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# How To Find The Relief Load For The Fire Case

relief

9 replies to this topic
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### #1 Sami222

Sami222

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Posted 18 January 2022 - 02:01 PM

Greetings,

Is there any specific equation to calculate the relief load (Vertical Mixing Vessel) for the fire case? Approximate the vessel wetted surface area by using a cylinder around the dished ends.

Also, how we can calculate the relief valve area for the fire case?

Thanks!

### #2 Bobby Strain

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Posted 18 January 2022 - 04:32 PM

Why, as a student, are you interested in such? And you have obviously done no research. The best lesson you can learn is to first, do some work. Then ask questions about what you don't understand.

Bobby

### #3 latexman

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Posted 18 January 2022 - 06:45 PM

How To Find The Relief Load For The Fire Case

### #4 breizh

breizh

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Posted 18 January 2022 - 07:01 PM   Best Answer

Hi,

Let you study these materials .

Many more using your favorite search engine or the search button in this forum .

Engineering is about hard work .

Breizh

### #5 Sami222

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Posted 20 January 2022 - 06:35 AM

Breizh:

Many thanks for reply. I really find the material you provided is very helpful!

I almost find what I need, but I have question to confirm my understanding;

I used to find the wetted area this equation since the question mentioned (Approximate the vessel wetted surface area by using a cylinder around the dished ends)

Awett=PI*D*Feff

then to find Feff I used this equation:

Feff= min(25 ft;F) - H

Regarding (F) is it the maximum liq level(trip) or the vessel length ?

Thanks!

### #6 Sami222

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Posted 20 January 2022 - 06:41 AM

Why, as a student, are you interested in such? And you have obviously done no research. The best lesson you can learn is to first, do some work. Then ask questions about what you don't understand.

Bobby

Many thanks for your reply. It's not part of our course, but the instructor gives us a challenging question with limited time to answer. Yes, it supposes to do some research first. Sorry for that!

### #7 breizh

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Posted 20 January 2022 - 07:42 AM

Hi,

F is the liquid level .

Take a look at the 2 nd document , you will find an example .

Good luck

Breizh

### #8 latexman

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Posted 20 January 2022 - 07:45 AM

For vertical tank/vessel we use 85% LL unless there’s a good reason not to.

### #9 Sami222

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Posted 20 January 2022 - 10:58 AM

Hi,

F is the liquid level .

Take a look at the 2 nd document , you will find an example .

Good luck

Breizh

Many thanks I see the example 7.4.10.11. but I have question how calculated the free surface of Benzene 32 ft over the ground.

### #10 breizh

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Posted 20 January 2022 - 07:02 PM

Hi,

It should be 27=( 15+12)

Breizh