５．２ Selection Formula For Nominal Size - Yoshitake GD-200 Series Manual

５．２ Selection Formula for Nominal Size
・Cv value
Nominal Size 15A
Cv value 2.5
・Cv Value Calculation Formula
< For Gas >
In case of
=
C
V
< For Liquid >
=
C
V
・Viscosity correction Formula
Find the Max. Flow rate (V) when the viscosity is ignored.
=
V
. 0
And find the viscosity index of Iv.
=
I
V
Find the value of K from the value of Iv, found through the above formula,
with the viscosity correction curve. The calculated Max. flow rate divided
by the value of K is the corrected value.
Compensated Max. flow rate Ｖ'＝Ｖ／Ｋ（m
Viscosity Correction Curve
Fig.8
20A 25A
4 5
p
>
1
p
2
2
( )
+
Q 273 t G
( )
∆ +
2940 P P P
1 2
. 0 365 V G
∆
P
⋅ ∆
Cv P
⋅
365 G
1
⎛ ∆
⎞ 1
72780 P
4
⎜ ⎟
2
V
⎝ ⎠
M G
cst
Table 5
32A 40A 50A
8 12 16
P : Inlet pressure [MPa･A]
1
P : Reduced pressure [MPa･A]
2
ΔP: P - P
1
G : Specific gravity
(Gas : Specific gravity relative to air
Liquid : Specific gravity relative to
water)
V : Max. liquid flow rate [m
Q : Max. gas flow rate [m
t : Temperature [℃]
Cv : Cv value of the nominal size
Ｉv: Viscosity index
Mcst: Viscosity {cSt}
-7-
65A 80A 100A 125A 150A
28 36 68
≤
In case of
p
2
(
+
Q 273 t
=
C
V
2550 P
1
3
/h）
[MPa]
2
3
75 108
p
1
2
)
G
3
/h]
/h(Normal state)]
■EPDT-096b■