PIPE ELBOW DIMENSIONS ,

[pdprao]

S.S PIPE ELBOW TO ASA B16.9 SCH 40. 10INCH , SIZE IS ORDERD

WHAT IS SUPPOSED TO BE THE DIMENSIONS OF THE ELBOW AT SAY 45 DEGREE POSITION IN CASE OF 90 DEGREE ELBOW?
1) WHETHER THE SUPPLIER CAN GIVE A FITTING WITH OD 12 MM LESS ( AS COMPUTED BY CIRCUMFRENCE MEASURED AT45DEGREE POSITION)?. BUT THE WELDING ENDS ARE FLARED AND BROUGHT TO MATCH WITH REQUIRED DIMENSIONS AS PER B16.9 REQUIREMENTS TO MATCH WITH 10 INCH SCH 40..
2) WHAT THICNESS AT 45 DEGREE POSITON OF 90 DEGREE ELOBW CAN BE SUPPLIED?. WHETHER IT IS TO BE WITH IN THE BAND OF NOMONAL (SCH 40)AND NOMINAL MINUS 12.5 % OF WALL THICNESS.,?. OR THE THICKNESS IS LEFT TO THE MANUFACURER OPTION TO MEET THE DESIGN AND TESTING REQUIREMENTS AS PER ELBOW DESIGN. IN THAT CASE THE THE THICKNESS WILL NOT BE LISTED THICKNESS AS PER ASA 16.9 EXCEPT AT ENDS. FOR FLEXIBILITY ANALYSIS THICKNESS AT THIS POINT IS IMPORANT, HIGHER THICKNESS IS UNDESIRABLE WHICH RESULTS IN HIGHER NOZZOLE LOADING
3) IS THERE ANY I.D DIMENSION THAT IS SPECFIED IN STANDARDS WHICH NEED TO BE SATISFIED FOR INSPECTION CHECH AT SAY 45 DEGREE POSITION FOR ACCEPTANCE ELBOW?. OR THE MANUFACTURERCAN GIVE ANY THICKNESS AND ID ?. THE ISSUE IS NOT OVALITY BUT OD,ID, WALL THICNESS AT 45 DEGREE POSITION.

COMMENTS ARE INVITED ON THIS ISSUE

 

[zdas04]

pdprao,
Many of us have a very difficult time reading all caps. Old eyes need the differentiation of mixed case and punctuation. Also, in the current internet etiquette, all caps indicates SHOUTING.

Most of the time 90-degree elbow dimensions are given from the face of one flange to the centerline of the other. For a long-radius, 10 inch, schedule 40 flange this "A" dimension is 15 inches.

For a 45 degree fitting it is a bit more complex. Draw a line from the centerline of each outlet concentric with the outlet piping. Where these lines intersect is the "B" dimension. For the fitting you have specified the "B" dimension is 6.25 inches.

My experience has been that fitting manufacturers are both flexible and inflexible at the same time. They are under incredible competitive pressure to keep costs to an absolute minimum so their processes are highly automated with extensive jigs and fixtures for the manual processes. Standard fittings are made to very close tolerances and it has been my experience that the consistency from any of the major manufacturers is outstanding.

On the other hand, if your project can pay the price, most of the manufacturers have lab equipment that can make one-off parts for a pretty high price and generally a pretty long lead time.

Just out of curiosity, why do you want to reduce the OD from 10.625 inches to 10.466 inches? If it is an experiment you might try getting a schedule 160 elbow and having a machine shop thin the ends.

David Simpson, PE
MuleShoe Engineering

http://www.muleshoe-eng.com

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

The Plural of "anecdote" is not "data"

 

[pdprao]

Well zdas o4, thanks for ur reply . Your point is taken care regrding lettering etc.
The problem is not about flanged elbows. Ofcourse your comments about dinensions are still valied.
We have recived fittings with less od (12mm) , higher thickness , ends flared to suit standard end od dimensions. Fittings are shipped after inspection by internationally reputed third party inspection agency. The supplier claims the fittings are as per standards.
we need to cut 90 degree elbows in to 45degree , and others cut to suit degrees. The joints areE.B. insert joints with 100% radiography reuirements.
Can we reject these elbows and ask for proper fittings?