proper heat source for bending pvc conduit

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PEDRO ESCOVILLA

Senior Member
Location
south texas
i've worked in the trades for 30 years, electrical since 1993, i recently relocate to anew are and see contractors usine what i call "big bertha" torches to heat pvc conduit for bending. i know this isn't right. drives me nuts to see this because 9 times out of 10 they burn it. any thoughts ?
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
If you are in the country and the heating blanket is broken then i guess you can use a torch or the exhaust of the car. other than that we will see all kinds of things that will drive us nuts. You do your job correctly by using the correct tools and be proud of it.

Thats all i can say.
 

iwire

Moderator
Staff member
Location
Massachusetts
352.24 Bends — How Made. Bends shall be so made that
the conduit will not be damaged and the internal diameter
of the conduit will not be effectively reduced. Field bends
shall be made only with bending equipment identified for the
purpose.
The radius of the curve to the centerline of such
bends shall not be less than shown in Table 2, Chapter 9.

But it is a real world out there .....
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
But it is a real world out there .....

To many, intent of the rule was to govern the means of heating the conduit, but that is not how it's worded. It only says 'bends' shall be made with identified equipment.

In most cases, the actual bending is done by hand.

Now, as I read the rule, it prohibits the use of EMT benders, like would be used with those spring things that supposedly allow PVC to be bent with EMT benders. (Which aren't identified for use with PVC)
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
If you are in the country and the heating blanket is broken then i guess you can use a torch or the exhaust of the car. other than that we will see all kinds of things that will drive us nuts. You do your job correctly by using the correct tools and be proud of it.

Thats all i can say.

I have found that a Wagner heat gun works great. It's fast, and it's really tough to scorch the pipe with it. I have never bent pipe with it, though. Sometimes it's many feet away from where I will do the actual bending.

My interpretation is that I did not violate the code. Since I used my hands to actually bend the conduit, I used no equipment to make the bends. I believe iwire sees it differently.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
i've worked in the trades for 30 years, electrical since 1993, i recently relocate to anew are and see contractors usine what i call "big bertha" torches to heat pvc conduit for bending. i know this isn't right. drives me nuts to see this because 9 times out of 10 they burn it. any thoughts ?

Here is the part that I see was violated

Bends shall be so made that
the conduit will not be damaged

If it's burnt, it's damaged. No matter what was used to heat it.
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
so, whats wrong with a "hot box" and /or a heat blanket? that;'s the way i was trained to do this stuff. torches are a no-no

heat box and blanket have been specifically designed for that purpose.


I guess i also agree with k8MHZ.
 

iwire

Moderator
Staff member
Location
Massachusetts
To many, intent of the rule was to govern the means of heating the conduit, but that is not how it's worded. It only says 'bends' shall be made with identified equipment.

In most cases, the actual bending is done by hand.

I have to say if I was inspector and you tried that line on me you would still get a red tag along with a hearty laugh. :p
 

iwire

Moderator
Staff member
Location
Massachusetts
I have found that a Wagner heat gun works great. It's fast, and it's really tough to scorch the pipe with it. I have never bent pipe with it, though. Sometimes it's many feet away from where I will do the actual bending.

My interpretation is that I did not violate the code. Since I used my hands to actually bend the conduit, I used no equipment to make the bends. I believe iwire sees it differently.

I do see it differently, IMO that is a fail.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
I do see it differently, IMO that is a fail.

Luckily, the inspectors around here see it my way.

If I got gigged for using a heat gun and my conduit was not damaged I would make an issue out of it. Now, if I did damage the conduit in any manner, I would concede to a rule violation.

So, you are telling me you would make an EC tear out a perfect run of PVC because he used a heat gun to heat it prior to bending? If you did that around here, you wouldn't last long as an inspector.
 

masterinbama

Senior Member
I must admit I use my Grill Master NG grill quite often on bigger pipe. I carry a small blanket with me always.Most big pipe I have to bend is for underground risers on service upgrades. I can figure out what offset I need when I bid the job and make a note on the paperwork.
 

iwire

Moderator
Staff member
Location
Massachusetts
So, you are telling me you would make an EC tear out a perfect run of PVC because he used a heat gun to heat it prior to bending? If you did that around here, you wouldn't last long as an inspector.

I am telling you that if I was an inspector I would enforce the code.

There are many heat guns and other tools out there identified for the purpose of bending PVC.

We own a couple of these http://www.hotbend.com/ there are nice when there is no power around for boxes or blankets.
 

Joethemechanic

Senior Member
Location
Hazleton Pa
Occupation
Electro-Mechanical Technician. Industrial machinery
If the conduit was bent, and bent right, how would the inspector have any idea what you used for heat?

BTW, back here at the shop, when i have to bend plastic, most times I use the steamer
 
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Joethemechanic

Senior Member
Location
Hazleton Pa
Occupation
Electro-Mechanical Technician. Industrial machinery
What's next, an inspector concerning himself with the forklift operator's certification back at the supply house where the conduit came from?
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
I am telling you that if I was an inspector I would enforce the code.

There are many heat guns and other tools out there identified for the purpose of bending PVC.

We own a couple of these http://www.hotbend.com/ there are nice when there is no power around for boxes or blankets.

And I would expect you to enforce the code. I feel, that if it were the intent to use identified devices for heating, then the word heating should be in there somewhere. It isn't. If that brings forth the question, 'Then how do you bend it without heating it?' you can, using a spring type insert, but THEN you have to use a bender not identified for use with PVC.

I don't see how a device that does not bend pipe can be identified for bending, but as you say, the labels indicate that they are.

If you gigged me for using a heat gun on a perfect PVC run I would argue, and likely successfully, that I did not use the heat gun to bend the pipe, and bending the pipe is what the rules specifically address.

Now, I try to be a reasonable person. If heat guns were notorious for damaging pipe, like torches are, and you as an inspector requested I use an 'identified device' I could see your point. But I don't think that is the case. It's no easier to damage a piece of conduit with a heat gun than it is with a blanket or a hot dog cooker. Even though they won't scorch the conduit, they can get it so soft it collapses, and that is damage and would be a code violation.

This would be a good poll for inspectors. I know for certain there are inspectors that have no problem with heat guns. (But then, they also deal with a fair amount of people using torches, so a heat gun is a step upward). In fact, I have never met an inspector that requires a specific tool for heating, so long as there is no damage. I have met inspectors that will look for microscopic signs of scorching if they think the conduit was heated with a torch and gig people for damage. I don't have a problem with that.

If the code read that heating shall only be done with devices identified for the purpose, then it would be clear that a paint stripping heat gun would not be allowed.

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

iwire

Moderator
Staff member
Location
Massachusetts
I don't see how a device that does not bend pipe can be identified for bending,

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

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

You have pointed out your opinion, my opinion differs.
 
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