hydraulic pipe calculations in conceptual or basic design phase

[Yobbo]

L.S.,

Somewhere I read an article about how to make hydraulic pipe calculations with limited information during the basic design. It gave some guidelines about how to estimate the amount of bends and other things causing pressure loss based on the pipe length.
I don't seem to able to find it. Is there someone out there, with whom a bell starts ringing, while reading this? If so, I really would like to get a copy of the said article. If there are any literature sources on this subject that might be interesting I am all open for it.

With best regards,

Karel Postulart, The Netherlands
Nuon Power Generation

 

[BigInch]

It's best you don't look for it. This is highly dependent on what type of facility you're building.

If you're talking for a typical pipeline, I might reserve 2.5 to 5% for losses at a station.

What would you be doing, if you knew that you could not fail?

 

[vpl]

Yobbo

Might you be thinking of the Crane Technical Paper 410 "Flow of Fluids?" Not much good for the oil pipelines that BigInch works with, but pretty decent place to start for something smaller.



Patricia Lougheed

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[TD2K]

I've done it a couple of ways.

If it's within a unit, I've allowed 10 psi for piping line losses. For supply/rundown lines to tankage, 20 to 30 psi. You then add elevation, instrumentation and equipment pressure drops as necessary.

Piping within a unit is usually designed for a few psi/100' so 10 psi gives you a reasonable allowance for straight line losses.

If you have a plot plan, then I've scaled off where I think it's likely how piping will run the pipe to get the straight run piping, add elevations) and then add 20% to 50% for fittings to estimate the line losses. If you have a convulated piping configuration you can increase the fitting allowance but I think 100% is about as high as I would go for fittings. Piping to/from a tank farm would be at the lower end for fitting allowances and for a pipeline as BigInch says, it's minor.

 

[BigInch]

OK, a little more specific. Into a station, or tank farm, with metering, flat ground, I generally try to get there with 50 psi. 20 psi for the meters & prover, 10 psi to run from meters to tank and 20 psi to fill to the top of the tank. Starting out with 1000 psi plus for minimal elevation changes, that's roughly 5%. But as I say, highly dependent on what you're doing at the moment and how much pressure you have to begin with.

What would you be doing, if you knew that you could not fail?

 

[SeanB]

You might be thinking of "How to Predict Pressure Drop Before Designing the Piping" by Grant S Brown. I have used his correlation and set up an excel spreadsheet whereby I input the pipe diameter, the plot plan straight line distance and the piping complexity factor. This then calculates the total equivalent length. You still have to throw that into a hydraulic program to calculate pressure drop though.