#109 Corroding stainless steel ball valves are replaced by longer-lasting lined valves.  Problem: A water treatment system at a nuclear power facility in Illinois included a large number of stainless steel valves. Two chemicals were used for descaling condenser tubes. These chemicals were contributing to rapid corrosion of the stainless steel valves. Plant personnel considered more expensive exotic alloy valves but two factors deterred them. First, the expense and second, uncertainty about the ability of those valves to better resist the corrosive effects of the chemicals.  Additional Considerations: Plant personnel wanted to avoid any reduction in flow. Full port valves seemed to provide the answer. They thought that lined valves might provide longer service life. However, plant engineers were concerned that full- port lined valves might be expensive and might not be available in standard face-to-face dimensions. For economy and ease of installation, they felt that standard face-to-face dimensions was an important prerequisite.  Solution: Plant engineers were pleasantly surprised to discover the Tufline fully-lined, full-port ball valve. The valve offered all these features they needed in a compact design with standard (B16.10 regular short-pattern) face- to-face dimensions. The valve price was similar to that of the stainless steel valves previously used. Cast in recesses and machined grooves lock the lining to the valve body and ball. The lining resists blow out. The lining material is unpigmented, virgin PFA.  Result: Half the failing stainless steel valves were replaced with Tufline Ball Valves. The corrosion problems were solved. Various additive chemicals in different concentrations had no affect on the valve lining. After evaluation of valve performance, it was decided to replace the remaining stainless steel valves with the Tufline Ball Valves. Index of all performance report case histories.