Replacement Valves to Eliminate Leakage Problems at Will County

Of all power plant valve applications, that of the boiler feedpump recirculation valve is perhaps the most severe. The recirculation valve is required to remain leak tight for long periods of time, because leakage will decrease the efficiency of the plant through direct energy loss.

This was the case with the existing valves at Unit 3 of the Will County Station in Illinois . The high pressure recirculation valves were suffering severe leakage problems. Will County chose to replace the three existing valves with CCI 3-in (76-mm) high pressure recirculation valves with design pressures up to 3400 psig (234 BarG), mass flow rate of 150,000 lb/hr (68 mt/hr), and operating temperatures designed up to 350 F (180 C). These valves will incorporate CCI’s DRAG® technology, where each disk in the stack has a multitude of tortuous flow channels, and each channel is independent of adjacent channels or disks. Thus each disk’s flow remains constant, regardless of the position of the plug once the opening is uncovered. This is important in the recirculation application, since flow must be controlled during a very high pressure drop to prevent costly energy loss.

Published in SOLUTIONS Fall 2001