I have a question regarding the steel stamp on the butterfly valve body
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Valves such as ball valves and gate valves. Those marked 2\" are generally of the American standard, while those marked DN50 are usually of the Chinese standard. I recently bought a batch of butterfly valves, some meeting national standards and others meeting American standards. I only realized it after it arrived. . How can both national and international standards be indicated on a butterfly valve? Or are they selling us chargers that meet domestic standards but are designed for American standards? Is there anyone with experience in this industry who can help clarify this? I’m not sure whether there are differences in the valve parameters related to dimensions for butterfly valves between American standards and Chinese standards. Can it be found through GB and ASME? ? Or does no manufacturer have a standard one?) Thank you so much
As a valve manufacturer, the so-called American standards and national standards you mentioned actually refer to the American standard and the European standard, that is, the PN and Class classifications. The only difference between them is in the pressure ratings; accordingly, the sizes of the valve connection ends also differ. The choice between PN and Class is mainly determined by the size of the pipeline, with no other differences. There is no such thing as national standards being passed off as American standards, nor is it true that American standards are of better quality than national standards. Everything is determined based on the customer’s requirements and the installation conditions on site!
It’s not the case that a marking of “2” necessarily means it’s a US standard; what matters is the pressure. Is the pressure indicated on the label 150 LB? If so, then it’s definitely the US standard. At a reference temperature of 260 degrees, 150 LB is approximately equal to 2.0 MPa. Looking at the rubber-lined center-line butterfly valve in your image, the valve body follows national standards, which is why it is labeled as DN350. I don’t think there’s a significant difference in dimensions; different manufacturers produce valves with varying specifications. There are also manufacturers that specialize in producing valves according to American standards, and in such cases the valve body will be labeled as 14”
It’s not the case that a marking of “2” necessarily means it’s a US standard; what matters is the pressure. Is the pressure indicated on the label 150 LB? If so, then it’s definitely the US standard. At a reference temperature of 260 degrees, 150 LB is approximately equal to 2.0 MPa. Looking at the rubber-lined center-line butterfly valve in your image, the valve body follows national standards, which is why it is labeled as DN350. I don’t think there’s a significant difference in dimensions; different manufacturers produce valves with varying specifications. There are also manufacturers that specialize in producing valves according to American standards, and in such cases the valve body will be labeled as 14”
I would have forgotten to mention it if you hadn’t asked. . The strangest thing about this valve is this: the protruding mark on the upper half of the valve body indicates 150lb, while on the back side of the lower half of the valve body, at DN350, the mark indicates PN16/20. This is what puzzles me the most. .
For this butterfly valve, the pressure rating is indicated as 150LB on the protruding part in the upper half; on the lower half, at the back of the DN350 marking, it is indicated as PN16/20. The valve core, located in between, has a rating of 14. . That’s why I think it’s so chaotic.
For this butterfly valve, the pressure rating is indicated as 150LB on the protruding part in the upper half; on the lower half, at the back of the DN350 marking, it is indicated as PN16/20. The valve core, located in between, has a rating of 14. . That’s why I think it’s so chaotic.
Yes, I just said it – at 260 degrees, 150 LB is approximately equal to 2.0 MPa, which corresponds to PN20. So the valve body used is appropriate
:Are the spare parts supplied by manufacturer L US standard, EU standard, or universal? !
Refer to the nameplate. The right to interpret the markings on the valve housing belongs to the manufacturer. Both domestic and international standards require that various parameters be indicated on the valve housing, but they do not specify how to do so. You can make a rough guess based on *habit, but strictly speaking it’s not reliable. That is just a quality traceability mark. The large components on the valve require further processing. The same blank can be used for different standards. The markings on the valve housing are applied during the production of the blank.