# Calculating Pipe Leak Flow Rate

Just curious and working on some hypothetical problems on my own...I'm currently studying for my PE license. Also, trying my best here with the Latex stuff.

Let's say there's a crude oil pipeline and it somehow gets a hole in it and begins to leak. If you wanted to calculate the flow rate through the hole, my understanding is that you would approach the problem in the following manner:

$$Q = CA_0\sqrt{2g_c\frac{P_1-P_2}{\rho}}$$

Where:

$$A_0$$ = cross-sectional area of orifice (leak hole) = $$\frac{\pi*d^2}{4}$$ = $$\frac{\pi(2)^2}{4}$$ = $$3.14 in^2$$

$$P_1$$ = 1,000 psi (pressure in pipeline)

$$P_2$$ = 14.7 psi (atmospheric pressure on outside of pipe)

$$\rho$$ = density of crude oil = 870$$\left(\frac{kg}{m^3}\right)$$ $$\left(\frac{2.2 lb}{kg}\right)$$ $$\left(\frac{1m}{3.28ft^3}\right)^3$$ $$\left(\frac{1ft}{12in}\right)^3$$ = $$\frac{0.031lb_m}{in^3}$$

$$g_c$$ = 32.2$$\frac{lb_m*ft}{lb_f*s^2}$$ = 386.4$$\frac{lb_m*in}{lb_f*s^2}$$

So I get the following:

$$Q = C3.14in^2\sqrt{\left(772.8\frac{lb_m*in}{lb_f*s^2}\right)\left(\frac{\frac{985.3lb_f}{in^2}}{\frac{0.031lb_m}{in^3}}\right)}$$

Is this the correct approach?

• I would use SI units in your calculation Feb 12, 2021 at 14:28
• Yeah, that certainly seems to make it look cleaner. I'm mainly just going through the unit conversion olympics here to challenge myself. Feb 12, 2021 at 15:47