5 replies to this topic

[David A.]

Hello All,

 

For relief header sizing and flare system design, does relief from manual blow down have any appreciable impact considering the fact that ideally manual blow down is not instantaneous.

 

I'd appreciate your expert  opinion on this. 

[AlertO]

Hi David

 

Normally your blowndown system is designed for blowdown from PSHH or design pressure and the flare system is according to this basis as well. Does your manual blowdown means blowing at operating condition? if yes, the flare system can handle with your scenario.

[David A.]

Thanks @AlertO for your swift response.

 

Currently I'm working on a gas handling facility project where the 3rd party consultant for the flare system is requesting for the maximum relief loads and other gas properties from the manual blow down valves for the flare header sizing. What if you are to blow down manually after an emergency shut down, does this still contribute to the determination of the flare system capacity.

[fallah]

Hi,

 

Blow down in order to depressurizing either to be done manually or automatically following to an emergency shut down has to be contributed to the determination of the flare network capacity...

[AlertO]

Dear david

 

The blowdown after emergency shutdown is always one of the design case for flare system capacity. After ESD you have to assume that your system is under the servere condition and the initial process pressure shall be at PSHH, design pressure or settling pressure (for compressor). This will give you the maximum flow for determining the capacity of the flare capacity.

 

However, the flare capacity maybe sized based other scenario i.e. PSV relieves due to fire,  electrical failure etc when the blowdown case isnot the governing case.

Edited by AlertO, 30 November 2014 - 08:45 PM.

[David A.]

Thanks Fallah and AlertO.