Gas Pipe Rupture Release Rate

[slynk]

Hey all,

Any idea how I can calculate the 3.5 barg nitrogen gas flow rate from a pipe when there's a pipe rupture? Pipe size is 1 in.

I've tried using the choke equation, but the value gotten was quite small.

We did a rough trial (by just fully opening the valve) on site using a 1" compressed air pipe of 2 barg and it already gave 24m3/h, way above that calculated from choke equation.

Are there any other equations available?

Thanks in advance!

 

[TD2K]

Are you talking a clean rupture across the end of the pipe or a hole?

If we are talking about a clean break and if you have a supply system that at 'some' point maintains the 3.5 barg pressure then you just have a straight forward hydraulic calculation to do. Crane technical paper 410 would be a good 'how to' guide.

The flow rate is going to depend how much 1" piping you have. If the pipe ruptures right at a large storage tank for example maintained at 3.5 barg then you'll have a much higher flow rate than if the break occurs 200' down the length of 1" piping.

If the supply system isn't going to be able to keep up and the pressure in the system falls then you have a transient analysis and that's going to take a while.