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thanks

- Thread starter smoque
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- #1

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thanks

- #2

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There are many reasons, and the fact is a lot of it is empirical data.

It has a bit to do with the amount of flow going around the bend that is laminar and the amount that is turbulent.

- #3

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any way to figure out how the statement above is derived?

- #4

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This is generally an empirical study. In carbon steel piping, a normal 90 elbow of 2.5" pipe is equivalent to 9.3 ft of straight pipe.

So if you have 40ft of pipe, then a 90, then 40 ft. You have an "equivalent length" of 40+40+9.3, or 89.3 ft of pipe. You use this along with the friction factor of the pipe material to determine the pressure drop.

Here is a website that shows you some Leq's (equivalent lengths) based on the steel pipe's nominal diameter:

http://www.delftaerospace.org/en/organisation/departments-and-chairs/space-engineering/space-systems-engineering/expertise-areas/space-propulsion/design-of-elements/feed-systems/feed-systems-b/ [Broken] is one that shows you the Leq/D so you can multiply the number by the pipe diameter (in feet) and get the equivalent length

Here Is a site that kind of shows you the math involved

So if you have 40ft of pipe, then a 90, then 40 ft. You have an "equivalent length" of 40+40+9.3, or 89.3 ft of pipe. You use this along with the friction factor of the pipe material to determine the pressure drop.

Here is a website that shows you some Leq's (equivalent lengths) based on the steel pipe's nominal diameter:

http://www.delftaerospace.org/en/organisation/departments-and-chairs/space-engineering/space-systems-engineering/expertise-areas/space-propulsion/design-of-elements/feed-systems/feed-systems-b/ [Broken] is one that shows you the Leq/D so you can multiply the number by the pipe diameter (in feet) and get the equivalent length

Here Is a site that kind of shows you the math involved

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