Advancedfluidicdesign
forOEMs:
P=
(
9.86 x 10
-8
)
(
F LV
)
d
4
Where:
P=pressuredrop inpsi
V= viscoscity in centipoise (cp)
F= flow rate inmL/min
d= tubing insidediameter in cm
L= tubing length in cm
(See tableabove fordatacalculatedusing this formula.)
TheoreticalPressureDrop
AlongaLengthofTubing
Internal Diameters
Linear Volumes
Inches
WireGauge* Millimeters Microns
µL/in
µL/cm
0.0008 —
0.020
20
0.008
0.003
0.001
—
0.025
25
0.013
0.005
0.002
—
0.051
51
0.051
0.020
0.0025 —
0.064
64
0.081
0.032
0.003
—
0.076
76
0.116
0.046
0.004
36
0.102
102
0.206
0.081
0.005
35
0.127
127
0.322
0.127
0.006
—
0.152
152
0.463
0.182
0.007
34
0.178
178
0.631
0.248
0.008
33
0.203
203
0.824
0.324
0.009
32
0.229
229
1.042
0.410
0.010
31
0.254
254
1.287
0.507
0.012
30
0.305
305
1.853
0.730
0.014
28
0.356
356
2.523
0.993
0.015
—
0.381
381
2.896
1.140
0.018
26
0.457
457
4.170
1.642
0.020
25
0.508
508
5.148
2.027
0.028
22
0.711
711
10.090
3.973
0.030
—
0.762
762
11.583
4.560
0.032
21
0.813
813
13.179
5.189
0.040
—
1.016
1016
20.593
8.107
0.042
19
1.067
1067
22.703
8.938
0.046
—
1.168
1168
27.234
10.722
0.055
—
1.397
1397
38.933
15.328
0.062
—
1.575
1575
49.474
19.478
0.080
14
2.032
2032
82.370
32.429
0.093
—
2.362
2362
111.316 43.825
0.120
9
3.048
3048
185.333 72.966
0.125
—
3.175
3175
201.099 79.173
*WireGaugenumbers are referencingBirminghamor Stub’s IronWireGauge values, which
are commonly usedbymost stainless steel syringemanufacturers.
Tubing InternalDiameters
&Volumes
Tubing Internal Diameter (d) in inches to Linear Volume (µL/inch):
12870.4 (d2)
Tubing Internal Diameter (d) in µm to Linear Volume (µL/cm):
7.85 x 10-6 (d2)
DifferentialPressurePer
5–FootLength
Which ID isbest for your application?Refer toflow rates (usingwater
asthesolvent)andtubing IDsbelowandthecorrespondingdifferential
pressureper 5-foot length.
These theoretical dataarepresented inpsi with thebar equivalent in
parentheses,andwerecalculatedusingtheformulapresentedtotheright.
Tubing ID
FlowRate
0.0025” 0.005” 0.007” 0.010” 0.020” 0.030” 0.062”
0.1mL/min
923
58
15
4
0
0
0
(64)
(4.0)
(1.0)
(0.3)
(0)
(0)
(0)
1.0mL/min
NR*
577
150
36
2
0
0
(40)
(10)
(2.5)
(0.1)
(0)
(0)
2.0mL/min
NR*
1,154 300
72
5
1
0
(80)
(21)
(5.0)
(0.3)
(0.1)
(0)
10.0mL/min
NR*
5,770 1,502 361
23
5
0
(398)
(103)
(25)
(1.6)
(0.3)
(0)
25.0mL/min
NR*
NR*
3,755 902
56
11
0
(259)
(62)
(3.9)
(0.8)
(0)
*Not Recommended—Exceeds thepressure ratingof the tubing.
TECHNICALRESOURCES
187
TubingReferenceData
