3 replies to this topic

[fallah]

Dear All

In designing flare system piping:
- what is the min. slope in main header and the subheaders and based on which references?
- what is the normal height difference between piperack on which flare header lied, and the knock-out drum inlet?

Regads

[JoeWong]

fallah,

- what is the min. slope in main header and the subheaders and based on which references?

I have seen 1:500 for both on one project and 1:200 for sub-header and 1:500 for main header for another project.

- what is the normal height difference between piperack on which flare header lied, and the knock-out drum inlet?

Other than optimum design maintaining free draining slope towards KO drum and no low pocket, i can't think any requirement on height difference...

If you got any special advice/requirement by other, let forum know...



JoeWong

[fallah]

Dear joe wong
Thanks a lot for your reply,but:
-What is the reference for slope other than API 521?
-Can we use CAN type pump for extracting liquid from KO-drum due to shortage of NPSH(by considering a sump under KO-drum)?
Note that all submitted questions are in the field of FLARE SYSTEM in Natural Gas Treatment Plant, and any other comments will be highly appreciated.
Regards
N.Fallah

[JoeWong]

Dear joe wong
Thanks a lot for your reply,but:
-What is the reference for slope other than API 521?
-Can we use CAN type pump for extracting liquid from KO-drum due to shortage of NPSH(by considering a sump under KO-drum)?
Note that all submitted questions are in the field of FLARE SYSTEM in Natural Gas Treatment Plant, and any other comments will be highly appreciated.
Regards
N.Fallah

fallah,
It is not from API Std 521. As mentioned in earlier posts, "i have seen..." means it has been designed in certain way but no specific reference. It is experience and good design practice.

Yes. You may use CAN pump. But messy on maintenance.

JoeWong.