How to convert one pipe sie to another in terms of equivelent length?
How to convert one pipe sie to another in terms of equivelent length?
(OP)
Years ago I used a simple furmula to convert one pipe size to another in terms of equivelent length. I.E. 20ft of 2" SCED40 Steel is equivelent to 7.2 Ft of 3" Sched 40. I realize the I can do this with the K values if f is known. I think the equation came from the "Pipeline rules of thumb". I do not have this book in hand. Any help would be appreciated.
Thanks....
Thanks....





RE: How to convert one pipe sie to another in terms of equivelent length?
The equivalent length of a 2" line, if calculated as a 1" line, would therefore be 1/32x its actual length.
In your example, 20 ft of 2" line would be equivalent to about 150 ft of 3" line.
Hope this helps.
Katmar
RE: How to convert one pipe sie to another in terms of equivelent length?
RE: How to convert one pipe sie to another in terms of equivelent length?
The ratio of the two ID's raised to the fifth power times the 20 ft gives you 144 ft. That's a 9% difference which is probably not within the accuracy of the calculation. Katmar's way is a lot easier.
David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: How to convert one pipe sie to another in terms of equivelent length?
Thanks again!
RE: How to convert one pipe sie to another in terms of equivelent length?
As an example, the friction drops in ft/100 ft tabulated in the manual are:
2 in. sch 40 3 in. sch 40 4 in. sch 40
GPM e/D=0.00087 e/D=0.000587 e/D=0.00047
100 17.4 2.39 (7.3) 0.624 (27.9)
200 66.3 8.90 (7.4) 2.27 (29.2)
300 146 19.2 (7.6) 4.89 (29.9)
The conversion factors are parenthesized. So, 20 ft of a 2" pipe would be roughly equivalent to 20*7.5=150 ft of 3" pipe, and to 20*29=580 ft of 4" pipe.
RE: How to convert one pipe sie to another in terms of equivelent length?
rmw