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Up Topic Welding Industry / General Welding Discussion / 6" streamline growth???
- - By Rig Hand (***) Date 12-20-2009 02:00
I have a piping project that involves about 250' of 6'' pipe that will be a stream supply line. My question is how much will this line grow? Operating temp. is around 200 degrees and operating pressure is around 15 psi. I have no "real" room for a expantion loop, is thier other opions? Can stainless flex hose be used? Thanks for the help
Parent - - By dbigkahunna (****) Date 12-20-2009 03:16
Do they want you to engineer and build this? Will this fall under B31.1? Can you use stainless flex hose? Is the system carbon steel and is the flex compatable with the carbon. Is the system going to be insulated? (there goes the flex).
Maybe the owners skipped a step, like engineering and expect you as the fabricator to do it for them.
Parent - - By Rig Hand (***) Date 12-20-2009 03:53
Yes, this is probably a 250K project. They called yesterday at 6:50 a.m. and wanted to know if and when I could start. No advance notice, no bid, no plan, no drawing, but needs to be done by the 11th.
I went and looked at it today I'm not an engineer just a pipeliner, I do mainly station work so I know the welding and fitting part, but the rest of this is up in the air. I don't know how some of these plant/project managers keep thier jobs, but I'm past that. Just gonna do the best I can with what I have to work with.

the 6'' will supply several 2'' steam lines that are used to heat concrete forms (pre-cast wall panels). So I'm not sure what code that is under :) They don't even have drawings so I didn't get as far as what codes or welding procedures or processes. Its the blind leading the blind. LOL

Please, I'm just looking for some info on the growth of the 6''
Parent - By Tyler1970 (***) Date 12-20-2009 04:41
At 275 F its 1.61 in At 100 foot. That chart i found has no psi. so i am guessing thats under no pressuer. 'from 70 f to 275 f 1.61
Dont know if that helps ya any
Parent - By joe pirie (***) Date 12-20-2009 06:14
Don't forget the roller hangers the . The star guides,  The shoes and cleats.
What happens when the 6" line expands and you don't have your branch
connections engineered correctly. if your coils are encased in concrete
thats not gonna move youre going to have a big problem when your steam line starts moving.
Steam is nothing to fool around with.
Parent - - By joe pirie (***) Date 12-20-2009 06:25
operating pressure is only 15psi  lol lol  Don't forget the expansion rate of steam
your operating pressure will be much greater. they make carbon steel thrust absorbers
similiar to a big shock absorber. what about your steam traps, condensate line etc
you wonder how plant managers stay in business I wonder how welders stay in business when they
don't have a clue what their getting involved in. Just because . you have a welding rig does not make you a qualified
mechanical contractor. I love the blind leading the blind comment you hit that right on the head
Parent - - By Rig Hand (***) Date 12-20-2009 13:10
They "think" they know were and how they want thier steam traps, and mud legs. thier is a 3'' and a 2'' condensate return line.

I have already informed them that I am not a engineer nor do I care to be. I'm going to build it how they want. If it don't work it doesn't make a sh!t to me, I already have a full time job, This one little project ain't nothing to me and they know it.

The last mechanical contractor to work there cut a 4X3X2 reducer out of 4'' pipe with a torch. heated it all up beat it together and ran a cap over all of it, I'll try and get a picture of it sometime for you. Anyways thanks for all the help,  I guess.
Parent - By 803056 (*****) Date 12-20-2009 15:46
It may be nothing to you yet, but it will be if it fails in-service and someone is scalded by the hot steam. The lawyers will come out of the woodwork and you will be stuck holding the poopie end of the stick.

As stated by another responder and you, you are not an engineer nor are you a licensed mechanical contractor. Do you have a copy of the applicable codes; possibly ASME sections B31.1, Section IX, Section II, Section V, the local building ordinances, state building ordinances, etc.? You could be exposing yourself to legal problems even if no one is hurt in a unplanned release of steam. I know that in my home state anyone working with steam has to be licensed by the state, including the welder. 

Good luck.

Best regards - Al
Parent - - By dbigkahunna (****) Date 12-20-2009 18:23 Edited 12-20-2009 18:33
RH,
Quarter million dollar project?
Expansion on 6 inch pipe, figure 4 inches
Shoot just use 2 sets of double 90's along the line and call it good. Need 18 inches clearance.
5p stringer and 7018
Should work.But I am not a engineer. And I am not recommending it.

