|
Kd Values For Psv Sizing
#1
Posted 21 April 2017 - 10:04 PM
I am currently working in FEED project for Hydrocarbon Gas processing Plant and doing PSV sizing calc.
In Sizing calculations, we are using Kd values with 90% derating factor as prescribed in ASME (Certified Kd is 90% of avg from tests done)for required area estimation and the rated capacity is based on API effective orifice areas as in API-526 in the absence of Manufacturer valve selection.
As an example,in one case, we got required relief area as 6.48 inch2 with Kd value 0.88 and we selected API Q orifice. Had we used Kd = 0.975, P orifice size would have been sufficient, and in some other cases, no. of PSV required are varying for required relief.
Can we follow this practice for FEED level project...Please clarify...
#2
Posted 22 April 2017 - 06:35 AM
hi ,
Take a look at the document attached , you should find your answer .
Hope this is helping you.
Breizh
Edited by breizh, 22 April 2017 - 07:10 AM.
#3
Posted 22 April 2017 - 07:13 AM
hi ,
Take a look at the document attached , you should find your answer .
Hope this is helping you.
Breizh
#4
Posted 22 April 2017 - 07:54 PM
You should size based on ASME basis if this is required. If this is the case,use the "Red Book" to get manufacturers area values.
Bobby
#5
Posted 22 April 2017 - 08:25 PM
#6
Posted 23 April 2017 - 01:25 AM
aniljani,
if you are a process engineer your method, enriched by Breizh and Bobby Strain comments, is enough.
But, obviously, the final choices are in the hands of the manufacturer of each PSV.
Good luck!
#7
Posted 30 April 2017 - 01:37 AM
If you are doing FEED, it is preliminary sizing, you are using API effective areas use kd = 0.975 for vapour.
If you are are using actual area of a selected valve then use K factor supplied in red book for vapour.
Either use API effective area & API Kd for sizing OR;
use ASME area & ASME K for sizing
Your result for selected valve size should be similar. Just don't mix the API / ASME.
Edited by ChemEng01, 30 April 2017 - 01:47 AM.
Similar Topics
Sizing Of Vertical/horizontal Flash DrumStarted by Guest_Mohammad3799_* , 10 Mar 2024 |
|
|
||
Design Criteria For Sizing Sump Drum Of Close Drain System In Tank FarStarted by Guest_AnbIran_* , 28 Feb 2024 |
|
|
||
Ro SizingStarted by Guest_T_bag_* , 27 Feb 2024 |
|
|
||
Vent Sizing Using GooseneckStarted by Guest_mychemicalromance0425_* , 23 Feb 2024 |
|
|
||
Answered
Nozzle Sizing CalculationStarted by Guest_BabRafiq1_* , 26 Aug 2022 |
|
|