What does the pressure rating PN refer to, kilograms or MPa? Why is this change made?
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Taking version HG20592-97 as an example, the pressure rating specified is still PN1.6MPa. But in the HG20592-2009 version, the pressure rating became PN16, without the “Mpa” suffix. This has led to a significant confusion: in many places, only PN16 is indicated, and it’s not clear whether this refers to 16 kilograms or MPa. Looking at DIN_2696-1999 again, it mentions PN400; since it’s in German, it’s even harder to determine whether this refers to a standard of 400 MPa or 400 kilograms
If only PN16 is written, it refers to 1.6 MPa; if PN16MPa is written, it means 16 MPa. Generally, no unit is indicated, and the unit is kilograms – for example, PN40 means 40 kilograms
The current values are PN63 and PN400; conventionally, these are understood to mean 6.3 MPa and 40 MPa respectively, but the data shows 63 MPa and 400 MPa, which is confusing
It’s actually just a difference between the units Mpa and bar; different standards may use different units. In DIN_2696-1999, the unit used is bar, and on the first page there is a range specified – the rated pressure ranges from 63 bar to 400 bar.
Now it’s all PN16, which means 16 kg, 16 bar, or 1.6 Mpa
The number in the PN range represents kilograms (BAR)
It is said that in ancient times it was PN16=1.6MPa, during the medieval period it was changed to PN1.6=1.6MPa, and in modern times it has been changed back to PN16=1.6MPa
However, all available literature indicates that the DIN2696 standard is applicable to 400 MPa
DIN2696-1999 specifies that the applicable pressure range for this standard is 63 bar to 400 bar. Other literature citations will probably only state that it is suitable for PN63-PN400.
Good heavens, someone would actually ask such a question (saying it would cause misunderstandings). I guess only someone like you, who’s just starting out, would be capable of causing misunderstandings. 20592 still uses the one from 97 actually