If the company could not care about doing the front end, why are you concerned about things like expansion loops on the back end. I mean no disrespect to you and applaud you for doing some research. I could not recommend components for you to use because if there is a failure and you state in a deposition you took my advice off a internet forum, then I get pulled into the lawsuit. And there are lawyers who will do this.
And while I understand there is personal pride involved here, if the company does not care how it is done, why would they care if a expansion joint is proper or even put in. Your view of putting it like they want not meaning chit to you to me means you have not gone through a lawsuit. You will find out real quick it DOES mean chit to you! If your fabrication causes the company to loose 5 million on their product because you did it from the seat of your pants, who will pick up the tab.
You got insurance?

B31.1 puts the responsibility of adherence to the code on the fabricator/contractor. That would be you. If there is a failure, do you want to bet your company and possibly your families financial future on doing this project. If you do, pick up B31.1, do your best and good luck.
Parent - - By Rig Hand (***) Date 12-21-2009 00:32
The piping itself is not a quarter mill. but the overall expansion is.

Anyways I went back over there today and talked with the project manager and plant manager, they are going to (well someone in their company will) contact an engineering firm tomorrow. I don't think I'll be the one that will end up doing the work, but after all of this I'm kind of glad.

I was wanting to know if there was any products out there that were designed for "in-line" expansion and contraction. Thought maybe I could pass this info on to the PM.

Thanks anyways tho.
Parent - By boiler tube (*) Date 12-21-2009 00:56
Hey rig hand
They do make an inline expansion compensator, we have used them in steam tunnels where there is no room for loops. you may need more than one on a run that long.
You have to anchor the pipe and need to use pipe guides just like you would with a loop. Your pipe supplier should be able to get you the infomation for them, if they cant let me know. Hope that helps

Good luck
Ray
Parent - By swsweld (****) Date 12-21-2009 03:38 Edited 12-21-2009 03:42
http://www.spiraxsarco.com/resources/steam-engineering-tutorials/steam-distribution/pipe-expansion-and-support.asp#head23
This link has a variety of useful info including sliding joint, expansion bellows and more.

http://www.dmeexpansionjoints.com/thermal-expansion.htm
This one has a good chart for thermal expansion.

http://chat.augustachronicle.com/stories/1996/12/06/met_200976.shtml
Bad design causing water hammer was the culprit

http://www.kirsner.org/pages/forensicResAlt.html
More steam/water hammer problems

http://dukechronicle.com/node/36524
Last year at Duke University Ray Cofer was killed by a steam line burst due to water hammer. He had told them about the problem earlier but nothing was done.

>“Ray Cofer’s death was a great tragedy for the Duke community, and I think everybody here joins with his family in their grief,” he said. “We know that his death was an accident that Duke itself could not have prevented.”


Yea, right.

Good work if they do the engineering, details and provide materials. If not it is very risky.
Good luck to you either way. Hope you are busy enough with or without this job.
Parent - By DaveBoyer (*****) Date 12-21-2009 04:06
http://www.flexiblesolutionsinc.com/  This is My cousin's company, They have just what You are looking for.
Parent - By PipeIt (**) Date 12-24-2009 16:21
15# steam is more then 200 degrees, ref: a Pressure Temperature relationship  tables/charts ( http://www.boilerroomservices.com/Facts/SteamTables.pdf ) you can find them on the Web.

My rule of thumb for expansion on carbon steel. .0000567 x (Operating Temperature) - (Temperature when installed) x total footage.

EXP:

500' of steam pipe with an operating pressure of 15# (250deg) installed on a 75 degree day.

(250-75) x (500') x (.0000567) = Total Expansion or in this case (around 5")

http://www.weldbend.com/Technical%20Data/Thermal%20Expansion%20For%20Carbon%20Steel%20Pipe/thermalexpansion.htm

The Weldbend Chart puts it just north of 4" not sure what value they are using.
Parent - By js55 (*****) Date 12-24-2009 18:31 Edited 12-24-2009 18:38
ASME B31.3 has thermal expansion tables.
But let me ask, is there no design engineer on this thing? How do you know the wall thickness is right?
Who did the calcs? Do they not have access to COE data?
Oh, and who is going to accept the liability on this?
You?
I'm guessin your client thinks so.
Do you really want to?
Up Topic Welding Industry / General Welding Discussion / 6" streamline growth???

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