How do I calculate equivalent length of water pipe for vertical pipe runs?

[MechEng92]

I have a target of X meters for water pipe, I'd like to calculate how much vertical pipework I can have that would equate to X meters for different pipe diameters.

 

[PEDARRIN2]

Equivalent length is used in pressure drop calculations to equate pipe fittings to a "pipe length" to insert into the calcs. The equivalent length of a pipe is equal to its actual length.

 

[LittleInch]

I don't really understand your question.

If what you're looking for is the equivalent length of pipe which equates to the additional head from a vertical pipe then this will vary by flow rate.

Can you be a bit clearer what your question is.


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[MechEng92]

Hi Matthew,

We have a given flow rate for the system and a pressure drop of the indoor unit and outdoor unit. We have a spec to design for a certain length of pipework, but I would assume if the majority (or all) of the pipework was vertical instead of horizontal then it would equate to less than the design length of pipework due to gravity?

Just like accounting for fittings and bends where there is an equivalent length, I just assumed there would be something similar for vertical pipework.

 

[LittleInch]

I would need to see a sketch of the system, but I think you're confusing two elements of the system, but I might be mistaken.

Pressure drop or head required for your pipework is dependent on friction losses and head losses or gains from start to finish with allowance for high points also.

Friction losses is straight pipe length plus added length for bends, fitting etc in the equivalent length method.

Head difference is vertical difference from inlet to outlet ( positive or negative). so not really the same thing as equivalent length?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.