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Balanced Bellows Relief Valve


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#1 farid.k

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Posted 20 May 2020 - 11:45 PM

Hye all..normally if total back pressure of relief valve less then 10% of setting pressure, conventional type will be selected. My question, is there any process or performance of relief valve impact is backpressure less than 10% but selecting balanced bellows type? i trust no issue other than cost wise will be expensive. balanced bellows total back pressure normally will be considered if total back pressure to its set pressure more than 10%.



#2 latexman

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Posted 21 May 2020 - 07:37 AM

A bellows can be used to keep debris/solids in the discharge away from the spring and moving parts.



#3 farid.k

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Posted 21 May 2020 - 08:12 AM

A bellows can be used to keep debris/solids in the discharge away from the spring and moving parts.


Thanks for the feedback. Any issue i.e. potential of chattering? I don't think so since it can tolerate more back pressure.

#4 latexman

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Posted 21 May 2020 - 01:17 PM

As you reasoned, less potential for chattering.



#5 farid.k

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Posted 22 May 2020 - 01:50 AM

As you reasoned, less potential for chattering.

Thanks for the feedback

#6 fallah

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Posted 25 May 2020 - 11:03 PM

 

A bellows can be used to keep debris/solids in the discharge away from the spring and moving parts.


Thanks for the feedback. Any issue i.e. potential of chattering? I don't think so since it can tolerate more back pressure.

 

 

Hi Farid,

 

There is the potential for bellows failure due to fatigue...hence when the back pressure is equal to or less than 10% there would be no reason using balanced bellows type of PSV...



#7 farid.k

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Posted 26 May 2020 - 10:59 AM


A bellows can be used to keep debris/solids in the discharge away from the spring and moving parts.

Thanks for the feedback. Any issue i.e. potential of chattering? I don't think so since it can tolerate more back pressure.
Hi Farid,

There is the potential for bellows failure due to fatigue...hence when the back pressure is equal to or less than 10% there would be no reason using balanced bellows type of PSV...
Dear Sir Fallah,

Thanks so much for the feedback. Actually consultant calculate the built up back pressure considering all main header pipe length until flare unit and utilize the total relieving rate (relieving from system A + relieving from system B ) for the worst case resulting the value for built up back pressure is high, and balance bellow rv type was selected. In actual condition system A would not pop up togather with system B. That's why i am asking what if i do re-visit the calculation and the total back pressure is less then 10%. Do i need to change the RV type to conventional if the result really <10%

Edited by farid.k, 26 May 2020 - 10:59 AM.


#8 fallah

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Posted 26 May 2020 - 10:26 PM   Best Answer


Thanks so much for the feedback. Actually consultant calculate the built up back pressure considering all main header pipe length until flare unit and utilize the total relieving rate (relieving from system A + relieving from system B ) for the worst case resulting the value for built up back pressure is high, and balance bellow rv type was selected. In actual condition system A would not pop up togather with system B. That's why i am asking what if i do re-visit the calculation and the total back pressure is less then 10%. Do i need to change the RV type to conventional if the result really <10%

 

 

Hi Farid,

 

If actually there is no simultaneous relieving from systems A and B resulting back pressure less than 10% in all cases, you can change the RV type to conventional one...but if bellows one is already installed no need to change...






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