RE: High temperature Piping in Refineries

a good reading here is from a paper submitted by LC Peng during the HP Equipment Reliability Conference. The paper discuss pitfalls and misunderstanding related to flexibility analysis of piping connected to rotating equipment.

According to LC Peng.
Too much flexibility in a piping system is not desirable since it will have difficulty in meeting the stringent allowable load imposed by the equipment (he's of course refering to the nozzle allowable loads per API 610 for centrifugal pump, API 617 for compressor and NEMA SM 23 for steam tubrine).

The use of expansion loop makes the pipe prone to vibration since it will get easily excited by a small disturbing fluid force (normally we term this as focring function in vibration). In addtion it enhances the internal fluid diturbenace by creating cavities due to excessive delta P.

> ----------
> From: Macharla, Hari[SMTP:HMacharla@mcdermott.com]
> Subject: [PipingDesign] High temperature Piping in Refineries
>
> Hi All,
> Pump suction lines are
> provided with many loops to take care of flexibility. This is not good for
> equipment performance..what machinery experts say. Ofcourse plants are
> running.
> Please share your expereinces and help in enrich the knowledge of other
> members.
> Regards.
> Hari Prasad Macharla
>
>
>
Received on Sat Sep 29 04:45:00 2001