Jump to content



Featured Articles

Check out the latest featured articles.

File Library

Check out the latest downloads available in the File Library.

New Article

Product Viscosity vs. Shear

Featured File

Vertical Tank Selection

New Blog Entry

Low Flow in Pipes- posted in Ankur's blog

Restriction Orifice Sizing


This topic has been archived. This means that you cannot reply to this topic.
2 replies to this topic
Share this topic:
| More

#1 earnest

earnest

    Brand New Member

  • Members
  • 1 posts

Posted 23 August 2014 - 02:33 PM

Dear Engineers:

 

I have a control valve that reduce discharge pressure of a multistage pump from 55.9 bara to 0.25 bara.

 

The valve acting as minimum flow for pump.  But sometimes this valve needs to be dismantled and the minimum flow to be controlled with a by pass which is a simple globe valve.  Because of this high delta P, adjustment of flow by globe valve is not possible.

 

I decided to use a restriction orifice after the globe valve on bypass line, but after calculation by spnkflo program, it says the velocity is very high and I should use a multihole orifice.  I didn't bring the delta P over the globe in the calculation.  My beta ratio is too low too.  So what can I do instead of this orifice?  Or how I can decrease the pressure?

Here is the data of my calculation:

 

Fluid: liquid

T = 56 C                   ID = 76.2 mm        Density = 851 kg/m3         viscosity = 0.668 cp           

dp over orifice = 55.65 bar            normal flow = 1.044 kg/s

result: d = 4.7435 mm,v = 68.48m/s 

           

I hope someone could help.              



#2 fallah

fallah

    Gold Member

  • ChE Plus Subscriber
  • 4,930 posts

Posted 24 August 2014 - 01:17 AM

earnest,

 

Did you test using series (two or three or...) of restriction orifices?



#3 breizh

breizh

    Gold Member

  • Admin
  • 6,292 posts

Posted 24 August 2014 - 03:11 AM

Earnest,

Consider this resource for RO in serie, as per Fallah's suggestion . At the end of the document , you have useful references .

 

http://wenku.baidu.c...dccda38376baf4e

 

Hope this helps.

 

Breizh






Similar Topics