Heat Trace - Electrician Talk - Professional Electrical Contractors Forum
CLICK HERE AND JOIN OUR COMMUNITY TODAY, IT'S FREE!
Go Back   Electrician Talk - Professional Electrical Contractors Forum > Electrical Trade Topics > Industrial Electrical Forum


Like Tree5Likes
  • 1 Post By just the cowboy
  • 1 Post By joebanana
  • 2 Post By glen1971
  • 1 Post By Byron J Kessler
Reply
 
Thread Tools Display Modes
Old 10-18-2018, 01:09 PM   #1
Vacated
 
Wiresmith's Avatar
 
Join Date: Feb 2013
Location: United States
Posts: 1,454
Rewards Points: 2,844
Default Heat Trace

any heat trace aficionados out there?

1)why do you offset the heat trace slightly off center-line on outside radius', to reduce chance of damage? or so hard/heavy over-sized insulation doesn't put excess pressure on trace?

2)is wrapping the outside of flange better? i would think you would be getting the heat to the coldest part and keeping everything closer to the same temperature that way, everything would be more of an even temperature and with self-reg your heater would produce more heat when/where it is actually needed.

thanks
Attached Thumbnails
Heat Trace-outside-radius.png  

Heat Trace-flange.png  

Wiresmith is offline   Reply With Quote
Join Contractor Talk

Join the #1 Electrician Forum Today - It's Totally Free!

ElectricianTalk.com - Are you a Professional Electrical Contractor? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's the leading place for electricians to meet online. No homeowners asking DIY questions. Just fellow tradesmen who enjoy talking about their business, their trade, and anything else that comes up. No matter what your specialty is you'll find that ElectricianTalk.com is a great community to join. Best of all it's totally free!

Join ElectricianTalk.com - Click Here JOIN FOR FREE


Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ElectricianTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

Sponsored Links
Advertisement
 
Old 10-18-2018, 01:52 PM   #2
Petulant Amateur
 
99cents's Avatar
 
Join Date: Aug 2012
Location: Perky Nipples, Canada
Posts: 20,768
Rewards Points: 11,903
Default

It's not really an offset, you just want extra around the flange in kind of an exaggerated "S", keeping in mind that you don't want to overlap self reg.

Edit: I see what you're saying now that I look at it closer. I am not sure why they are suggesting a different orientation around the bend other than there is a little more surface area to cover.

Last edited by 99cents; 10-18-2018 at 01:57 PM.
99cents is offline   Reply With Quote
Old 10-18-2018, 01:58 PM   #3
Senior Member
 
just the cowboy's Avatar
 
Join Date: Sep 2013
Location: Colorado
Posts: 1,636
Rewards Points: 18
Default

I think
#1 is for motion so it has room to move if needed.


#2 is dual purpose extra heat for flange base, and extra cable for opening pipe at later date.
glen1971 likes this.
__________________
A cowboy may get thrown down, but he always gets up and walks forward and don't look back at what thru him.
just the cowboy is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 10-18-2018, 02:51 PM   #4
Senior Member
 
Join Date: Dec 2010
Location: So.Cal.
Posts: 3,585
Rewards Points: 7,109
Default

1) more surface area?
2) more slack for changing the gasket, installing a blank?
glen1971 likes this.
joebanana is online now   Reply With Quote
Old 10-18-2018, 04:30 PM   #5
Vacated
 
Wiresmith's Avatar
 
Join Date: Feb 2013
Location: United States
Posts: 1,454
Rewards Points: 2,844
Default

1) it is for more surface, what i mean is they say in technical note 2 "do not install heater on on very back or throat of pipe"

2)yes it is for service and additional trace, both ways require the same amount of allowance(extra trace at flange) but one shows the trace on the outside of the flange and the other shows the extra trace beside the flange, isn't outside much, much, better?
Wiresmith is offline   Reply With Quote
Old 10-18-2018, 08:42 PM   #6
Senior Member
 
Join Date: Oct 2012
Location: Alberta Rockies
Posts: 2,725
Rewards Points: 3,808
Default

From what I know...
1) Heat trace is installed at the 4:00 or 8:00 position on a pipe for a few reasons:
a) Liquids lay in the bottom half of any pipe, so this will prevent it from freezing.
b) The heat will radiate out and has a tendency to rise, so if it is on the lower half of the pipe it will radiate up.
c) Protect it from damage from things falling on or stepping on it.
d) It is usually on the outside of the radius as it is the longer side, and will heat the inner diameter easier than a shorter length trying to heat a larger area.

