Do flanges and valves come in large outer diameter and small outer diameter versions?
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Are flanges and valves classified into those with a large outer diameter and those with a small outer diameter? For example, if a flange is DN100 PN25, does that mean it follows the European standard and belongs to the series with a small outer diameter, requiring pipes with an outer diameter of 108? On the other hand, DN100 150LB flanges follow the American standard and require pipes with an outer diameter of 114. Is that how it works?
It’s not the pipe that fits the flange; it’s the flange that adapts to the pipe. First, determine the standard and regulatory requirements for the pipes
The steel stamp on the flange indicating PN refers to the national standard series, right? And the CLASS value printed there indicates the American standard series. Do they each fit with pipes of Series A or Series B?
The US standard has one series, while the European system has two series
No, the CL series of American standards, ASME B 16.5 and HG/T 20615, refer to weekly system flanges, while HG/T 20592 refers to European system flanges； Whether the pipe has a large or small outer diameter should be indicated with A series (large diameter) or B series (small diameter) behind the flange
Isn’t the American standard for pipes the A series with a larger outer diameter, while the European standard is the B series with a smaller outer diameter? Is that right? I’m a bit confused :(
American standards are all in Series A, while Chinese standards are divided into Series A and Series B
HG/T 20615 is a combination of American standards and national standards; therefore, those based purely on American standards fall under the A series, while the variants belong to both the A and B series
Is the A series of national standards the same as the A series of American standards?
National Standard Series A is equivalent to the American Standard series; the American standard does not have Series A or B