Sigma Inc. is a major supplier of valves to the power generation industry. Sigma’s primary focus is dedicating commercial grade items for nuclear safety related service, as well as supplying forged and cast valves from our large stock of inventory located in Charlestown, Indiana. We excel in supplying valves with special physical characteristics and documentation requirements. Sigma also supplies other power plant items required to fill an immediate critical need. Sigma has earned a superior reputation for supplying quality power plant components to the power industry for the past 15 years. Sigma is a Certified Women’s Business Enterprise (WBE).