| Product
Description> Control Valve 1 2
3 4 5
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III Main Terms of Control Valve
1¡¢Cv flow coefficient
Under regulated condition, that is, differential pressure of two
ends of the valve is 0.1MPa and medium density is 1g/cm3,
flow calculated as m3/h or t/h passing through control
valve in specified travel.
2¡¢Inherent flow characteristic
Inherent relationship between relative flow coefficient and corresponding
relative travel.
3¡¢Relative flow coefficient
Ratio of a certain flow coefficient of specified jaw opening and
rated flow coefficient
4¡¢Rated travel
Travel of all opening position regulated
5¡¢Rated valve capacity
Under regulated experimental pressure condition, flow of experimental
liquid passing through rated travel of control valve
6¡¢Leakage
Under regulated experimental condition, flow of experimental liquid
passing through the valve when it is at shutting position.
7¡¢Downward
When signal pressure increases, handspike moves down as Downward.
8¡¢Upward
When signal pressure increases, handspike moves up as Upward.
IV Cv Value Calculation Formula
This formula takes control valve listed by the manual for example,
generally are water control valve of boiler
In the formula£ºQ¡ªmax. flow m3/h
G¡ªspecific gravity£¨water=1.15¡æ£©
P1¡ªinlet pressure bar
P2¡ªoutlet pressure bar
¡÷P=P1-P2bar
Note£ºCv=1.17Kv Kv is the code of flow coefficient used traditionally
of control valve of our country.
V Leakage Grades of Control Valve
| Leakage Grade |
Max. Leakage of the Base |
Note |
| Grade ¢ñ |
¡ª¡ª |
|
| Grade ¢ò |
0.5% of Rated Capacity |
Double-base |
| Grade ¢ó |
0.1% of Rated Capacity |
Double-base¢Ù |
| Grade ¢ô |
0.01% of Rated Capacity |
Single-base |
| Grade ¢õ |
Differential pressure is 0.1MPa
per mm diameter Allowed leakage £¨water£©5¡Á10-12m3/s
| Single-base¢Ú |
Note£º¢ÙFor grade ¢ó, applicable valve
is same as that of grade¢ò, while it has relatively stricter requirements
on valve base and sealant.
¢ÚAdopt taper sealing of single valve base. It's a fully
sealed structure.
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