Their note about not on the very back of the pipe, may have to do with thermal expansion of the piping, in some cases. Steel will expand at a different rate than the copper in the heat trace..

2) Flanges have additional heat trace because:
a) They are a giant heat sink and will take more heat to ensure that any liquids that rest in any low spots will not freeze. This is similar to valves, pipe shoes, etc.
b) Makes it easier to replace a gasket or install a spade. On valves to remove the valve.

When I've done flanges, I tape close to the flange, then pull a loop so that it can almost wrap the flange. Then tape the trace to the pipe on the other side of the flange. Tape the flange and move on.

Crossing self regulating heat trace is not as critical as MI trace. It will cause the trace to prematurely (falsely) reduce the heater output and could cause process issues..

If heat trace isn't insulated or isn't touching the pipe, it won't be as effective if it was installed properly... I know it seems basic, but....
drsparky and Wiresmith like this.

Last edited by glen1971; 10-18-2018 at 08:44 PM.
glen1971 is offline   Reply With Quote
The Following User Says Thank You to glen1971 For This Useful Post:
Wiresmith (10-20-2018)
Old 10-18-2018, 08:47 PM   #7
Senior Member
 
Join Date: Oct 2012
Location: Alberta Rockies
Posts: 2,725
Rewards Points: 3,808
Default

Remember that you may have to double up the runs of heat trace depending on the pipe diameter.. That would change how flanges, valves, etc are done..
glen1971 is offline   Reply With Quote
Old 10-20-2018, 11:10 AM   #8
Vacated
 
Wiresmith's Avatar
 
Join Date: Feb 2013
Location: United States
Posts: 1,454
Rewards Points: 2,844
Default

Quote:
Originally Posted by glen1971 View Post
From what I know....
that expansion of the pipe makes sense for putting it on 4 or 8 o clock too and not 6 o clock, if you have vertical bends in a vertical run of pipe the pipe could expand and put tension on the trace. i never thought of that, thank you all.

i think the expansion damage is more of the reason for calling 4 and 8 than just saying bottom of pipe or other way of saying it, the expansion of the pipe is possibly more likely to damage it/strain it then something falling on it.

glen,
which pictorial most looks like how you tape the flange, the black and white(top) one or the orange(bottom) one, i'm thinking the orange way would be better because it would keep all of the pipe and its parts all at a closer temperature to each-other. the thing that is coming to mind is expansion and contraction at a gasktet, you would want the piping members temperature(because of size change (expansion and contraction)) to stay rather stable, i think it might make the joint seal more reliable over the long run. have any thoughts on this? i know i'm just splitting atoms here but that's just something i do, if there's a best way to do something why not do it the best way.
Wiresmith is offline   Reply With Quote
Old 10-20-2018, 01:06 PM   #9
Senior Member
 
Join Date: Oct 2012
Location: Alberta Rockies
Posts: 2,725
Rewards Points: 3,808
Default

Quote:
Originally Posted by Wiresmith View Post
that expansion of the pipe makes sense for putting it on 4 or 8 o clock too and not 6 o clock, if you have vertical bends in a vertical run of pipe the pipe could expand and put tension on the trace. i never thought of that, thank you all.

i think the expansion damage is more of the reason for calling 4 and 8 than just saying bottom of pipe or other way of saying it, the expansion of the pipe is possibly more likely to damage it/strain it then something falling on it.

glen,
which pictorial most looks like how you tape the flange, the black and white(top) one or the orange(bottom) one, i'm thinking the orange way would be better because it would keep all of the pipe and its parts all at a closer temperature to each-other. the thing that is coming to mind is expansion and contraction at a gasktet, you would want the piping members temperature(because of size change (expansion and contraction)) to stay rather stable, i think it might make the joint seal more reliable over the long run. have any thoughts on this? i know i'm just splitting atoms here but that's just something i do, if there's a best way to do something why not do it the best way.


The amount the pipe would expand and contract would depend on lots of factors, such as length, operating temperature, temperature fluctuations, and if there bends in it to allow expansion or not. And depending on how long your heat trace is could influence strain issues..


Personally, neither of them. The orange one has the trace on the top of the pipe, and the black it doesn't really look like it's hitting the thickest part of the metal.. If I'm tracing a line and I'm on the same side as the trace, I'd tape just before the weld on the flange. Then form the loop so it passes on the underside of the flange and comes back around to just past the top of the flange, so it is nearer to me. Then I'd tape a couple of spots past the flange, to continue the tracing run and hold it in place. Then in roughly the center of the loop, put a couple of wraps of tape, and use that to help pull the trace around the flange and hold it in place and tape it over the gap by the studs. The rest of the trace I'd tape to the edges of the flange, as the orange picture shows. Keep in mind, it is real easy to draw something that looks nice and pretty, but lots of times the heat trace won't bend anywhere near as neatly for you, so you make it touch the flange or fitting the best you can.


