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Up Topic Welding Industry / Welding Fundamentals / Need help with Flange fitting
- - By Tommyjoking (****) Date 01-29-2011 00:50
This is a weird question and I am sure there is a simple answer.    How do you clock pipe flanges to fit an existing setup that are all vertical pipe BUT they did not necessarily two hole the existing setup.....in other words the two hole is not 90 against their 90 elbows...or the flanges where welded in place mated and not two holed.................So what do I use setting flanges ( in the horizontal plane) to fly in place...a compass??   To simplify the scenario  lets say you where replacing a vertical pipe to long to shoot lines on....the flanges where welded in place in whatever position as they built it....you do not have that option, you must build it on the ground and it has to fit when they get it up there.   I do not know who did this but they were idiots.

THX to any and all who know the easy way to do this...I am kinda stumped (maybe just stupid).

Sincerely
Tommy
Parent - - By aevald (*****) Date 01-29-2011 01:11
Hello Tommy, not personally a pipefitter so my answers might draw a few raised eyebrows from those who are, but here goes: if I understand what you are up against, you are trying to replace sections of existing pipe that have been damaged or otherwise require replacement or rerouting to existing flanges. These sections(spools) have flanges on them, yet they aren't done with the proper 2 hole technique(out of level or otherwise disoriented). I believe I would still use the 2 hole pins, but I would substitute the level for a protractor or other angle finder of some sort for any horizontal flanges. Here is where I will be getting really strange, if you are talking about orienting a vertical flange in relationship to a horizontal one or another vertical one, I would use a compass and use the degrees that the compass gives for orientation while still using the 2 hole pins. Plumb bobs are also invaluable to help with replications and correctly locating difficult points.
     I am hoping that I understood the situation correctly and I also hope that my suggestions make sense in their own weird sort of way. Pictures would be great Tommy if they are allowed or you have the means. I will be interested to see the responses of others here as well. Best of luck and regards, Allan
Parent - - By DaveBoyer (*****) Date 01-29-2011 01:49
Allan, are You suggesting using a magnetic compass close to the pipe?
Parent - By aevald (*****) Date 01-29-2011 03:05
Hello Dave, the moment that you pointed that out I realized that there might be issues with that particular choice, point taken. There might certainly be magnetics that would affect using a compass. I was trying to address vertical rotational orientation by using an inclinometer of some sort, ie. digital protractor, or some sort of similar angle indicator. For the horizontal orientation I was considering a compass, in lieu of a compass(due to magnetics) I wonder if some form of GPS(we are in the age of technology) would allow for horizontal positioning replication. This is out there, I know, but it just might work. Best regards, Allan
Parent - By Pickupman (***) Date 01-29-2011 01:52
I'm not sure what you are getting at Tommy, ( I think in pictures) but could you two hole all your new stuff and use socket flanges to mate to their oddball stuff? Bolt up the sockets to their stuff, tack them good then take it loose and weld them? Or am I not understanding?
Parent - By DaveBoyer (*****) Date 01-29-2011 02:11
This sounds like it will be a bit_h. You can only hope the flange faces are square to the pipe axis, since they aparently didn't orient the flange holes.

I take it You don't have the option of removing the existing parts to replicate them...

Or You can't tack in place & remove for welding...

Do they make un-drilled flanges to be drilled in place?

I don't think a magnetic compass will work reliably, close to ferrous pipe.

You need a flat plane roughly parallel to the pipe to measure from. Can You temporaryly but firmly mount a flat plate behind and below the bottom flange and project a beam from a laser level up past both flanges and measure from the bolt hole C/L to the beam and compair differences? This might work if there is nothing in the way.

