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阀门口径分类标准
通径在各国、各行业标准中都各有解读。公称通径是一个圆整数它和实际通径不完全相同,它以不同形式的阀门和不同公称压力、不同规格尺寸来划分为缩径、不缩径及全通径、流通直径。我国按GB/T12237、GB/T12238、GB/T7746来执行。
美国的通径划分。按美国国家标准ANSI.B16.1；美国工程师协会ASME.B16.34；美国石油协会AP16D；标准以不同的压力规定不缩径的最小流通直径。
英国的通径体系划分以BS5351规定了球阀、通孔阀和不同的压力等级划分最小流通直径。
日本的通径体系划分以JIS.2001规定了通用阀门、船用、室外下水道通用，以不同的压力等级划分流通直径，以我国标准为例。 |
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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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钢制球阀阀体的最小流道直径 The Minimum Flow Diameter
(GB/T12237-1989)(mm) |
公称通径
DN
Nominal Diameter
|
阀体的最小流道直径 The minimum Flow Diameter |
缩径 Reduced Bore |
不缩径 Non-Reduced Bore |
公称压力/MPA
Nominal Pressure |
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 |
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