As for expansion and contraction at the joint, I doubt that would be an issue. The studs will be torqued and it shouldn't move a bit.. The excess on the flange is more to add the heat that the excess metal in the flange absorbs.
glen1971 is offline   Reply With Quote
The Following User Says Thank You to glen1971 For This Useful Post:
Wiresmith (10-20-2018)
Old 10-20-2018, 05:17 PM   #10
Junior Member
 
Join Date: Oct 2018
Posts: 7
Default

We offset because of hydrates. This becomes important in high pressure most of the time explosive gas transport. On the back side of the elbow is where the heavy wet gas pushes to as it travels the bend of the pipe. If this is a cold spot it can form ice on the inside of the pipe. Once ice is formed it can let go and be propelled down the pipe like a bullet. Not a good situation.
Dry gas pipes are not traced.

The second topic about flanges and valves. Follow the client spec or bible. It changes for all of them. Different liquids or gases different wattage of trace number of passes all feed into what is done and requested. But yes valves and flanges are heat sinks or the reverse of that cold sinks. They need more trace on them.
Byron J Kessler is offline   Reply With Quote
The Following User Says Thank You to Byron J Kessler For This Useful Post:
Wiresmith (10-20-2018)
Old 10-20-2018, 06:09 PM   #11
Senior Member
 
Join Date: Oct 2012
Location: Alberta Rockies
Posts: 2,725
Rewards Points: 3,808
Default

Quote:
Originally Posted by Byron J Kessler View Post
We offset because of hydrates.
Never heard of that being a reason before, but could be..


From Thermon's guide:


Elbows: Locate the cable on the outside of an elbow to provide sufficient heat to compensate for the added piping material.



glen1971 is offline   Reply With Quote
Old 10-20-2018, 06:27 PM   #12
Junior Member
 
Join Date: Oct 2018
Posts: 7
Default

Quote:
Originally Posted by glen1971 View Post
Quote:
Originally Posted by Byron J Kessler View Post
We offset because of hydrates.
Never heard of that being a reason before, but could be..


From Thermon's guide:


Elbows: Locate the cable on the outside of an elbow to provide sufficient heat to compensate for the added piping material.


When reviewing the thermos quote and break it down the elbow when compared to a piece of straight pipe has more metal per length. Which in turn yes needs more heat. Without the heat could cause freezing of the fluid inside the pipe. In the case of hydrates, water causing ice. The Thermon quote is totally correct and general. I agree the description I gave is in particular for oilfield construction and describes the results that can occur. 90% of my experience is in oilfield construction. Hydrates moving inside a pipe have been known to shake and move pipes of 36” diameter laterally up to 12”. A very dangerous situation.
glen1971 likes this.
Byron J Kessler is offline   Reply With Quote
The Following User Says Thank You to Byron J Kessler For This Useful Post:
Wiresmith (10-23-2018)
Old 10-22-2018, 08:24 PM   #13
Senior Member
 
Join Date: Nov 2008
Location: east coast
Posts: 1,871
Rewards Points: 2,194
Default

The true reason for insulating heat traced pipe is to cover up bad heat trace jobs.

I have put that stuff on by the mile not good work. We also had to cover our tracing with aluminum foil tape.

LC
__________________
What tools do I need to carry? Use the NEC as your guide keep all your tools ACCESSABLE but keep your everyday tools READILY ACCESSABLE.
Lone Crapshooter is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Roof Heat trace cable WronGun Commercial Electrical Forum 2 07-30-2018 08:29 PM
Heat Trace installed in drain line Kunolop Commercial Electrical Forum 17 03-22-2018 09:09 PM
Heat trace WronGun Residential Electrical Forum 25 10-02-2017 06:02 AM
what is the hot and neutral of this kind of heat trace cable ? mike883 General Electrical Discussion 15 07-18-2017 01:02 AM
MI Heat Trace glen1971 Industrial Electrical Forum 8 01-21-2017 06:14 PM


All times are GMT -4. The time now is 07:49 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Our Pro Sites Network
ContractorTalk.com | DrywallTalk.com | HVACSite.com | PaintTalk.com | PlumbingZone.com | RoofingTalk.com