1 reply to this topic

[avskaushikchemical]

Hi all,

 

I have a vessel (reflux drum) which is operating at a pressure of 14 kg/cm2 g with corrosive vapors (HCl) and hydrocarbons service and is provided with pilot operated PSV. The discharge of PSV is floating on a column operating at a pressure of 12 kg/cm2g. It is a reflux drum to a stabilizer column. Sensing line of the PSV was taken from overhead of the stabilizer column. As pilot PSV inlet seats were continuously getting damaged due to corrosive vapors from the vessel,we proposed to put a rupture disk upstream of this PSV. Burst pressure of rupture disk and set pressure of PSV are same as 17 kg/cm2g. 

 

The question is whether a rupture disk + pilot PSV combination can be used as per API guidelines?

 

In such cases, from where should be the sensing line of pilot PSV be taken from? If sensing line is taken from column overhead, then anyway the pilot PSV is getting exposed to corrosive vapors which means the purpose of rupture disk is getting lost. If sensing line is taken from inlet of pilot PSV (after rupture disk), then there will be no pressure on pilot and PSV will be open.

 

I am confused on this arrangement.

 

Please guide in this regard and examples if any of this arrangement will be helpful.

 

Thanks

[breizh]

https://rccostello.c...systems-flares/

 

Hi,

If you install a rupture disk you need to change the type of PSV  .

 

Consider the link underneath .

https://www.eng-tips....cfm?qid=234150

 

My understanding 

Breizh 

Edited by breizh, 24 January 2021 - 03:21 AM.