## system curve

## system curve

(OP)

i want to get the system curve of a pipeline , i ask about the method,i calculate th loss for fixed flow rated and i use the formula : PDC = a * (Qv^2)to get the curve.

with

PDC is the losshead in the system

Qv is the volume flow rate

when can i use yhis formula ?

is there any other method ?

with

PDC is the losshead in the system

Qv is the volume flow rate

when can i use yhis formula ?

is there any other method ?

## RE: system curve

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

## RE: system curve

## RE: system curve

Did you actually look at any of the links to see how its done - guess not?

There are even online calculators to make your life easy.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

## RE: system curve

## RE: system curve

Send me 10.

## RE: system curve

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

## RE: system curve

## RE: system curve

Technology is stealing American jobs. Stop visas for robots.

## RE: system curve

TTFN (ta ta for now)

I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg

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## RE: system curve

## RE: system curve

Technology is stealing American jobs. Stop visas for robots.

## RE: system curve

PDC = Hl + ( a * Qv^2)

Where Hl is the static head loss at zero flow or any sort of static pressure at your end point converted to head.

Also whilst pressure drop is proportional to flowrate ^2, it is not a precise curve as Re no changes.

In the example given above , Hl is about 34ft.

In low head systems something like the difference in liquid level in a tank at the end point can change your system curve enough to make a difference.

Remember - More details = better answers

Also: If you get a response it's polite to respond to it.

## RE: system curve

Technology is stealing American jobs. Stop visas for robots.

## RE: system curve

when can i use this formula ?This formula is used with full pipe flow. Plot the system curve on a graph with the pump performance curve. See the example to balance the pump curve and system curve:

www.ce.utexas.edu/prof/maidment/ce356Fall04/docs/P...

is there any other method?

Yes, but this is the easiest method for day to day tasks.

## RE: system curve

You can convert your single calculated point to a curve using the following formula:

H= [(PCD-StaticHead)/(Qv^2)] xF^2 +StaticHead

Where

His head of fluid as a function of FFis flowStaticHeadis your lift and/or tank pressurePCDis head at your single calculated pointQvis flow at your single calculated pointYou can find your operating head (

H) for any value ofFby curve-fitting the pump curve to a 2nd order polynomial and setting the two formulas equal to each other then finding zero. Then use the quadratic equation to solve forF. PlugFback into the equation above to find the correspondingH.I used to count sand. Now I don't count at all.

## RE: system curve

Mike Halloran

Pembroke Pines, FL, USA

## RE: system curve

I used to count sand. Now I don't count at all.

## RE: system curve

Is there a discount for multiple copies? I presume the software comes with full QA and Certificate of conformity? Do you need excel or is it a self-contained software package?

## RE: system curve

Richard Feynman's Problem Solving Algorithm

1. Write down the problem.

2. Think very hard.

3. Write down the answer.