Posted by: anindya stress
SURGE LOAD - 10/12/07 02:38 PM
I have a problem where a piping system is modelled and the effect of surge
due to pressure differential across elbow pairs is investigated.
The major pressure differential is existing between the elbows ( an example
) 10 and 20 where my pipe between the elbows is in Z direction. After
elbow 20, the next elbow is 30 where the pipe between the elbows is in X
direction. and length and differential pressure between elbows 20 and 30 is
much less than what is between 10 and 20.
My question is: Should the surge load on elbow 20 be equal to the pressure
differential between elbows 10 and 20 times the flow area , acting in Z
direction only or in both X and Z?
As per my understanding, under the action of pressure on elbow , the
loading should be in two directions, at the two weld points. However the
portion of pipe which is between elbows 10 and 20 is in Z direction and
the max. differential is between these two elbows . The distance between
elbow 20 and 30 is very less ( in comparsion to that between 10 and 20) and
the pipe is in X drection between these elbows and the unbalanced load in
20 in X direction should be balanced by that in 30 in X direction ( because
of small distance and small differential between them) and hence the
effective unbalanced force at 20 will be in Z only.
Would like comments on the above.
Regards