Stress analysis of Jacketed Piping
Stress analysis of Jacketed Piping
(OP)
Greetings Friends,
Can anyone brief me on the basics of doing stress analysis for the Jacketed Piping system . What are the considerations ?
Can anyone brief me on the basics of doing stress analysis for the Jacketed Piping system . What are the considerations ?





RE: Stress analysis of Jacketed Piping
RE: Stress analysis of Jacketed Piping
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Stress analysis of Jacketed Piping
With permission, post this in the COADE Inc.: CAESAR II forum.
The other thing that I typically do is double the corrosion allowance for the inner pipe, since it is exposed to (admittedly different) process fluids on both sides of the wall. This exacerbates the concern raised by BigInch. However, I usually see the hot fluid on the jacket side (e.g., sulphur) and the warm-up procedures typically require the jacket fluid to come up to temperature first, so for me, usually the core pipe is in tension.
Regards,
SNORGY.
RE: Stress analysis of Jacketed Piping
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Stress analysis of Jacketed Piping
The guy asked about stress analysis of ... I still say, put it in the hands of an expert.
RE: Stress analysis of Jacketed Piping
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Stress analysis of Jacketed Piping
Jacketed Pipe
Jacketed piping systems are input by running the jacket elements directly on top of the core elements where the two are concentric.
A very simple way to generate a jacketed pipe model is to run through the entire core and then duplicate the core piping using a proper node increment (such as 1000). This will produce a second run of pipe, which will be modified to build the jacket model. For the jacket, change the pipe size, temperature; bend radii, etc., to finish the model. Then attach the jacket and core by changing the node numbers and adding restraints.
Typically, the end caps connecting the core to the jacket pipe are much stiffer than either the core or the jacket. For this reason node pairs like (10 and 1010), (25 and 1025), (35 and 1035), and (40 and 1040) are often joined by using the same node for each, i.e. the displacements and rotations at the end of the core pipe are assumed to be the same as the displacements and rotations at the end of the jacket pipe.
Internal spiders offer negligible resistance to bending and axial relative deformation. Node 15 might be connected to node 1015 via a restraint with connecting node. For an X run of pipe, rigid restraints would exist between the two nodes for the Y and Z degrees of freedom.
The +Y support acting on the jacket at node 1020 does not cause any stiffnesses to be inserted between 20 and 1020. Node 20 is included in the model so that outside diameter interference can be checked at the 20-1020 cross sections. Should there be any concern about interference, or interference-related stresses at the 20-1020 nodes, then restraints with connecting nodes and gaps can be used to approximate the pipe-inside-a-pipe with clearance geometry.
Since CAESAR II constructs the jacketed piping model by associating nodal degrees of freedom, the program really does not know one pipe is inside of another. Therefore the following items should be considered.
If both the jacket and the core are fluid-filled, the fluid density of the jacket must be reduced, to avoid excess (incorrect) weight.
If wind or wave loads are specified, the wind or wave loading must be deactivated for the core, or else the core will pick up wind load.
The core pipe should probably have its insulation thickness set to zero.
RE: Stress analysis of Jacketed Piping
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus