Manual 35018V1
505XT Digital Control System for Steam Turbines
Woodward
100
Figure 3-23. Typical Admission Steam Map
Extraction & Admission Steam Map
Before a turbine’s extraction/admission steam map can be programmed into the control, it must have the
intersection points A, B, & C (refer to Figure 4-6).
If points A & B already exist, the only conversion necessary is the extension of the LP=0 line and the zero
extraction and admission flow line until they cross or intersect (this is Point C for programming). If point A
does not exist, the extension of the LP=100 line and the zero extraction and admission flow line until they
cross or intersect is Point A for programming.
If points B & C do not exist, your map will have to be modified to include points B & C. The LP=0 line will
need to be created. To create the LP=0 line you must know the minimum required steam flow through the
back-end of the turbine. In our example steam map (Figure 4-6) the minimum required flow was 8000 lb/h
(3629 kg/h).