Hi to you all:

We are actually supporting a vertical rotating equipment with an agitator with an horizontal nozzle (size 28") with the following allowables:

P (N) Vc (N) Vl (N) MT (Nm) MC (Nm) ML (Nm)
Fz (N) Fx (N) Fy (N) Mz (Nm) Mx (Nm) My (Nm)
11000 8900 8900 13500 9100 9100

Diameter : 1100 mm
Weight = 225400 N
Friction forces = 22540 N (P in the table)

We want to hold it with hangers, and ONLY the friction forces we would get (not considered by CAESAR???) are already over the allowables given by vendor. is this correct? does CAESAR consider friction forces in hanger calculations?

Thanks to you all.

could you be more specific, i am confused as to the question,
soz,

the Yrod boundary considers the horizontal force induced by the swing in a hanger rod read the tech reference or search on this forum

I have had several people ask me about friction in spring stanchions lately. I will give you the same "answer" I give to them.

The load path for a spring stanchion goes through a coil spring. The coil spring has a clearance "x" with the ID of the can. The coil spring has a lateral stiffness that can be calculated. It also has a rotational stiffness about either of the two axes perpendicular to the load path, and that can also be calculated.

The load is connected to the spring by a compression rod of non-zero length, so the translational stiffness of the attachment point of the spring hanger can be calculated. (Don't ask me to explain; references are relatively easy to come by if you look.)

Until the spring comes into contact with the can at some point, there is no real mechanism for sliding friction. This is true because both the lateral stiffness and the rotational stiffness of the coil spring, when translated out to the load point, are much smaller than the product of the support load x the friction coefficient. So sliding friction for a spring stanchion is nonlinear - as soon as (but not before) the load point moves enough for the coil spring to make contact with the can, sliding friction becomes possible.

Thanks CraigB, but maybe I did not explain myself clearly.
I meant that the 28" pipe would make the rotative equipemt move horizontally for it is only holded by spring hangers LISEGA type 29xxxx and CAESAR seems not to consider the slidding of the equipment over the springs and its friction forces over the hangers.

Thanks again.

could you post a screen dump?

I hope, you can see the pic.

The equipment located above is fixed and the one below is resting over spring hangers (4)

thx,

erm,

By observation, i would be extremely wary about supporting this with a spring.

Springs are not happy in dynamic envornments, add this to your relativly stiff set up and i think you could be asking for trouble. Your nozzles will be seriously overstressed

I would think it much better to firmly support both vessels via anchors and either add flexibillity to the pipework or add a bellows.

sometimes, adding high detail to a model leads you down the wrong path.

Of course, i could be completly wrong as have no idea of your design but looking at the model would suggest the above.

Try rotating the 28" nozzle 90 deg hor.