Hi
I am doing analysis of Boiler Drain Line.
But i have scope near by a Flushing tank..
at the teminal point of this piping i have to give forces and moments to Boiler vendor.( for His piping)

But which type of Boundary condition i should apply at this teminal point to get the forces and Moments.

I am using Anchor with Cnode.
Is it a right way to model this Boundary condition ?

Thanks
Aditya Singh

You need to look at the geometry of the equipment you are connected to. Most likely, that nozzle that you are hooking up to is going to have displacements that you will need to consider in your Caesar model.

This can be accounted for a couple of ways. My preference is to build a model of rigid elements from the fixed point of the equipment to the flange face considering the appropriate temperature of the equipment and let Caesar determine the movements for you.

One other thing to keep in mind, since you are talking about a drain line, is that your worst case may be to have your line at ambient and your equipment up to the block valve at operating temperature dragging your pipe around.

Thanks Edward,

Actually i think, I could nt explain my question clearly.

My scope of analysis ends at particular area, afterword the scope of analysis is of different agency.
We have provide them Force/ Moments & Displacements at my terminal point.

How can i get Forces/Momnets/displacement at the terminal point.
Which type of Boundary condition one has to use ?

Thanks
Aditya

post both anchor and Fx FY FZ conditions and let them pick what they want to use....

Based on my follow up, my recommendation remains pretty much the same.

Understand, you are talking about an arbitrary point in space for your contractual break. The reality is the pipe doesn't care whose package it's in. The forces/moments and displacements at a given point are going to depend on what going on with both sides.

If your side is much stiffer, then displacements will tend to be governed by your piping. Alternatively, if the other vendor has a stiffer system, such as a direct nozzle connection on some sizable equipment, then it is likely going to push your pipe where it wants to.

You still need some idea of what is going on across the border. If you have piping runs on both sides, your best bet may be to meet with the vendor and agree to an anchor point, either on your side or theirs. A reasonable stiff anchor allows each side to work fairly independently of each other.

dear john
can you plz explain in detail.

Dear Adi,
Although It's difficult to suggest something without knowing the details, you can consider the following.

1.When so may things are unkown on the other side your best bet may be to design an anchor very close to the battery limit. Better in the straight portion of piping connecting to your vendor. This will safeguard your piping from the bending moments imposed from the other side.

2. Calculate the anchor loads (Fx, Fy, Fz and Mx, My, Mz) from your analysis. See that they are reasonable.If your drain lines are small these will not be very high. Give double of these loads to your structural team to design the support.(This will take care of the loads from the other side.)

3. Give your anchor location to the boiler vendor. Also give them allowable loads( Half of what you gave to structural).They can include the remaining portion of pipe in their analysis.

4. However, the best way is to get the details of their piping and anchor points. Analayze the whole system as one . You can avoid providing any anchors . You can also avoid providing unnecessary flexibility which may be required if you provide an anchor.

Regards
Siv

aditya singh...

The two solutions will supply different answers but will encompass the min and max loads i.e. forces and moments.... structural members designed using these values will be "safely" designed.

Try a simple model using the two end fixities and you will see what I mean.