Punctured Pipeline: Estimate Oil Release Rate

[kolis]

Hi,
I've got punctured pressurized pipeline transporting an oil. Diameter of pipeline is 50 mm and diameter of the hole is only 2 mm. Pressure in the pipeline is 20 bar and pressure outside is atmospherical. The rate of transported oil is 2m3 per hour and I need to estimate released volume of oil, while pump is still working so I have two flows: one through the hole and another one continuous in pipeline after the hole.
Any help will be appreciated. Thanks

 

[berkeman]

Hi,
I've got punctured pressurized pipeline transporting an oil. Diameter of pipeline is 50 mm and diameter of the hole is only 2 mm. Pressure in the pipeline is 20 bar and pressure outside is atmospherical. The rate of transported oil is 2m3 per hour and I need to estimate released volume of oil, while pump is still working so I have two flows: one through the hole and another one continuous in pipeline after the hole.
Any help will be appreciated. Thanks

Welcome to the PF.

Is this question for schoolwork?

 

[kolis]

No it's not schoolwork.it has happened and I would like to know how much oil has leaked out.

 

[Q_Goest]

Try an online orifice flow calculator. For "orifice constant" (discharge coefficient) use 0.62 or 0.82. The value should be between these two.

http://www.pumpcalcs.com/calculators/view/103/

 

[kolis]

Ok. But I've still got a problem with understanding this: When I've got a hole in a pipe there are two flows (one trough a hole and 2nd in pipe), so the flow through the hole is just a fraction of incoming flow. In equation it should be Qin=Qhole + Qpipe after hole and when I calculate flow through an orifice its just one flow so Qin=Qorifice
Or am I wrong?

 

[Q_Goest]

Yes, flow through orifice is a fraction of total flow in. Let's say the flow out the orifice is 2 GPM which equates to 0.45 cubic meters per hour. If you have a flow of only 2.00 cubic meters per hour before the orifice, you only have a flow of 1.55 cubic meters after the orifice.

 

[kolis]

Ok.
I've found another equation to estimate leakage amount through small holes in a pipeline. It says:
Q=0.61A(2gh)^0.5

where
Q is flow in cu. ft./second
A is cross sectional area, sq. ft.
g is gravitational constant, ft/sec^2
h is head, feet
It looks like this is the right equation for me. Problem is, I don't know what is head or how can I calculate. Any help?

 

[Q_Goest]

Head is simply how much pressure a column of liquid of a given height creates on the Earth. It can be calculated as shown here: http://en.wikipedia.org/wiki/Pressure_head