push the pipe out. Conduit couplings are straight.
 
electrofelon said:
Sometimes I think there must be only like 27 people in all of human history who have read the instructions on the can of glue, but I am one of them and it says to apply to both surfaces.
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It's best to get data from the pipe maker.

Charlotte Pipe
"PVC Schedule 80 Pipe is for pressure applications and has a thicker wall than Schedule 40 pipe. It is highly durable, easy to install and has better sound deadening qualities than PVC and ABS Foam Core pipes. Installation requires the use of primer and solvent cement."

PDF page 55
 
FionaZuppa said:
It's best to get data from the pipe maker.

Charlotte Pipe
"PVC Schedule 80 Pipe is for pressure applications and has a thicker wall than Schedule 40 pipe. It is highly durable, easy to install and has better sound deadening qualities than PVC and ABS Foam Core pipes. Installation requires the use of primer and solvent cement."

PDF page 55
Click to expand...

Does Charlotte Pipe make an electrical PVC conduit? Only ones I know of being mfg by them is for water/sewer pipe. Never heard of a requirement or request for sound deadening as a desired listing for electrical PVC conduit.

The PVC used as electrical conduit has additional required elements to it's construction that may alter it's installation process regarding glue up VS the plumbing type of PVC. Some of the differences are the conduit is constructed to have UV tolerances not found in plumbing PVC and also has compound added to lower smoke emiting and fire ratings not found in regular plumbing PVC.

It is also recommended regarding conduit glue up to only apply glue to the male connection to prevent an internal "squish out" of the glue as the pieces are put together creating a clump inside that could potentially damage conductors as they are fed thru. To that how many will ream the inside male edges prior to installing?

PDF Pg 2,3

 
following directions mentioned, primers, cleaners, socket first... likely does make a stronger joint.

Not all electrical PVC runs necessitate such quality of a joint as compared to a pipe that must contain pressure. Bell ends on Electrical PVC in particular are not always that tight fitting that they will yield as good of a joint as other more precision made fittings often will either.
 
electrofelon said:
Yeah I don't think it's true that "pipes will always fill with water". I have seen plenty of dry pipes. I understand the physics of the condensation theory, but that doesn't seem to happen where I am. While I agree pipes OFTEN fill with water and it generally doesn't matter, there are some times it does and IMO primer should be used and joints made more carefully in these cases. This is primarily when you have a downhill run into a basement. Drilling weep holes on the outside is an option too, but you would have to have freely draining fill drained to daylight which you don't always have.
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I recall burying PVC conduit one time on hot humid day, a Friday. Came back Monday to pull conductors. There was no rain over the weekend, but my pull rope had somewhat significant moisture in it from underground run that had only been in the ground for two days. Had to be the humid air condensing on the cool walls of the underground run.
 
PVC is PVC, gray or white makes no diff. There may be some small diffs in final product (anti-UV additives,etc) but it's the same stuff, same glue, same primer, same process.

Gray for electrical work of course.

I wonder if Gray PVC is made in foam-core? I have never seen it, but if it's made would NEC allow foam-core PVC?
 
LarryFine said:
I haven't used primer on conduit, because water is going to get in anyway, but I use heavy-duty PVC plumbing glue, not the gray PVC conduit junk.

Yes: View attachment 2563166 No: View attachment 2563164
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To each his own.
FWIW: I'm a firm believer in using primer it does make a big difference in the conduits bonding together and helping to keep water out.
It's not perfect but I know that I did my best.
 
+1 on primer...it makes it tacky and gets rid of any crap...then glue on both ends.
 
I was always taught to twist back and forth a time or 3 as I set the joints as well. And definitely glue both sides.
 
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