Dear all,

Please clarify the following,

Suppose we are connecting one line from boiler teriminal to Turbine, I want to check the nozzle load with Turbine manufacturer allowable nozzle loads.

Hw can I do that? either putting an anchor at the point(Nozzle connecting point)and checking the restraint summary or can we check with global element forces at that point(without specifying as anchor).

Thanks in advance.

venk

A boundary condition like displacement or an anchor should be specified. Restraint summary to be used for finding the actual loads or reactions.

Dear Venk,

1)Define anchor at turbine nozzle connection node.
2)Define displacement at this anchor node provided by the vendor on turbine data sheet.
3)Compare caesar restraints loads on this node with the manufacturer nozzle allowables.
4)Check alignment.

Regards,
Aslam

If you define displacements, you don't need to define the anchor. They are (both) essentially the same thing - a boundary condition. An anchor is the same as a set of six displacements with "zero" magnitudes.

Oops.........Thanks Richards,

My second point is making a different sense.
I intended to say from point 1 and point 2 that define a anchor with displacement using Cnode.
Please combine first two points accordingly.

Regards,
Aslam

I think the reason for the ANC is to get the values of forces and moments from that point.

In case the displacement given, you still need to match the piping loads of yours at the terminal point to the opposite side loads.

In case the anchor specified at the terminal point, the anchor design shoud consider both side of the loads.

I would offer a terminal point that has a line stopper with/without vertical (rigid or spring) support in normal application and add a couple more support from the other side of the piping into my analysis and watch the piping deflections and loads at supports to meet the opposite side results. This may require aggreement of both sides and their analyses.

This approach may take some more time in the analyses but reduces the support costs at the terminal point a lot especially on the high temperature steam lines.

Hope it helps

Ibrahim Demir

HI EVERYBODY,

CAN ANYONE TELL ME HOW CAESAR-II FINDS THE COMPONENTS OF THE MOMENTS OF THE INLET /EXTARCTION NOZZLE, AT THE RESOLUTION POINT AND HOW THE RESOLUTION POINT CAN BE CALCULATED, BECAUSE AS PER NEMA SM 23, IT IS NOT CLEAR TO ME HOW TO FIND OUT THE RESOLUTION POINT. I RAISED THIS QUERY BECAUSE I TRIED TO CALCULATE MANUALLY AS PER NEMA SM 23 AND AFTER THAT, WHEN CROSS CHECKED WITH CAESAR-II, THERE WERE DIFFERNCES IN CASE OF MOMENTS.

The forces and moments on the steam turbine connections are to be resolved about the intersection of the centerline of the turbine exhaust and the centerline of the turbine shaft.

What is the resolution point if the centerline of the turbine exhaust and the centerline of the turbine shaft are different in elevation?
Thanks

This case is not directly addressed by NEMA-SM23. Our correspondance with NEMA on this issue indicates that you should contact NEMA directly with this question.

It is good policy, particularly when dealing with a compressor under (factor)x NEMA SM-23 to always agree the resolution point with the machine vendor.

Also, the basis for calculation of factor Dc, the equivalent opening should be agreed since it affects allowables. It may be based on the nominal or inside diamenter for instance.