3 replies to this topic

[Arsal]

Following relief data are available in Lb/hr from different unit from refinery, All these PSVs are relieving in common flare.

 

UNIT 1:

PSV 01 (power failure case) : 129000

PSV 02 (power failure case) : 59000

PSV 03 (fire case)                 : 60000

PSV 04  (fire case)               : 25000

PSV 05  (blocked outlet)          : 85000

PSV 06  ((fire case): 2000

 

UNIT 2: 

PSV 01 (fire case) : 45000

PSV 02 (fire case) : 29000

PSV 03 (fire case) : 15000

 

UNIT 3: 

PSV 01 (Blocked Outlet) : 45000

PSV 02 (air cooler failure) : 29000

PSV 03 (Blocked Outlet) : 15000

PSV 04  (fire case): 35000

 

How we calculate the relief load for flare header or flare stack? or how we can set design flow rate for stack or flare header?

Edited by Arsal, 03 October 2016 - 04:57 AM.

[fallah]

Arsal,

 

At first it's strongly recommended an flare design expert to do such important job; anyway in brief:

 

Suppose the mentioned info to be relief load of governing case for each PSV, the relief load of each PSV for the scenarios other than governing case should be specified. Then comparing the total relief loads of common and single failures the highest total relief load should be considered as a basis for flare header design...

[Arsal]

Thank you very much for your value able comments. i am just asking for my information.

 

Could you please tell me how much back pressure or pressure drop will increase if Liquid seal drum will be added in the system. Furthermore, what is the limit of Sterile radius for flare.?

[Arsal]

Yes all above mentioned values are form the governing case of the PSVs.