PIPING STRESS ANALYSIS SUPERHEATED STEAM LINE

i NEED HELP FROM ANY EXPERT IN THIS FIELD.
i AM WORKING ON A HIGH TEMP / PRESS. SUPERHEATED STEAM LINE. (TEMP 950 DEG F, PRESSURE 950 PSIG)
OR IN ALTERNATE UNIT. (500DEG C / 65 BARG). I NEED ADVISE AS HOW TO PROCEED AHEAD. I M TRYING THE ANALYSIS ON CAESAR II / ALGOR BUT THE MODEL KEEP ON FAILING. ALSO ADVISE ME WHETHER I CAN USE EXPANSION JOINT FOR SUCH HIGH RATING OR ELSE I HAVE TO USE LOOPS.
THE PIPING IS FROM BOILER TO TURBINE AND DESUPERHEATER. THE STEAM OUTLET OF BOILER IS AT 16M HEIGHT FROM THE HEADER WHICH IS AT GROUND LEVEL. I HV TO ENCOUNTER VARIOUS PIPE LENGHTS WHICH ARE 6M, 7M, EVEN 11M. AS PER CAESAR II OUTPUT FILE MAX DEFLECTION IS COMING IN A RANGE OF 3''.

THANKS IN ADVANCE

AQEEL

In the limited span that I have had with piping, I did not see Expansion Joints being used (at least) in this case. They were mostly used at large tanks to counter tank-settlement. 3D Loops is your best bet I will say.

This is a two way job aqeel78..!
Look at the layout sitting together with the layout engineer & discuss if we can have some expansion loops to make this line (system) safe.

Your first preference should be always a Expansion loop & if layout point of view if it is not at all possible then & then only you should think of expansion joint.

Dear All,

Many thanks for your replies.

The big queston for me is "whether expansion joint is manufactured in this range or not i.e 500 deg C and 65 barg (1000psi) simultaneously. I hv already contacted many suppliers around the world, but so far no reply in yes. They are supplying in lower ranges. If for example it is not produced in this range then i will have to settle for loops. Obviously my first choice will be loops.

Second thing is how to tackle expansion in vertivcal pipe segments. for example the boiler outlet is at 16m height (53 ft) and header is at ground level. i have broken that length into two segments (5m and 11m) by using a horizontal segment in between. Can i give loop in vertical pipe segment.

Also in entering fluid density in CAESAR II software (if i wanted to take specific gravity should i compare superheated steam density with air or with water.

Best Regards,

Aqeel

Dear Shrivallabha,

"3D Loops is your best bet I will say."

What do you mean by 3D loops.

JOP, I agree to your definition and I hope that I've not caused any confusion.
My Definition:
2D Loop : Flat Loop (Co - planar geometry)
3D Loop : Change in direction and plane.

As to AQEEL's query:
You can use loop in vertical as well given that you plan your supporting well.