Leakage rate through an orifice

[ukd]

Hello,

I have a production flow line (8") flowing with a pressure of 8 barg,65 deg C,density of 100 kg/m3,velocity of 20 m/s and i would like to calculate the leakage rate through a 2" orifice.If there is a leakage,the segment that I will have by closing the sectionalisation valve will be 2m3.

I am wondering which formula to find the leakage rate.Can anybody help me out.

Regards,
UKD

 

[165189]

apply Bernoullis principle, P1/roe+1/2*roe*v1^2 =P2/roe+1/2*roe*v2^2

P1-P2=line pressure-atmospheric pressure,

v1=line velocity

then find velocity through orifie,v2.

calculate the flow rate=pi/4*di^2*v2

 

[casflo]

UKD, you can use 2 approachs, one could be to assume the 2" orifice in the pipe wall as a pipe exit, K = fL/D = 1 and use this term as the pipe friction to apply in Bernouilli equation and the other approach could be to calculate the pressure drop through the 2" orifice in the same manner as a sharp edge restriction orifice with d/D = 2/8 = 0.25.
See for example the Crane Technical Paper No 410

 

[sprintcar]

Everybody refers to the Crane 410 but only the lucky ones seem to have a copy! Is there an online version?
Thanks!

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[ukd]

Hello,

Thanks for you answer.I am wondering by using bernoulli's equation, I will get steady mass flowrate which is the intial mass flow (peak rate).I would like to account the change in mass flow rate and upstream pressure with respect to time.

Could anyone suggest me how to do that?

 

[dogtop]

FYI:

http://www.tp410.com/

HTH