The tempering process is carried out in this type of 'pizza' oven. It is necessary to make the cast bronze workable, which is brittle like glass. While this is done solely because the roto-cast cymbal couldn't be worked on otherwise, some UFIP cymbal lines and types are tempered again later in the process for reasons of sound.
For instance the Experience series is tempered more than once to achieve the aged, more mellow sound found in old cymbals. Tempering happens at much lower temperatures than the 1200°C needed to cast bonze. The cymbals are glowing dark red when they come out. The light blue flame somehow didn't get on the photo.