Vibration Line

Hi,
I am doing a stress analysis of an existing line (10" pipe) in which is getting vibrated. The line is connected to vertical equipment in which the equipment has a design temperature is 50 degree Celsius and the line has -101 degree Celsius. At a point on pipe support taken from the vessel, the pipe gets displaced up to 27 mm upwards on node 235. I have considered only guide support at node 235 in axis (X & Z). Here I am not considered rest support.

• Do I need to provide a spring support at that point node 235?

• If I provide the spring support on 235 node the piping system get vibrate or not.

Please provide vertica lsupport in your line first

shaily thanks for your reply.

Vertical support means rest or spring supports. If i provide simple rest support the support gets lift up by 27 mm and so the pipe support will not rest on the support.

If the vessel nozzle load is within limit, it is not required to add support at that point.
If the line is vibrating then do the Modal frequency check analysis and maintain the frequency of the line above 4Hz by adding guides and stops.
This might solve the problem of vibration.

Thanks Senthil for you quick reply,

We have also checked the modal analysis the output is more than 4Hz (vibration is solved as the new analysis). So my question is can I provide the spring support for 27 mm lift up case on this support node at 235 instead of guide support.

When I considered the guide support on this node at 235 the nozzle loads are within the allowable limit.

If I considered the spring support on 235 node, the spring support is advisable for vibration lines.

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Hi Kart,

The spring is colocated in vertical or horizontal axis?
I would tell you to try setting spring on 230 and guide on 235.

It is not only about the NOzzle load we talk in Stress Analysis.TO let your system perfectly balance you need to support the pipe for Dead weight conditions also,Please note line vibrates due to unsupported spans most of the times.

Kart: If you provide a rest support in the line ,make sure to connect it from the column itself , It will grow alongwith the column(27 mm as specified by you) and at the same time will support the pipe.

You can also provide spring support and check the analysis , retain the guide as it is .