閥門標準
閥門口徑分類標準
通徑在各國、各行業標準中都各有解讀。公稱通徑是一個圓整數它和實際通徑不完全相同,它以不同形式的閥門和不同公稱壓力、不同規格尺寸來劃分為縮徑、不縮徑及全通徑、流通直徑。我國按GB/T12237、GB/T12238、GB/T7746來執行。
美國的通徑劃分。按美國國家標準ANSI.B16.1；美國工程師協會ASME.B16.34；美國石油協會AP16D；標準以不同的壓力規定不縮徑的最小流通直徑。
英國的通徑體系劃分以BS5351規定了球閥、通孔閥和不同的壓力等級劃分最小流通直徑。
日本的通徑體系劃分以JIS.2001規定了通用閥門、船用、室外下水道通用，以不同的壓力等級劃分流通直徑，以我國標準為例。
There are different understandings for DN in different countries. It is an integer which is a little different from practical diameter.It is divided into reduced bore, non-reduced bore,full bore and flow diameter by different valve, nominal Preassure, spec sizes. It is carried out by GB/T12238、GB/T7746 in China.
American standard.ANSI.B16.1;ASME.B16.34;AP16D.
Inch system is applied to BS5351.
Japanese diameter system conform to JIS.2001.
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鋼制球閥閥體的最小流道直徑 The Minimum Flow Diameter | |||
|
公稱通徑 |
閥體的最小流道直徑 The minimum Flow Diameter | ||
|
縮徑 Reduced Bore |
不縮徑 Non-Reduced Bore | ||
|
公稱壓力/MPA | |||
|
1.6. 2.5. 4.0. 6.4. |
10 | ||
|
10 |
- |
9 |
9 |
|
15 |
9.5 |
12.5 |
12.5 |
|
20 |
12.5 |
17 |
17 |
|
25 |
17 |
24 |
24 |
|
32 |
23 |
30 |
30 |
|
40 |
28 |
37 |
37 |
|
50 |
36 |
49 |
49 |
|
65 |
51 |
64 |
64 |
|
80 |
57 |
75 |
75 |
|
100 |
76 |
98 |
98 |