Brooks 5866, Installation And Operation Manual

Page: 37 / 66

Brooks Instrument Model 5866 Pressure Controller
5-14
Since the C
v
calculated is the same as listed for the .014" orifice the .020"
orifice should be selected. The last step is to check the maximum pressure
drop for the application. The maximum pressure drop for the .020 orifice is
300 psi, this is greater than the 100 psi pressure drop required for the
application so the .020" orifice is correct.
Table 5-4. Model 5866 Orifice Selection.
Orifice Maximum
C
v
Size Pressure Drop (psi)
5.0x10 -6 .001 1500
2.0x10 -5 .002 1500
5.0x10
-5
.003 1500
1.1x10 -4 .004 1500
4.0.x10
-4
.007 1500
9.0x10 -4 .010 750
2.0x10
-3
.014 550
4.7x10 -3 .020 300
1.4x10
-2
.032 175
3.5x10 -2 .048 85
5.5x10
-2
.062 55
8.0x10 -2 .078 50
1.0x10
-1
.093 50
1.4x10 -1 .116 50
1.5x10
-1
.120 50
Figure 5-6. Example Application of Orifice Sizing Procedure.
®
Reactor
N
2
Model 5850E
Mass Flow Controller
500 sccm, Full Scale
®
Model 5866
Vent to
Atmosphere
H
2
Model 5850E
Mass Flow Controller
300 sccm, Full Scale
®
100 psig
Maximum
Desired
Pressure