On Jul 19, 8:10*am, Wayne Whitney wrote:
On 2010-07-19, DD_BobK wrote:

Got a cite specifically for low pressure gas flow equivalent
lengths?

From my first post, just google "natural gas 90 equivalent length".
The first hit should do it.

And most people can follow the PDF method way easier than the calc's
method.

My original post was very long because as a mathematician I want to
explain why we are doing the calculations. *Certainly it can be
reduced to using a chart like the PDF method. *All you would need to
do is this:

Change the chart in the PDF to be pipe size versus flow rate, giving
the maximum allowed length. *That's just presenting the same
information in a different way, you can still use the PDF method for
your initial design.

If you want to sharpen it, label each segment with the ratio of
"segment length/chart maximum allowed length". *A solution is OK if
for each appliance, the sum of the ratios from the meter to the outlet
is less than 1. *So if you see that somewhere the sum ends up quite a
bit less than 1, you can try downsizing an appropriate pipe segment,
update the segment ratios, and see if the sum is still less than 1.

Cheers, Wayne


Wayne-

Yes, your modification would allow very rapid & simple itteration
(which the current PDF does but not nearly as easily)

But Wayne, you'd be asking people to create ratios and add a few
numbers! j/k


Did you ever here the one about how an engineer, a physicist
and a mathematician each respond to a small house fire in the middle
of the night?

cheers
Bob