KEP ES749 - Page 102

ES749 Flow Computer
98
Accelabar Case








Γ⋅⋅
⋅−=
−
fta
w
coefaa
P
h
YY
73.27
1
Where:
a
Y
= General Accelabar gas expansion factor (dimensionless)
coefa
Y
−
= Accelabar gas expansion factor coefficient (dimensionless)
w
h
= Differential pressure (inches H
2
O @ 68°F)
fta
P
= Flowing Accelerator Throat Pressure (psia)
= Flowing throat pressure in psig + atmospheric pressure in psi
Γ = Isentropic Exponent for a real gas or steam
Accelabar
Size
coefa
Y
−
3”
0.7432
4”
0.6986
6”
0.6865
8”
0.6407
10”
0.6095
12”
0.5891
7.3.11
Expansion Factor
Computation for
Square Law
Flowmeters
(Continued)
For 1 inch Accelabar Body









 

fta
w
a
P
h
Y
73.27
5890.9824.
Where:
a
Y
w
h
ft a
P
= Accelabar gas expansion factor (dimensionless)
= Differential pressure (inches H
2
O @ 68°F)
= Flowing Pressure in Accelabar Throat (psia)
= Flowing pressure in psig + atmospheric pressure in psi

= Isentropic Exponent for a real gas
Γ = Isentropic Exponent for a real gas or steam
For 3 inch to 12 inch Accelabar Body









 

fta
w
a
P
h
Y
73.27
5890.9824.
Where:
a
Y
w
h
ft a
P
= Accelabar gas expansion factor (dimensionless)
= Differential pressure (inches H
2
O @ 68°F)
= Flowing Pressure in Accelabar Throat (psia)
= Flowing pressure in psig + atmospheric pressure in psi

= Isentropic Exponent for a real gas
Γ = Isentropic Exponent for a real gas or steam
For 2 inch Accelabar Body












fta
w
a
P
h
Y
73.27
.5850.9730







