PSV Vent To Atmosphere

[all2win]

Hi Everyone,

Some of the PSV's vents provided in Distillation Towers are routed to Atmosphere (if they pop up), not to flare as done normally. This is the case in most of Lighter hydrocarbons handling equipments like in Deethaniser and Ethylene tower. why cant we put them into flare? .IS there any specific reason behind it ?

Your Opinions Plz.

thanx

 

[jte]

Check local environmental regulations. I believe that in the area I'm familiar with if any of the PSV's on top of the atmospheric or vacuum columns ever actually pops (I'm told that's nearly impossible) then the PSV's would have to be routed to the flare. In essence their venting to the atmosphere was grandfathered in as long as they "behave".

jt

 

[dcasto]

Money? The flare will operate at 100 F in the day and when the PSV opens it will be -121 F. Metallurgy, expansion loops, diameter, huge diameters, segragated cryogenic (water free) flare headers, and other issues (?) .......

Ethane is not a regualated VOC, I'm not sure about ethylene. So that is not always a factor

Finally, These products will disperse and not become a fire safety issue unless the outside temperature was really cold and the don't vaporize.

 

[all2win]

thanx for your inputs