proper heat source for bending pvc conduit

[iwire]

I know for certain there are inspectors that have no problem with heat guns.

I know that as well, I have also used almost any source of heat you can think of.

Neither of those facts changes my opinion of the code section.

 

[renosteinke]

Pedro, you're going to have to use the 'search' function if you want to see the rather recent thread on this topic - where I posted pics of my "PVC BBQ."

 

[K8MHZ]

In my opinion if you use a heat gun to form pipe it is a is a tool used to bend pipe.

My opinion would be the same as yours IF I use the heat gun to FORM the pipe. I am not. When I am done heating, the pipe is still straight. I use my hands for forming the pipe.

Now, if I continue using the heat gun while forming the pipe (which I would never, ever do), I concede that I would be using the heat gun to form the pipe and to be compliant I shall use a device identified for the purpose.

You have pointed out your opinion, my opinion differs.

Even with that little nuance thrown in??

Edited to add:

If you think we need an identified device for heating prior to bending, do we also need one for cooling after the bending?

 

[Joethemechanic]

Imagine that, a public official enforcing the codes they were hired to. Shameful

Can you imagine a world where every law, code, and regulation, was strictly enforced?

This is starting to sound like the arguement I had with the preacher one time. He said we should obey all of man's laws. At the same time he was driving up 95 without his seat belt on eating a big mac and taking a call from his wife.

I'm pretty sure that was the beginning of my "disfellowship" :happyno:

 

[Joethemechanic]

My opinion would be the same as yours IF I use the heat gun to FORM the pipe. I am not. When I am done heating, the pipe is still straight. I use my hands for forming the pipe.

Now, if I continue using the heat gun while forming the pipe (which I would never, ever do), I concede that I would be using the heat gun to form the pipe and to be compliant I shall use a device identified for the purpose.



Even with that little nuance thrown in??

Edited to add:

If you think we need an identified device for heating prior to bending, do we also need one for cooling after the bending?

If we need an "identified device" for all heating of the conduit, is the sun an "identified device"? because we need the sun to heat the conduit the first 500 F or so from absolute zero to ambient.

 

[Joethemechanic]

And seriously, don't you think the issue with bending plastic pipe is that we want to control where the neutral axis of the bend is? Really you want to use the internal stresses left over from the extrusion process to shrink the plastic on the inside radius, rather than to stretch the outside radius and compromise the wall thickness on the outside of the bend.

 

[MarkyMarkNC]

"I swear, Mr. Inspector.....we used a proper heating device to bend that PVC, and then the plumber sweated his pipes right over top of it and made those burn marks."

 

[Stevareno]

I'm guilty of using a torch to heat PVC for bending. Problem is, you won't be able to tell what I used for the heat source because I'm patient and don't damage the PVC.

In a pinch, I will pool some PVC glue in the dirt and make a campfire. Only problem with that is the smoke can discolor (note I did not say damage) the PVC calling in the question of how it was heated.

 

[K8MHZ]

I'm guilty of using a torch to heat PVC for bending. Problem is, you won't be able to tell what I used for the heat source because I'm patient and don't damage the PVC.

In a pinch, I will pool some PVC glue in the dirt and make a campfire. Only problem with that is the smoke can discolor (note I did not say damage) the PVC calling in the question of how it was heated.

I have it on good authority that grey automotive primer covers scorches and discolorations. It's also great to cover the markings and printing on the conduit. And, it's exactly the same color and texture. :thumbsup:

 

[kwired]

Your interpretation of the code seems to be that heating and bending are synonymous, and as I have pointed out, they are not.

Pedro, you're going to have to use the 'search' function if you want to see the rather recent thread on this topic - where I posted pics of my "PVC BBQ."

I have mentioned it before (I think in renostienkes thread) that you don't bend the pipe with the heater, you prepare the pipe for bending with the heater.

I have burned pipe in a hot box before - you can not leave it unattended or this happens. it is just as burned as with something other than hot box.

If NEC intends you to use only heating equipment designed for the purpose then maybe they should word it that way.

 

[Joethemechanic]

I have mentioned it before (I think in renostienkes thread) that you don't bend the pipe with the heater, you prepare the pipe for bending with the heater.

I have burned pipe in a hot box before - you can not leave it unattended or this happens. it is just as burned as with something other than hot box.

If NEC intends you to use only heating equipment designed for the purpose then maybe they should word it that way.

But what if you use controlled heat to bend the tubing. In the same way as you use a rosebud to heat the flange of a steel I beam in order to camber it?

 

[K8MHZ]

But what if you use controlled heat to bend the tubing. In the same way as you use a rosebud to heat the flange of a steel I beam in order to camber it?

I saw some ironworkers do that to a 40 foot long, 20 inch wide I beam in a power plant once. Just by using a rosebud in a diamond pattern on one side and some wet ceramic insulation on the other, they moved the end of the end over an inch just by using the heat to warp the beam so the bolt holes would line up.

It was pretty impressive.

 

[cmreschke]

I'm sorry but why can't you use a shoe type Bender or hand Bender with the spring item that you can get at supply houses? Aren't hand benders listed as bending emt or ridgid? 3/4 emt 1/2 ridgid I believe is what they state. Is pvc not called ridgid nonmetalic conduit? Or am I just way off base. Btw if inspector said I couldn't use that or heat gun or what have you we would have issues.

 

[K8MHZ]

I'm sorry but why can't you use a shoe type Bender or hand Bender with the spring item that you can get at supply houses? Aren't hand benders listed as bending emt or ridgid? 3/4 emt 1/2 ridgid I believe is what they state. Is pvc not called ridgid nonmetalic conduit? Or am I just way off base. Btw if inspector said I couldn't use that or heat gun or what have you we would have issues.

I don't know why I took so long to look up the definition of identified, but it does not require a marking, so my suggestion that an EMT bender was not identified for the use may have been in error.

Identified: "Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement."

So I also back peddle a bit and disagree with Bob even more, and would like to remove one nuance.

An electric heat gun is very recognizable as suitable for use with PVC conduit, even if heating is considered bending. It does not have to be marked so. A torch?? I would say not. But no way do I see an electric heat gun as not being recognized to be able to suitably perform the task in question.

Same for the EMT bender. It doesn't have to be marked, just suitable.

 

[Cow]

Wow....Iwire has got some of you guys all riled up.

The real world dictates your going to use whatever you have, but if it looks like you held a weed burner to the side of it, you're going to get called on it. Use a little common sense and don't burn your pipe like a rookie or brag to the inspector you used a campfire to bend it and I doubt you'll have a problem.

I realize some on here like to argue code till they're blue in the face(it is a code forum!), but jeez, you have to let some things go.....there are better things to worry about!

 

[elohr46]

I would have to say that during my time in the field I have overheated and collapsed PVC pipe with a hot dog device, it's trial and error depending on ambient temperatures, that being said, as a part time inspector I would not ask an electrician how he heated his conduit unless I saw evidence of burning or collapsing.