K-Factor of Venturimeter

[Suhshi]

Hi,
Can anyone guide, what is the 'K-factor' of Venturimeter and is there any limit (min/max), say for a application of gas flow rate (1-15 MMSCFD) measurement,4" pipe, 2600 psig pressure. Any guidelines to go for consistency if it is not within acceptable limits?
Thx

 

[EmmanuelTop]

Differential pressure devices usually have turndown ratio between 3:1 and 4:1, hence Venturi is far away from the best choice for this application.

If you are looking for 15:1 turndown and the service is clean, Ultrasonic or Vortex could be the right choice.

Dejan IVANOVIC
Process Engineer, MSChE

 

[Suhshi]

Thanks Emmanuel.
This is for gas well flow line application, service is not clean...but i am perticularly looking for the information about the 'K-Factor' of the Venturimeter if the 4:1 is accepted for this application...

 

[georgeverghese]

Think Suhshi is thinking of using a dual range dp cell (lo range / hi range) with this venturi meter, which will make the device good for a turndown of 4 x 4 : 1

These dp cells autoswitch from lo to hi range or the reverse depending on what the flow is.

Well flow is particularly erosive and hence the choice for a venturi meter.

Sorry, I cant help with the K factor either - is this information not in some ISA or AGA standard ? Presume you are looking for K in single phase gas application.

These devices lose accuracy considerably when there is condensate or water together with gas. There are some companies who claim to be able to get good accuracy in 2 phase and even 3 phase operation, but in my experience, all have failed dismally.