Orifice sizing

[sandipr]

I want to find out orifice dia, upstream side pr. 3.5 kg/cm2, line size 3 inch and i want 1 kg/cm2 pr. On downstream i dont know how much steam flow is there.

 

[JLSeagull]

If you want a restriction orifice to drop the pressure it is dependent upon flow rate. Perhaps a control valve would be a better solution.

 

[Latexman]

Sounds like it may be an application for a pressure regulator too.

Good luck,
Latexman

 

[MortenA]

check out this FAQ:

http://www.eng-tips.com/faqs.cfm?fid=1196

Best regards

Morten

 

[djack77494]

The system you describe has a dP above critical. It will serve to limit the steam flowrate, but "won't care" what the downstream pressure is.

 

[sailoday28]

Morton
The pressure, density and/or temp in the first of the equations at the referenced site are misleading. Pressure and temp and /or density should be in terms of stagnation conditions. Use of static p, T or density will lead to some error depending upon the upstream Mach number.

I believe the original derivation of the equation was based on quasi steady flow from a large area reservoir thru a "much smaller area" orifice (negligible upstream velocity) such that upstream static and stagnation conditions are equivalent.


Regards

 

[MortenA]

sailor - the way you spelled my name is misleading ;-)

Anyway - i dont make the FAQ - but hopfully Milton will see this and corret if nescesarry.

Best regards

Morten