Fire Case Protection for process pipes/pipelines

[david6245]

Hello All,

A colleague and I are having a discussion on the overpressure scenario(s) that must be considered for process piping/pipelines. Would the cases differ from any of those we consider for pressure vessels, i.e. blocked outlet, fire, thermal expansion, etc? The reason I ask is that we have not seen many pipes with relief devices other than those providing protection from thermal expansion.

Our question is: if fire is a credible scenario in the area where the piping is, should the piping be fitted with a PSV that can handle the load from an external fire?

Thank you,

 

[jamesbanda]

My view is that it is unlikely.
> Most pipe are connected to vessels that have relief valves.
> long lines on racks are very unlikely to have fires under the racks becuase these are no vessels with sufficient volume to cuase a fire sufficient to over pressure.

 

[dcasto]

I add about 10% capacity to my vessel relief scerios to cover lines in and out. If you have a line that can be isolated automatically or as part of a failure scenerio, then yes, you should have a fire case relief valve. The valve will most like size out the same as just a solar relief scenerio.

If the line can be blocked in manually, then I use administrative controls that lower the pressure or drain the line when 100% isolated.

 

[CJKruger]

Pipes are usually protected by relief valves on the equipment that these pipes are connected to.

If fire is the only case for the pipe, then you can (and often have) a block valve in this circuit, and it does not need to be locked open (AMSE App M5.8).