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球形止回阀，截止止回阀，提升式止回阀的流量特性曲线
Characteristic Flow Curves for Globe Stop, Stop-Check, Lift-Check Valves
小于全开状态的估计流量系数Cv
Estimating Cv For Less Than Fully Open Valves |
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图2
球形止回阀，截止止回阀和提升式止回阀
Figure 2
Globe Stop, Stop-Check and
Lift-Check Valves
压力密封T形球形止回阀，截止止回阀和提升式止回阀
阀全开状态下的流量系数Cv
Pressure Seal T-Globe Stop,
Stop-Check and Lift-Check Valves FULL OPEN Cv |
阀门通径
Valve Size |
压力等级
Pressure Class |
| 900 |
1500 |
2500 |
21/2
3
4
6
8
10
12
14 |
90
105
195
455
800
1250
1820
2205 |
65
95
170
395
695
1085
1580
– |
45
65
105
265
470
750
1100
– |
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压力密封Y球形止回阀，截止止回阀和提升式止回阀
阀全开状态下的流量系数Cv
Pressure Seal Y-Globe Stop,
Stop-Check and Lift-Check Valves FULL OPEN Cv |
阀门通径
Valve Size |
压力等级
Pressure Class |
| 600 |
900 |
1500 |
2500 |
8
10
12
14
16
18
20
24 |
2025
3025
4600
4300
7650
7325
11800
16450 |
1750
2725
3825
3650
6000
5825
9125
13500 |
1750
2725
3825
3650
6000
5825
9125
13500 |
1175
1875
2650
4075
3775
6625
6225
9050 |
表中所列流量系数仅适用于全开状态下的阀门。不是全开状态的流量系数可以采用适用于提升式阀瓣止回阀和截止阀的流量特性曲线进行估算。不建议将闸阀用在节流应用中。
The flow coefficient (Cv) listed in the tables apply to fully open valves only. Flow coefficients at other than fully open may be approximated by use of the characteristic flow curves for tilting disc check and globe valves. Gate valves are not recommended for throttling service.
例：
DN300，压力等级Class 900的美国太平洋压力密封截止阀在开气度为1/4时的流量系数是多少？
EXAMPLE:
What is the Cv of a 12 inch Class 900 Pacific pressure seal globe valve 1/4 open? |
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图3
Y形球形止回阀，截止止回阀和提升式止回阀
Figure 3
Y-Globe Stop, Stop-Check and
Lift-Check Valves
压力密封缩喉管球形止回阀，截止止回阀和提升式止回阀
阀全开状态下的流量系数Cv
Pressure Seal Venturi Globe Stop,
Stop-Check and Lift-Check Valves FULL OPEN Cv |
阀门通径
Valve Size |
压力等级
Pressure Class |
| 900 |
1500 |
2500 |
8 x 6 x 8
10 x 8 x 10
12 x 10 x 12
14 x 12 x 14
16 x 14 x 16 |
450
770
1215
1775
2125 |
390
690
1055
1550
– |
260
465
745
1070
– |
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压力密封缩喉管Y球形止回阀，截止止回阀和提升式止回阀
阀全开状态下的流量系数Cv
Pressure Seal Venturi Y-Globe Stop,
Stop-Check and Lift-Check Valves FULL OPEN Cv |
阀门通径
Valve Size |
压力等级
Pressure Class |
| 600 |
900 |
1500 |
2500 |
8 x 6 x 8
10 x 8 x 10
12 x 10 x 12
14 x 12 x 14
16 x 14 x 16
18 x 16 x 18
20 x 18 x 20
22 x 20 x 22
16 x 24 x 26 |
1100
1925
2875
4375
4075
7250
6950
11200
15850 |
1000
1675
2600
3650
3450
5700
5525
8675
12825 |
1000
1675
2600
3650
3450
5700
5525
8675
12825 |
650
1125
1775
2525
3875
3575
6300
5925
8600 |
解：
从上列流量系数表中得到，DN300，压力等级Class 900截止阀在全开状态下的Cv是1820。
SOLUTION:
From the flow coefficient table above, the fully open Cv for a 12 inch, Class 900 globe valve is 1820.
查询图2，全开状态的1/4时阀门的比率是52%.
Consulting Figure 2, the percent of fully open Cv at 1/4 valve open is 52%.
因此计算1/4全开的流量系数Cv为：
0.52 x 1820 = 946.
The Cv at 1/4 open is then computed as:
0.52 x 1820 = 946.
