DN is a nominal designation, not a guarantee of flange compatibility. Compare the actual drawing, bolt circle, hole count, facing and gasket requirements.
Do not treat PN and ASME Class as directly interchangeable. Allowable pressure depends on temperature, material group and the applicable standard. Request the pressure-temperature table for the selected configuration.
For a replacement RFQ include face-to-face dimensions, flange standard and material requirements alongside DN, pressure and temperature. We check compatibility before proposing an alternative.