Abstract: A rotary mechanical seal with metal bellows having reinforced weld joints. The bellows is formed of a plurality of adjacent annular discs or diaphragms having inner and outer circumferences welded together. A plurality of annular reinforcing rings are provided, each being associated with the welded joint at one circumference of the diaphragms. The associated rings and the circumferences define a weld area. The presence of the reinforcing rings allows for larger and stronger welds along the associated circumferences, which increases the capacity of the seal to withstand operating pressures.