Pipe Flow Calculations Forum

The calculator for air pressure drop http://www.pipeflowcalculations.com/airflow/index.htm can be used with value of resistance coefficient - K entered. Value for K can be obtained from the valve manufacturer or found in literature. If you can tell me more about the valve - type of valve (globe, gat...

As fluid is considered as incompressible no expansion factor is included in calculator, for this time but will be soon.

For the second point you are right of course and it will be indicated more clearly. Thank you for your analysis.

And just to point out following: I have two questions that I would appreciate if any one help me to find their answers. let's start. The discharge coefficient used for venturi in the calculator is: Cd=a+b.(Ln Re)^2+c.(Ln Re)^3 and apparently the expansion factor used for it, is: Buckingham Eq: Y=1-(...

No, Buckingham's formula is for orifice as you said. Expansion factor formula Y= sqrt((r^2/k).(k/k-1).((1-r^(k-1)/k))/(1-r).(1-beta^4/1-beta^4.r^2/k)) is used for values of D2/D1; D; ReD that are in the range that is stated in ISO 5167-4 for different types of Venturi tubes. Diameters of your Ventur...

Really like your comments, as it will bring better solutions (calculator) at the end... I would like to point out that ISO 5167-4 is covering this "Measurement of fluid flow by means of pressure differential devices ... - Part 4 Venturi tubes" and I think it should be used as reference for...

I have attached full derivation for lake draining problem BUT it has to be checked and some values are needed to be presumed like friction factor is constant which is not because Re number will change from some value to another during drain, but some average value can be used. With last equation: √(...

As the level of lake is going to change that flow is not stationary so the flow rate will drop from some point to zero. Some other calculation methods are required.
What is the difference in height between lake surface and pipe outlet - is it 10 feet as the height of lake?

K factor is resistance coefficient that helps to calculate pressure drop due to minor losses in elbows, reducers, valves etc. On the left side of calculator you can find "K factor" button, when pushed new window with different shapes of pipe fittings can be found. There you can calculate K...

You should tell me the flow rate that you need so the diameter can be calculated. 2 psi is small pressure so you should use pressure drop calculator on: http://www.pipeflowcalculations.com/pressuredrop/index.htm . Or if pressure drop is small and just want to have pipe diameter for given flow rate t...

If you can give me values for pressures and temperature, with calculator on: http://www.pipeflowcalculations.com/orifice/index.htm you can calculate flow through orifice with ease. Also, theory that is used for that calculator you can find at: http://www.pipeflowcalculations.com/pipeflowtheory/flow_...