• SPECIAL TOPIC: POWER GENERATION •
A practical approach to selecting stainless
There are some similar opportunities and challenges in the use of various stainless steels for pumps, valves, filters, and other components in a combined cycle gas turbine power plant. Stainless steel suppliers should review the gas turbine process as they would any critical system design effort. The goal is to provide the best overall performance from the combination of materials and operating conditions.
• By Robert McIlvaine, The McIlvaine Company
Stainless steel plays a critical role in combined cycle power plants( CCPP), particularly in valves, pumps, and filtration systems, where reliability under high temperature, high pressure, and corrosive conditions is essential. A combined cycle plant integrates a gas turbine, a heat recovery steam generator( HRSG), and a steam turbine, along with cooling and water treatment systems. Across these systems, stainless steel is selected primarily for its corrosion resistance, mechanical strength, resistance to thermal fatigue, and long service life, all of which contribute to plant efficiency and reduced maintenance downtime.
In valve applications, stainless steel is widely used in high-temperature and high-pressure steam systems within the HRSG and steam cycle. Main steam stop valves, control valves, safety relief valves, and feedwater control valves must withstand steam temperatures that can exceed 500 ° C and pressures above 100 bar. Austenitic stainless steels such as 304 and 316, as well as cast equivalents like CF8M, are commonly employed due to their strength and resistance to oxidation and scaling at elevated temperatures.
In more aggressive environments, such as those involving chlorides or higher mechanical stress, duplex stainless steels are preferred because they offer greater strength and improved resistance to stress corrosion cracking. In cooling water and condensate systems, where exposure to dissolved oxygen and chlorides increases corrosion risk, 316 or duplex grades are often selected to ensure durability.
Stainless steel is equally important in pump construction, particularly in boiler feedwater pumps, condensate extraction pumps, and cooling water pumps. Boiler feedwater pumps operate under high pressures and elevated temperatures, demanding materials that resist both corrosion and cavitation. Martensitic stainless steels such as 410 are frequently used for pump shafts due to their high strength and wear resistance, while 316 or duplex grades are used for casings and impellers in corrosive environments.
In condensate systems, where oxygen-induced corrosion can occur, stainless steel components provide
42 Stainless Steel World Americas | June 2026 | ssw-americas. com