I am interested in how this is done as well.
Parent - By dbigkahunna (****) Date 01-29-2011 02:57
Can you use slip on flanges or RFWN required?
Parent - By swsweld (****) Date 01-29-2011 03:12 Edited 01-29-2011 03:16
Tommy,
Is it possible to find the top dead center of the horizontal pipe in two locations and then use a laser level similar to the one in the link to shoot (you said pipe was too long to shoot a line not sure if you were referring to a laser line level or another means)a line on the horizontal pipe onto the vertical pipe up to the flange and then you can "map" the bolt hole to the center of the 90 when you fab the new spool? If no laser level is available or not feasible for other reasons, soapstone lines on the top of the horizontal pipe and plumb bob from the flange will work too.

I tend to wait on pre fabbing situations like these if any way possible. If you DO get the hole orientation to work...the mating service might not mate up i.e. if you square your flange to pipe, you can't be sure they squared their flange to pipe when they fabbed it, especially since they didn't follow the basic two hole rule.

http://www.lowes.com/SearchCatalogDisplay?storeId=10151&langId=-1&catalogId=10051&N=0&newSearch=true&Ntt=laser+level

Similar to the Bosch near the bottom left in the link. 199.00

I too hope I understood your dilemma correctly.
Good luck......sometimes it's better to be lucky than good :)
Parent - By gndchuck (**) Date 01-29-2011 14:16
You might want to consider a swivel flange if it would be allowed.  It's thicker (i.e. longer), but it does rotate after it's welded.
Parent - By rcwelding (***) Date 01-29-2011 16:25
I have never done what you are talking about but I had two thoughts off the top of my head... Pull the old section and copy it or weld the new one in place just like they did the old one...

  Is that an option with ether one...??  I like using plumb bobs for complex fit ups sometimes.. They will hang still and let you pull measurements to your string... That was my only beef with lasers on vertical fit ups... Its hard to pull off of a laser..

   This info maybe useless but it was the two the two thoughts that came to mind right away..

   Good luck..!!

    RC
Parent - - By rcwelding (***) Date 01-30-2011 18:39
Tommy post some picturs of this Devil... I'm curious to see it..!!

RC
Parent - By Tommyjoking (****) Date 01-31-2011 03:09
Richard if I do the job I will try to snap some....I have not gave them a bid yet.
- By joe pirie (***) Date 01-29-2011 02:26
flange wizard makes an adjustable pocket level where you can put the level on the studs of the original
flange bolts adjust the vial to as is level read the deg on the face of level  , make your replacement
pipe offsetting the holes on flanges to match the deg on the level.
- - By boiler tube (*) Date 01-29-2011 02:45
Tommy, what I have done in the past is I set up my pls laser level that shoots a vertical beam. set it so that the laser beam is centered on the vertical pipe and under the throat of the elbow. that will give you a reference point for the pipe. If you have center head for a combo square you use that to mark a line between two bolt hole on the flange back to pipe. the center line on the flange and the center mark on the pipe from the laser will tell you how much to have to rotate your flange. I hope you can understand this and that it helps you out

Ray
Parent - - By Tommyjoking (****) Date 01-29-2011 18:01 Edited 01-29-2011 18:05
I was thinking about the laser, it seems like the best option, providing the face of the flange is square to the pipe.  Does anyone make a laser that shoots out both ends with like a magnet on it?  I could just put something like that on the pipe, shoot to the edge of a hole on one flange and measure the diff on the other.

The deal is the bottom flange is under a catwalk beside a containment dike against the building,  a 3 foot reach from the catwalk.  The top flange is in a pump shed about 2" off the floor but the pump house and equipment in the way make it about a 4 foot reach from the weld side and almost blind (underneath).   Someone along the line instead of fixing a broken mount on the top catwalk they decided to weld a 3 foot piece of angle to the pipe and it has rusted out, they do not want to put in a splice they want to replace all of it.   

I have just realized that I will have to cut the bottom catwalk, nobody could reach in there to bolt it up without doing that anyway.  I am being brain dead, it has been a long week!!!  I was modifying and fitting tanks yesterday and getting asked a million questions while I was doing it. I will weld the top flange get it up there and bolt it, I will cut some stairs out of the bottom catwalk and crawl way back there and get the bottom flange on, it is just real nasty in there lots of spills...I will try to get them to pressurewash that crap out beforehand.

