DIN flange impact testing exemption for PED compliant vessel

[PaulHalverson]

Hello everyone,

I'm designing a PED compliant heat exchanger with a MDMT of -20° F and am wondering if anyone familiar with the PED specifications knows whether or not DIN flanges are exempt from impact testing in the same way that ANSI flanges are exempt per UCS-66(c), and if this is the case, what PED spec allows it?

I'd appreciate any insight anyone can offer.

 

[XL83NL]

DIN flanges may or may not be exempt. PED doesnt care if it's DIN, JIS, ASME, or whatever. It does however look at material type. See guideline G-17, and PED Annex I para 7.5.

In short, it matters if its carbon steel or stainless steel. Since youre referencing UCS-66(c) Im assuming youre using carbon steel. A workaround, whats often done by (at leats the good) mills, is that they include a PED reference on the MTR for carbon steel material, and include the charpy impact test results. If this happens you know if you material meets PED requirements. But do look out if your MDMT is lower than the typical -27 deg C thats on the MTR.

In the end, all you need to do is fullfill ALL essential safety requirements. Easiest is by using a harmonized standard. Another method is by using e.g. ASM VIII Div 1. But using DIN flanges on VIII-1 together with PED is quite the challenge!

PS: are you sure youre using DIN flanges, and not the EN 1092-1 flanges? Din has been replaced with EN 1092-1