阀座端口流速计算
Calculating Seat Port Velocity
下列公式可以用来计算任何阀门的阀座流速:
The following formulas can be used to calculate
seat port
velocity in any valve:
流量(磅/小时): 流速: (英尺/秒)= |
F( )2 |
|
25A |
|
Flow (lbs/hr): vel:
(fps) = |
F( )2 |
|
25A |
|
流量(加仑/分钟): 流速: (英尺/秒)= |
|
Flow (GPM): vel:
(fps) = |
|
F |
= |
流量(磅/小时) |
F |
= |
flow (lbs/hr) |
![](img/0260_2.gif) |
= |
比容积的平方根 |
![](img/0260_2.gif) |
= |
square root of specific volume |
A |
= |
阀座端口面积 (英寸2) |
A |
= |
seat port area (in2) |
Q |
= |
流量 (加仑/分钟) |
Q |
= |
flow (gpm) |
例:
DN300型号58809 (压力等级Class 900)止回阀,流体介质为温度500 oF,压力200 PSIG的蒸汽,流速为90,000磅/小时,求阀座端口的流速?
Example:
What is the seat port velocity in a 12" Figure 58809 (Class 900)
check valve with a flow rate of 90,000 lbs/hr of steam at 500 oF
and 200 PSIG?
解:
从蒸汽表得 为1.61,从阀座端口面积表A得阀座端口面积为78.5英寸2。
Answer:
From the steam tables is
1.61, and from the seat port area table A is 78.5 in2.
流速: (英尺/秒)= |
F( )2 |
|
25A |
|
= |
|
= 118.8 英尺/秒 |
Vel (fps) = |
F( )2 |
|
25A |
|
= |
|
= 118.8 fps |
例:
DN300型号180 (压力等级150)旋启式止回阀,流体介质为温度500oF,压力200 PSIG的蒸汽,流速为90,000磅/小时,求阀座端口流速?
Example:
What is the seat port velocity in a 12" Figure 180 (Class 150)
Swing Check Valve with a flow rate of 90,000 lbs/hr of steam at 500oF
and 200 PSIG?
解:
查表得 为1.61,A为
113.1英寸3.
Answer:
From the tables is
1.61 and A is 113.1 in3.
流速: (英尺/秒)= |
F( )2 |
|
25A |
|
= |
90,000 (1.61)2 |
|
25 (113.1) |
|
= 82.5英尺/秒 |
Vel (fps) = |
F( )2 |
|
25A |
|
= |
90,000 (1.61)2 |
|
25 (113.1) |
|
= 82.5 fps |
局限性
LIMITATIONS
流速公式在下列条件下无效:
Velocity formulas are not valid under the following
conditions:
- 对于可压缩性流体,如果压降超过进口压力的一半。
For compressible fluids, where pressure drop exceeds
half the inlet pressure.
- 对于不可压缩性流体,如果压降产生空穴或闪蒸。
For non-compressible fluids, where pressure drop
causes cavitation or flashing.
- 对于双相流体,如蒸汽-水混合流体。
For dual-phase flow such as steam-water mixtures.
注意
NOTE
在确定止回阀通径时,最适宜的工作流速应该位于这些范围内:
When determining sizing for check valves, the
optimum operating velocities should fall within these ranges:
BB旋启式止回阀:55 至115 或135 至240![](img/0260_2.gif)
BB截止止回阀:40 至120 ![](img/0260_2.gif)
PS提升式阀瓣止回阀:55 至200
PSY形止回阀:148 至200 ![](img/0260_2.gif)
BB Swing Check Valves - 55
to 115 or 135
to 240![](img/0260_2.gif)
BB Stop Check Valves - 40
to 120 ![](img/0260_2.gif)
PS Tilt Disc Check Valves - 55
to 200 ![](img/0260_2.gif)
PS Stop Check Valves - 40
to 180![](img/0260_2.gif)
PS Y- Stop Check Valves - 148
to 200 ![](img/0260_2.gif)
|
|
阀座端口面积“A”(英寸2)
适用于螺栓阀帽阀门
SEAT PORT AREA "A" FOR BOLTED
BONNET VALVES (in2) |
阀门通径
Valve Size |
压力等级
Pressure Class |
150 |
300 |
600 |
900 |
1500 |
11/2
2
21/2
3
4
6
8
10
12
14
16
18
20
24
30
36 |
1.8
3.1
4.9
7.1
12.6
28.3
50.3
78.5
113.1
137.9
182.7
233.7
291.0
424.5
671.9
969.0 |
1.8
3.1
4.9
7.1
12.6
28.3
50.3
78.5
113.1
137.9
182.7
227.0
283.5
424.5
672.0
942.0 |
1.8
3.1
–
7.1
12.6
28.3
48.7
74.7
108.4
130.2
170.9
213.8
261.6
380.1
590.9
851.2 |
1.8
3.1
4.9
6.5
11.8
26.0
44.2
71.0
100.0
117.9
–
–
–
–
–
– |
1.5
2.8
4.0
6.0
10.3
22.7
38.5
60.0
84.5
101.6
–
–
–
–
–
– |
阀座端口面积(英寸2)
适用于压力密封闸阀,截止阀,提升式阀瓣止回阀
SEAT PORT AREA FOR PRESSURE SEAL GATE,
GLOBE, TILT DISC CHECK VALVES (in2) |
阀门通径
Valve Size |
压力等级
Pressure Class |
600 |
900 |
1500 |
2500 |
21/2
3
4
6
8
10
12
14
16
18
20
24 |
5.4
5.4
9.6
23.2
39.9
61.0
88.7
–
–
173.8
–
310.25 |
5.9
5.9
10.3
21.7
37.7
58.4
80.5
97.2
125.2
156.7
198.0
287.3 |
3.3
4.9
8.3
18.9
31.9
48.7
69.0
82.5
108.4
137.9
170.9
247.5 |
2.4
3.6
5.9
12.6
21.7
34.5
47.2
58.2
76.6
97.2
117.9
170.9 |
阀座端口面积(英寸2)
适用于压力密封Y形截止阀
SEAT PORT AREA FOR PRESSURE SEAL Y-GLOBE
VALVES (in2) |
阀门通径
Valve Size |
压力等级
Pressure Class |
900 |
1500 |
2500 |
8
10
12
14
16
18
20
24 |
39.9
61.9
86.6
86.6
135.4
135.4
198.1
302.6 |
39.9
61.9
86.6
86.6
135.4
135.4
198.1
302.6 |
27.2
42.8
60.1
86.6
86.6
135.4
135.4
198.1 |
|