I really appreciate all yall jumping in with replies!  Good help and it lets me know I was not being just stupid about trying to fit it.

THX
Tommy

I have never seen the pipe flanges that can rotate after welding, that would be appropriate in a situation like this.
Parent - - By boiler tube (*) Date 01-29-2011 22:49
Tommy, I have a pls laser model 180 that comes in a case with magnetic bracket that screws to the base thats great for sticking to pipe or columns. These units are a little pricey
but the are very rugged and will pay for themselves very quickly. PLS (pacific laser systems) has a very good web site that shows all their models and capabilities. Good Luck
Parent - - By Superflux (****) Date 01-29-2011 23:33 Edited 01-30-2011 01:33
Stringlines, piano wire and plumb bobs are far more trustworthy than lasers. Seen too many pipefitters (some of them true journeymen, not just newbie wannabes) screw up situations like the one you are dealing with by trusting a laser. If you have a vertical run, replacing a double flanged straight piece in the middle, clamp a straight edge on each existing flange on 2 hole. Drop 2 plumb bobs down and use a protractor of some sort (a drywaller's adjustable "T" square is a bit over sized and clumsy, but works great) to find the angle of adjustment in the mismatched 2 hole. This method (allows one craftsman instead of 2 to do the job), will also let you know if the 2 end points are out of plumb with each other rather than trusting the bubble on a regular level or laser level.

I think any true journeyman should be able to replicate the layout of the Great Pyramid's accuracy given enough string and slaves at their disposal.

DISCLAIMER!   There are laser devices that albeit trustworthy, are price prohibitive for most of us to buy or wish to have clanging around in a welding rig.
I am a non attorney pipefitter spokesman and I stand behind the aforementioned layout process and statements.
Parent - - By Tommyjoking (****) Date 01-30-2011 01:53
AHA!   moment for me

I also never thought about running two plumb bobs!  I seriously doubt the pipe is true...the double plumb bob takes care of that issue....simple straightforward and effective.   I knew there was a "Flinstone" method somewhere!   There is so much crap in the way between the two flanges I do not know if you could run a stringline all the way, but I will not forget the idea of it.

I use string all the time in shop to bring rails and such into true before welding, a roll of kite string sometimes is the most valuable tool in the box.
Parent - - By Superflux (****) Date 01-30-2011 05:31 Edited 01-30-2011 05:40
Occam's Razor paraphrased
"If the hi tech doohickies don't work...K.I.S.S."
Easier said than realized in the heat of the moment of course.
Parent - By rig welder6 (**) Date 01-30-2011 18:15
can u use a angle finder set on a set of 2hole pins to find the angle that they r @ and then plumb bob dwn to find if they are sq? jst a idea
Parent - - By ibeweldingsum (***) Date 02-16-2011 22:56
I'd have to see the pipe and where it's hanging to give a good answer, but here goes, if you have some kind of structure the pipe is mounted to, or hanging from, the best method I've used is measuring from the structure to the two most outer holes and transfering that difference to the flange I'm fitting on the ground using a level to measure off of to transfer the difference. Assuming the pipe you are installing is square plumb and level to the structure it is hanging from.
Parent - By Tommyjoking (****) Date 02-17-2011 00:29
It is a moot point now Matt  I do not think they dug my bid...I went by there a few days ago and I saw the pipe had been removed but not replaced yet.
Parent - By boiler tube (*) Date 01-31-2011 02:44
I use stringlines, plumb bobs alot of the time, but sometime lasers have been a great help also if you know HOW to use them. If you buy a cheap habor freight model you get what you pay for! I think any smart journeyman would use a tool that would make their job easier be it mechanical or electronic, each have their application.
Up Topic Welding Industry / Welding Fundamentals / Need help with Flange fitting

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