| D－系列尺寸表
－ 英寸/磅 |
| |
端面间距 |
|
重量（磅） |
| 尺寸 |
NPT/BSP |
125# |
250# |
B |
C* |
D |
E** |
NPT/BSP |
法兰 |
| 1/2" |
5-1/8 |
|
|
5-1/8 |
11 |
5-7/8 |
7 |
18 |
|
| 3/4" |
5-1/2 |
|
|
5-1/2 |
11 |
6-1/2 |
7-1/4 |
21 |
|
| 1" |
6-1/8 |
|
|
6-1/8 |
11 |
7 |
7-1/2 |
25 |
|
| 1-1/4" |
8-1/2 |
|
|
7 |
11-7/8 |
8-3/4 |
8 |
45 |
|
| 1-1/2" |
9-1/2 |
|
|
7-1/8 |
11-7/8 |
8-3/4 |
8-1/2 |
55 |
|
| 2" |
9-3/4 |
9-1/2 |
9-5/8 |
7-1/8 |
11-7/8 |
10-7/8 |
9 |
90 |
105 |
| 2-1/2" |
|
10 |
10-5/8 |
8-3/4 |
11-7/8 |
11-3/4 |
9-1/2 |
|
135 |
| 3" |
|
11 |
11-3/4 |
9-1/8 |
11-7/8 |
13-1/4 |
10 |
|
180 |
| 4" |
|
13-3/8 |
13-7/8 |
10-3/8 |
11-7/8 |
14-3/4 |
11 |
|
290 |
| 6" |
|
18-1/8 |
19 |
16 |
12-1/2 |
19-3/4 |
12 |
|
590 |
|
|
|
| HD－系列尺寸表
－ 英寸/磅 |
| |
端面间距 |
|
重量（磅） |
| 尺寸 |
NPT/BSP |
150# |
300# |
B |
C* |
D |
E** |
NPT/BSP |
法兰 |
| 1/2" |
4-3/8 |
|
|
5-1/2 |
11-7/8 |
6-1/2 |
7-3/4 |
18 |
|
| 3/4" |
4-3/8 |
|
|
5-1/2 |
11-7/8 |
6-1/2 |
7-3/4 |
18 |
|
| 1" |
5-3/8 |
|
|
6-1/4 |
11-7/8 |
7 |
7-3/4 |
23 |
|
| 1-1/4" |
7-1/4 |
|
|
7-3/8 |
11-7/8 |
8-3/4 |
8-1/4 |
43 |
|
| 1-1/2" |
7-1/4 |
|
|
7-3/8 |
11-7/8 |
8-3/4 |
8-1/4 |
43 |
|
| 2" |
7-1/2 |
8-1/2 |
9 |
8-1/4 |
11-7/8 |
10-7/8 |
8-1/2 |
65 |
85 |
| 2-1/2" |
|
9-3/8 |
10 |
9 |
11-7/8 |
11-3/4 |
8-1/2 |
|
105 |
| 3" |
|
10 |
10-3/4 |
8-7/8 |
11-7/8 |
13-1/4 |
9-1/2 |
|
145 |
| 4" |
|
11-7/8 |
12-1/2 |
10-7/8 |
11-7/8 |
14-3/4 |
10-1/2 |
|
235 |
| 6" |
|
15-1/8 |
16 |
14-1/8 |
12-1/2 |
19-3/4 |
11-3/4 |
|
470 |
|
|
|
*P5型先导阀：对于尺寸1/2”~1-1/2”，C栏尺寸另加2-1/2’；
对于尺寸2”~6”，C栏尺寸另加5”。
**P5型先导阀：对于所有尺寸，E栏尺寸均另加1-1/2”。
|
|
|
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选型和下定单
“P”型或“P5”压力先导阀
请标明：减压范围
调节阀
请标明：
D系列或HD系列调节阀
调节阀接口尺寸或蒸汽流量及压力
接口尺寸（BSPT或NPT 螺口，PN16 / 125# / 150# / 250# / 300# 法兰）
|
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工作原理
安装压力先导阀用以控制压力先导式减压阀的操作工况。连接在先导阀与减压阀下游管线上的反馈管可反馈压力变化情况。反馈管的压力变化直接作用于先导阀的膜片下。当系统压力达到调节弹簧的压力设定点时，膜片下的压力推动其压紧弹簧向上移动，逐步关闭压力先导阀，当压力先导阀关闭，蒸汽不会再进入减压阀主阀下面的隔膜腔，主阀也随之关闭。当蒸汽压力下降低于其设定值，压力先导阀打开，蒸汽进入主阀隔膜腔，顶起主膜片打开主阀。
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