Pipe Flow calculations.
Pipe Flow calculations.
(OP)
In my company we use a 4" mild steel main pipe for delivering fluids to and from tanks.
We are thinking of changing a certain section of it to 6".
will that allow for increased volume flow through the pipe with teh same pump?
Or will the sections that are 4" restrict and give the same flow as if there was all 4" piping?
What calculations would i use to calculate teh volume flow through a certain size of mild steel pipe?
We are thinking of changing a certain section of it to 6".
will that allow for increased volume flow through the pipe with teh same pump?
Or will the sections that are 4" restrict and give the same flow as if there was all 4" piping?
What calculations would i use to calculate teh volume flow through a certain size of mild steel pipe?





RE: Pipe Flow calculations.
I'd suggest you get a copy of Crane's technical paper, it will give you a good background in quantifying this.
RE: Pipe Flow calculations.
If the pump is a fixed speed, positive displacement pump the flow will remain the same.
If the pump is a fixed speed, centrifugal pump the flow will depend where on the pump curve you are. If you are already near the end of the curve, you may not see a measurable increase in flow.
Get Crane's TP 410 like TD2K said.
Good luck,
Latexman
RE: Pipe Flow calculations.
RE: Pipe Flow calculations.
With a larger diameter pipe, can we say that the friction drop is less and hence, with the same pump and motor combination, we can get a higher flow ?
HVAC68
RE: Pipe Flow calculations.
Rotary pumps, belonging to the displacement pump category, may increase flow as a result of less friction) back pressure, due to reduced internal slip effects, especially on low viscosity fluids.
RE: Pipe Flow calculations.
RE: Pipe Flow calculations.
If you have a centrifugal pump, and by using a 6" , your line curve will become a "bit" flat.
Pressure drop = function of (1/D^5 ) .. check in text books.
The drawback is you will probably hit the pump curve on the right side..means your pump will work also under another efficiency.
My suggestion is to draw the two line curves (the one with4 and the other with 6"), draw them on the pump curve (of course use same units)..
Then you will see the pump consumption, efficiency ,...
RE: Pipe Flow calculations.
Replacing some of the pipe with larger diameter should push the System Resistance Curve to the right, as head loss should be reduced for any given flow. How much depends on how much pipe is replaced, as TD2K pointed out.
RE: Pipe Flow calculations.