6 replies to this topic

[S Manikandan]

Good morning all,

 

I have a doubt in selection of scenarios for sizing PSV.

 

There is diesel storage system, which consists of a diesel storage tank, diesel pump and fuelling system. The diesel pumps transfer diesel from storage tank to fuelling station. Two diesel distribution filters (1W+1S) with a PSV in each filter, are placed at the pump discharge line. Please refer attached process flow diagram.

 

For sizing  PSV in the filter, Do I need to consider blocked in thermal expansion case or fire case? or both?

 

 

Please clarify my doubt.

 

Thanks in advance

 

Regards

S Manikandan

Attached Files

•  Process flow diagram.pdf   50.15KB   95 downloads

[fallah]

Hi,

 

At first please specify pump discharge pressure corresponding to the pump minimum flow in blocked discharge conditions. Also specify the design pressure of the filters.

[Fakhri]

Hi Manikandan,

In my opinion, you only need to consider the thermal expansion case due to shut-in conditions. The fire case is not valid scenario since the flash point of diesel is higher than the ambient temperature. This will not be able to form flamable vapour if it is released

 

Rgds,

 

 

Fakhri

[S Manikandan]

Dear Mr.Fallah,

 

The discharge pressure of the pump corresponding to the Min. flow is 6 barg

and design pressure of the filters is 10 barg, which is equal to the PSV set pressure.

 

Thanks and Regards

S Manikandan

[fallah]

Dear S.Manikandan,

 

Then the blocked outlet case can't be a credible scenario for mentioned PSVs. The only credible scenario can over pressure the filters more than 10 barg would be fire case provided that the filters are located in a fire zone and lower than the height of 7.6 m from grade ... 

Edited by fallah, 12 January 2015 - 03:33 AM.

[S Manikandan]

Thanks to Mr.Fallah and Mr.Fakhri for your replies.

 

 Thanks and Regards

S Manikandan

[Hamid_r_2003]

as far as I know for such system which is full of liquid you just need a TSV for thermal expansion.