6.2.2 Design forces and stresses
The main forces acting on condensers are shown in Fig 4.23 for various condenser configurations.
As can be seen from Fig 4.23, the largest single force which ultimately affects the design of the condenser shell is that which results from the vacuum, Fv. In addition to the forces illustrated in Fig 4.23, there are external loads which are also taken into consideration. These include forces resulting from various connections, such as CW connections to the water-boxes, and operational loads of the condenser structure which must be considered when designing the LP turbine mountings and support foundations. These latter loads are of particular importance in the design of integral and side-mounted condensers, where structural stability is necessary to secure turbine alignment. Design stresses for the structures are given in BS1501: 1964 . In practice, however, these stress levels are rarely realised, since the plate thicknesses are usually optimised well within the limits of stress to satisfy minimum deflection criteria, and to comply with the economics of manufacture.