Figure 5: Attemperator problems are indicated by downstream thermocouples which detect erratic temperature readings (jagged red, white, and magenta lines at left center of chart).

Temperature control is a big deal in Pittsburg, Texas, where summer afternoons average in the mid-90s and frequently top 100. At AEP/SWEPCO’s J. Robert Welsh Power Plant, however, the problem ...

The attemperator system installed at a plant designed for baseload may exhibit much different operation when cycled. A functional field test often proves prior factory test settings to be inaccurate.

Attemperator designs with flow-control elements in the steam path—the multinozzle probe style shown in Figure 2, for example—are particularly susceptible to such damage.