A radial seal assembly is disclosed for a regenerative heat exchanger. The radial seal assembly can include a mount having a first upstanding region and a first arcuate region. Here, the first upstanding region is configured to attach to a diaphragm of the heat exchanger. The radial seal assembly further includes a flexible radial contact or non-contact seal, wherein the seal further includes a second arcuate region. Here, the first arcuate region of the mount is configured to receive the second arcuate region of the flexible seal and securing the flexible seal therein.