How to calculate head

[CordDenton]

Attached below is a basic Paint sketch of the pipeline I am designing here. What I need to know is, how do I calculate the TDH for this? I can't get pumps sized until I know what pressures I'll be working with. Each little black square is a tank battery, which is just storage tanks that will hold saltwater, and a pump to push it into the pipeline. All of these tank batteries feed into one disposal site, the red circle, where the brine will be pumped back into storage tanks. Starting with the upper branch, do I begin to calculate head considering the difference in elevation, friction-loss, etc from point E to the red dot, and then do the same from D to E, and then from C to D, etc. Or do I just use the overall length and endpoint elevations only? This pipeline will be in northwest North Dakota, a fairly hilly area, so the elevation between any two nodes could change by a hundred feet or more.

Crude Sketch.jpg

[PinkertonD]

Hi Cord,

If, I undertand the issue correctly, are the tank storage batteries open to or at atmospheric pressure? Such that the brine is pumped (or flowed) to the first battery then pumped on from there to the next battery? It is then pumped from that battery to the next one.

If so, then the head will be the rise between the start of flow to the first battery. The next head will be from the first battery to the next battery and so on to the red dot.

However, if it is a totally sealed system then the head will be from the supply source to the red dot. Which, by the way, is not a good approach as the pumps will have to handle a lot of pressure = expensive pumps.

[CordDenton]

The tanks will be vented, yes. These are tank batteries in an oil field. The pumps will kick on and off based on tank level gauges. Also, the brine won't flow from tank battery to tank battery, it goes all the way to the disposal site (red dot,) regardless of where it is coming from. So at any given time, the pump at A could be the only one running, and it needs to be strong enough to push the water all the way to the disposal site, but also, at any given time all five pumps on the top branch could be running simultaneously, which like you said, increases pressure. Such pressure fluctuations are not good on centrifugal pumps, so I am looking at progressive cavity pumps. Before anything can be decided though, I need to figure out my TDH.

[PinkertonD]

Cord,

A clear explanation of what you require at the start would save a some of the shuffling back and forth with new information. More precise descriptions will elicit more precise answers.

and it needs to be strong enough to push the water all the way to the disposal site

Ummm, unless you are again leaving something out. I think that answers the question, no?

[Kelly_Bramble]

Attached below is a basic Paint sketch of the pipeline I am designing here. What I need to know is, how do I calculate the TDH for this? I can't get pumps sized until I know what pressures I'll be working with. Each little black square is a tank battery, which is just storage tanks that will hold saltwater, and a pump to push it into the pipeline. All of these tank batteries feed into one disposal site, the red circle, where the brine will be pumped back into storage tanks. Starting with the upper branch, do I begin to calculate head considering the difference in elevation, friction-loss, etc from point E to the red dot, and then do the same from D to E, and then from C to D, etc. Or do I just use the overall length and endpoint elevations only? This pipeline will be in northwest North Dakota, a fairly hilly area, so the elevation between any two nodes could change by a hundred feet or more.

Crude Sketch.jpg

I assume the op has seen this Engineers Edge webpage?

http://www.engineersedge.com/hydraul...sure_10054.htm