I have 36 inches HP steam line with design pressure 59.1 bar and max ope. temp 272 degC from vessel to suction of centrifugal pump-A and pump-B. Client saying that the flange face of piping miss-alligned in the one side of pump when it is operated. Miss-allignment in upward direction (around 3mm) started when pump still in the warm-up temperature (around half of max operating temp).

In order to have a clear idea to what is the possible solution for above problem, my understanding in term of modeling in Caesar is by modeling all the actual condition including miss-alligned in the flange face and check the behavior of pipe.

Please throw some light on and share your valuable the best way to solve miss-alignment in Caesar. How about load case that address to misalignment issue? I know that WNC might be used but it is during installation whereas current miss-allignment when under operating condition (warm up temp).

thanks
piper

Is your load cases with one pump idle/one pump running, and both pumps running. Can you post a sketch/drawing or jpg model of your work?

there are two pump with running-stand by case. Load case for pump running -stand by has done: all hot, hot-cold and cold-hot. I'm wondering is there any other load case that need to be considered to address miss-alignment pump under warm-up until operating since the client having a such problem.

Attached is the sketched drawn through paint tools. There are two variable springs support installed for each pump line but quite far from the suction nozzle. The story is that the pipe pushing in the downward direction pushing the based elbow support and then enogh to make the line pipe that connect to suction pump skewed/bulk in upward until the end of the pipe (in this case flange facing to the suction nozzle). The client finally cut the based elbow support hence there is a gap to allow pipe pushing in downward direction hence avoiding.

I checked based on normal analysis with all hot, hot cold and cold hot, everthing seems fine in term of the displacement of the pipe and the load acting also in the downward. I'm wondering the spring still weak hence transfer significant force to the based support.

thx
piper

I don't understand the term "misalignment".Generally, misalignment or rather alignment is checked during installation of pump to avoid undue forces which may occur if the alignment is not proper.Do you mean "thermal displacement" by Mis-alignment?

Because had misalignment occur at pump-piping mating flange during operation, there would be significant leakage at nozzle junction.

Can you elaborate the whole scenario to understand the real problem?

Hi Appleapple,

I quoted part of your first post "...by modeling all the actual condition including miss-alligned in the flange face and check the behavior of pipe". Do you mean the "terminal/anchor point displacement input values" of pump nozzle and piping connection if you did not model the equipment? I am a bit confused between the 3mm "Miss-allignment" in upward direction (around 3mm); and the "miss-alligned" term you modeled? As SJ said, the term alignment of pump nozzle to mating flange of piping is done during installation when the system is at ambient temp.