Page 159 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

'Fable 2-22

Friction losses in pipes carrying water
Among the many empirical formulae for friction losses that have
been proposed that of Williams and IIaaen has been most widely
used. In a convenient form it reads:
in which
f = friction head tn ft of liquid per
d4~5'365 100 ft of pipe (if desired in lb per
sq in. multiply f X .433 X sp gr)
d- inside dia of pipe in inches Head loss 1 Velocity 1 Velocity 1 Headloas
q= flow in gal per min ft per 100 ft ft per sec head ft ft per 100 ft
C = constant accounting for surface I-
roughness
This formula gives accurate values only when the kinematic
viscosity of the liquid is about 1.1 centistokes or 31.6 SSU, which
is the case with water at about GOF. But the viscosity of water varies
with the temperature from 1.8 at 32F to 29 centistokes at 212F.
The tables are therefore subject to this error which may increase
the friction loss as much as 20% at 32F and decrease it as much as
20% at 212F. Note that the tables may be used for any liquid
having a viscosity of the same order as indicated above. % Inch
Values of C for various types of pipe are given below together
with the corresponding multiplier which should apply to the tabu. FLOW I STANDARD WT STEEL EXTRA STRONG STEEL
lated values of the head loss, f. as given on pages 29 to 48.
us .302" inside dia L!
gal _______-__ -
per
I VALUESOFC mm ft per scc Velocity ft per 100 ft ft per scc. Velocity ft per 100 ft
Velocity
Head loss
Velocity
Head loss
head ft
head ft
Range Averag 3ommonly 0.4 1.23 .02 5.22 1.79 .05 13.0
-
used
.05
High= value value for 0-6 1.85 .09 11.1 2.69 . 11 27-4
for
.20
46.1
0-8
2.47
18.8
3.59
TYPE OF PIPE best, good, design 1.0 3.08 .15 28.5 4.48 .31 70.6
smooth, clean, purposes 1.2 3.71 .21 39.9 5.38 .45 98.9
well laid new
-
LOW= pipe 4.33 .29 53.0 6.27
7.17
67.9
.38
4.94
poor or 5.55 8.07
8.96
Cement-Asbestos. ........................................ 160-140 - 140 6.17 11.2
7.71
150
150 140
148 140 3A Inch
150
__ 140
-
140
Iooa-stave ................................................. - 130 STANDARD WT STEEL GXTRA STRONG STEE4
110
120
-.
Welded and seamless steel.. ................................ 150-80- 140 100
Continuous-interior riveted steel (no projecting rivets or) .493" inside dia .423" inside dia
joints .................................................. __ 100
bl lrought-iron.. ............................................. I 150-80 100
cast-iron.. ................................................. !P!--sO 100 ft per sec head ft It Per 100 ft ft per sec head ft ft per 100 ft
Velocity I Velocity I Head loss
Velocity I Velocity 1 Head loss
Rdi-riveted steel (Droiectina rivets in girth and horizontal I=- 145-XU - 100 0.8 1.31 .03 4.30 i.83 .05 13-7
Tar-coated cast-iron. .......................................
100
Girth-riveted steel (projecting rivets in girth seams only).. .
130
9.107
Concrete ...................................................
100
120
152-85
.os
6.50
t -0
2.28
1.68
.04
..
.................................................
I
seams)
4.67
Vitrified.. .................................................. 115 100 1.6 3.43
110
100
Spirakiveted steel (flow with lap).. ........................ 110 100 2.6 36.4 5.71
Spiral-riveted steel (flow against lap). ...................... 90 1.0 5.05 ~ 40 49.6 6.85 .73 106
Corrugated steel.. .......................................... 60 11.4 9.14 1 sif I @
8.00
Valueof C.. .................... ..I 150 I 140 I la0 I 120 I 110 I 100 I 90 I 8 70 60 6.0 8.41 1.10 134
___-___-____---
Multiplier to correct tables. %. , . . , . lkd .54 1 .62 I .?1 I .84 I 1.0 I 1.22 1 1.58 I 1.93 I 2.57 1.58 179 13.7 377
d
*By perniission 6. V. Shaw and A. W. Loomis Cameron HydraulicData, 11th Edition, Ingersoll-Rand Go., 1942 [531. G