3 replies to this topic

[BOUKHLAZ]

Dear All,
 
I would like to ask you some question concerning vent sizing (my first calculation). After calculating the venting requirements according the API 2000, I want now to size the vent (diameter) and I need some information: 
 
-          What are the criteria in term of velocity and pressure drop we have to follow when doing the line sizing of the vent?
-          What will be the pressure drop ? do we consider only 2 elbows, pipe entrance and exit ? is there any assumption for the straight pipe length and for the insect/dust screen pressure drop?
-          The total pressure drop is the design pressure of the tank (overpressure) is it correct ? how do we calculate the negative design pressure (vacuum)?
-          In case of outbreathing of water storage tank, do we use the air properties to do the calculation? (there are no properties of water vapor at standard conditions)
 
Your help would be greatly appreciated.
 
Thanks in advance.
 
Best regards.

 

Zakaria

[fallah]

 
-          What are the criteria in term of velocity and pressure drop we have to follow when doing the line sizing of the vent?

Velocity: Below sound velocity in the same conditions Pressure drop: Below tank design pressure 
-          What will be the pressure drop ? do we consider only 2 elbows, pipe entrance and exit ? is there any assumption for the straight pipe length and for the insect/dust screen pressure drop?

Lower than tank design pressure. Entrance loss should also be considered 
-          The total pressure drop is the design pressure of the tank (overpressure) is it correct ? how do we calculate the negative design pressure (vacuum)?

Maximum total pressure drop can be equal to tank design pressure. Design vacuum around one inch of water column
-          In case of outbreathing of water storage tank, do we use the air properties to do the calculation? (there are no properties of water vapor at standard conditions) 

If the temperature isn't so high, you can use...
 

 

Edited by fallah, 14 April 2015 - 01:53 AM.

[breizh]

http://www.enardo.co..._model_4100.htm

 

You may consult this vendor .

 

hope this helps

 

Breizh

[BOUKHLAZ]

Thanks a lot Fallah & Breizh.

 

Certainly I will ask you some questions, I have some comments.

 

Zakaria