Dear all,

i M trying nozzle check option in caesar but i have lots of confusion.

If My nozzle orientation is in west direction and pump shaft is also same orientaion then what will be reff vector?

if i define reff vector as (0,1,0)then result are matching except sigh of load in west derection is opposite to the restraints summary so please clearify why is error?

I must assume that you are using "read from file" to fill the load limits for the directions A, B & C. I will guess you are using the API610 data. This data is held in the SYSTEM in the file API-610.eql. That file defines the translation from the API 610 coordinates x,y,z to the CAESAR II coordinates A,B,C for each of the three nozzle orientations - Top, Side & End.
For Top nozzles: B is shaft orientation
For Side and End nozzles: B is up

I am uncertain of your sign issue. But signs are not significant in this evaluation. The check is on the magnitude (i.e., using the absolute value) and there is no nozzle combination check (as in API 610 Annex F).

Dear Dave,

Thanks for your quick response.

As you told i have taken one case study in which i have considered end suction - top discharge pump.
nozzle is 3" suction.
configuratin and input for nozzle limit check as per Attachment-1.
But output of this nozzle limit check is ok.but sign asigned to Fa,Fb,Fc, that i didn't understand how they came?

i compared Fa,Fb,Fc sign with local forces (applying righthand rule) but still at lest one force sign is not matchig with that please find the attachment of output (Attachment-2).

Dave,I think sign of these forces are important for better judgemnt while analysis.

Thanks,

Your A axis is negative Z, your B axis is positive Y. The C axis is, then, positive X.

Reviewing your nozzle check using your load case 1...
Restraint report shows the following loads:
X:- Y:+ Z:-
Nozzle check shows these loads:
A:+ (use negative Z load): correct
B:+ (use positive Y load): correct
C:- (use positive X load): correct

Looks good to me.

Remember that your pipe is entered in the -Z direction so A is -Z.

as per restraints it is Y:+ so it is in upward direction.

but as per nozzle check B:+ so as per local forces direction it is in Downward direction.

so please explain how to undersatand nozzle check output?

-The load is positive Y.
-The B axis is defined as positive Y.
-So the B load is positive.
I don't know what needs explaining.

Does this help?...
If I redefine your reference vector (B) as negative Y (0,-1,0):
-The load is positive Y.
-The B axis is defined as negative Y.
-So the B load is negative.