2 replies to this topic

[Harshp1710]

Hello all,
Suppose i need control valve of flow rate 10m3/hr. Now during designing we are considering Normal, Maximum and Minimum flow rate. So how to calculate this flowrate??

[Chemitofreak]

Hi,

 

Control valve is sized for the following case

 

1) Max Flowrate and Min Press Drop

 

2) MIn Flowrate and Max Pressue Drop

 

Generally we know the Normal Flowrate, this is the Process requirement.

 

We add a design margin (lets say 10%) on top of normal flowrate to get the max flowrate i.e. Max Flow = 1.1 Normal Flowrate

 

Minimum flowrate is based on the turndown requirement i.e. minumum flow for which the plant needs to be operated (This generally is around 30%) i.e. Min Flow = 0.3 x Normal Flowrate. There are situations where this value can be zero as well.

[breizh]

Hi ,

Attached links to support your work 

https://www.control-...com/worksheets/

 

http://www.cheresour...g-and-selection

 

Good luck

Breizh

Edited by breizh, 06 April 2020 - 03:18 AM.