Appendix D: MFC Sizing Guidelines
How To Determine the Valve Configuration
71
How To Determine the Valve Configuration
1. Determine the maximum flow coefficient (Cv), for the gas of interest, using the equation:
C
V
(max) = Max. Flow Rate, sccm
C
v
Pressure Factor
1.293
Gas Density
( )
( )
( )
where:
Gas Density is listed in Appendix C: Gas Correction Factors, page 65.
Cv Pressure Factor is listed in Table 12, page 71.
Cv Pressure Factors (multiplied by 100,000)
P1
(psia)
Differential Pressure (psid)
50
40
30
20
15
10
5
2
1
0.5
165
0.042
0.046
0.052
0.063
0.072
0.087
0.122
0.192
0.272
0.384
150
0.044
0.048
0.055
0.066
0.075
0.092
0.128
0.202
0.285
0.403
125
0.049
0.054
0.061
0.073
0.083
0.101
0.141
0.221
0.312
0.441
100
0.058
0.062
0.069
0.082
0.094
0.113
0.158
0.248
0.349
0.493
75
0.077
0.077
0.082
0.097
0.110
0.132
0.183
0.286
0.404
0.570
50
0.116
0.116
0.116
0.123
0.138
0.164
0.226
0.352
0.495
0.699
30
0.194
0.194
0.194
0.220
0.297
0.458
0.642
0.904
25
0.232
0.232
0.246
0.329
0.503
0.704
0.991
20
0.291
0.291
0.291
0.373
0.565
0.789
1.109
15
0.387
0.387
0.441
0.659
0.915
1.283
10
0.578
0.581
0.821
1.131
1.578
5
1.156
1.232
1.643
2.261
2
2.890
2.905
3.725
1
5.779
5.811
Table 12: Cv Pressure Factors
Содержание Mass-Flo 1179A
Страница 3: ...116527 P1 Rev E 3 99 MKS Type 1179A and 2179A Mass Flo Controller and Type 179A Mass Flo Meter...
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Страница 10: ...List of Figures and Tables viii...
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