５．２ Calculating The Nominal Size; ６．１ Piping Example - Yoshitake DP-10 Series Instruction Manual

５．２ Calculating the Nominal Size
■Formula for Cv value calculation
《For steam》
When
Ｐ ＞
2
Cv ＝
138
When
Ｐ ≦
2
Wk
Cv ＝
120
《For liquid》
0.365
Cv ＝
Ｃｖ ： Cｖ value of the nominal size
W ： Max. steam flow rate [kg/h]
Ｑ ： Max. gas flow rate
Ｖ ： Max. liquid flow rate [m
ｋ ： １＋０.００１３×｛Super-heat Steam Temp. [℃] －Saturated Steam Temp. [℃]｝
G ： Specific gravity (For gas, relative to air; For liquid, relative to water)
■Cv value
Nominal size
Piston type
Diaphragm type
* In case of inlet/outlet pressure differential is less than 0.01MPa, Cv value shown
in brackets should be adapted.
６．Installation
６．１ Piping Example
Pressure
Gauge
Inlet
* When the valve is used at 0.1MPa or less, mount the valve to the horizontal piping
and the coil being at the top.
Ｐ
1
2
Wk
Δ P （P ＋P ）
1 2
Ｐ
1
2
P
1
V G
ΔP
3
[m /h(Normal condition)]
3
/h]
10A 15A
3.1 4.9
3.0 4.4
(1.2) (1.7)
By-pass
Valve
《For air》
When
Ｐ ＞
2
Cv ＝
2940
When
Ｐ ≦
2
Q
Cv ＝
P
１
P
２
Δ Ｐ ： Ｐ
20A 25A 32A
8.2 12.4 17.7
8.1 11.5 17.0
(3.2) (4.6) (6.8)
Solenoid Valve
Strainer
By-pass Valve
-10-
Ｐ
1
2
Q
（273＋ｔ） G
Δ P （P ＋P
1
Ｐ
1
2
（273＋ｔ） G
2550 P
1
： Inlet pressure
： Outlet pressure [MPa･A]
－Ｐ [MPa]
１ ２
40A 50A
25.0 33.6
23.3 30.5
(9.3) (12.2)
Pressure Gauge
By-pass
Outlet
Valve
■EPDT-028d■
）
2
[MPa･A]
65A
33.6