The misalignment issue at DN 65
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Dear colleagues, for the large outer diameter series, the pipe we use with DN65 has an outer diameter of 76.1 mm, while the fittings have an outer diameter of 73 mm. When the thickness of the pipe and the fittings is the same, the misalignment amount is 1.55 mm. DN65 is generally not chosen for this purpose; however, if it is used anyway and the above problems occur, how do you solve this issue of misalignment, based on your experience?
DN generally refers to the nominal diameter according to German standards; it corresponds to an outer diameter of OD 73. Chinese standards do not use this notation
In China, specification 73 is rarely used; other specifications such as 114.3, 168.3, and 508 are much more common. Only specification 73 is seldom utilized. Although we have these specifications in stock, it’s still necessary to confirm which one is required before placing an order, as some applications demand American-standard fittings, but the steel pipes used may not necessarily be of the American standard 73 type. Therefore, specification 76 is often used instead. For these two dimensions, it’s better to avoid them and simply use different fittings
This is the difference between the American system and the European system
When making design choices, one is not familiar with the standards. . The series of pipe fittings isn’t clear; please write it down clearly. . The pipe has an outer diameter of 76 mm, so the fitting should be from the DN65 II series. .
Hehe, this diameter is quite good; most steel pipes can be welded to it. There is just a step issue. In the case of pipes with a DN350 diameter, if the pipe series and the diameter series are mismatched, and the wall thickness of the pipe is too thin, welding will not be possible. For American standard series, it’s 355.6, while for Chinese standard series it’s 377 – there’s a difference of 22 mm in outer diameter. With a thinner wall thickness, the inner diameter of 377 is larger than that of 355.6, so it can be inserted directly.
Yeah, it can all be treated as socket welding
This answer was also rated as the best answer. Who gave it that rating? Do we still need a face! ! !
That’s the theory, but in China, procurement and design teams don’t pay any attention to this at all. When our manufacturers ask about the pipe diameter, whether it’s according to Chinese standards or American standards, the procurement or design teams will mention DN followed by a number; they don’t use DN for German standards, nor do they use inches for American standards.
I don’t know. . . Who rated it? . Please cancel. . . I’m farting here. .