Valves and flow equipment for power plants

Power plants operate with steam, feedwater, condensate, cooling water, thermal oil, fuel, compressed air, industrial gas, chemical water treatment and auxiliary fluid networks. Valve selection is based on pressure, temperature, fluid type, differential pressure, operating cycle and equipment protection requirements.

Thermal plants, CHP units, biomass boilers, turbine auxiliary systems and heat recovery installations require a defined function for each valve. Steam and feedwater lines require pressure control and overpressure protection. Condensate circuits require condensate removal and backflow prevention. Cooling and auxiliary fluid networks require stable flow, section isolation and access for maintenance.

Typical applications

• Steam lines on boilers, headers, superheaters, heat exchangers and auxiliary users.
• Feedwater, condensate return, drainage and blowdown lines.
• Cooling water, closed water, treated water and recirculation circuits.
• Thermal oil systems and heat transfer fluid circuits.
• Fuel, industrial gas, nitrogen and compressed air lines.
• Steam pressure reducing stations and auxiliary network pressure regulation.
• Protection systems for boilers, pressure vessels, heat exchangers, pumps and pipework.
• Auxiliary circuits in CHP, biomass and heat recovery units.

Equipment selection criteria

• Operating pressure, design pressure and valve differential pressure.
• Operating temperature, thermal cycles and start-up or shutdown conditions.
• Material compatibility with steam, feedwater, condensate, fuel or chemical media.
• Required flow rate, minimum flow rate and allowable pressure drop.
• Isolation, control, non-return, relief or overpressure protection function.
• Seat, stem and connection tightness requirements.
• Resistance to thermal expansion, vibration, water hammer and load variations.
• Operation requirements from PLC, DCS, SCADA or safety system.
• Access for inspection, section isolation, maintenance and replacement of components.

Indicative equipment

• Isolation valves for steam, water, condensate, fuel and auxiliary fluids.
• Control valves for flow, pressure, temperature or level regulation.
• Pressure reducing valves and pressure regulators for steam, air and industrial gas networks.
• Check valves for protection of pumps, compressors and condensate lines.
• Safety and relief valves for boilers, vessels, heat exchangers and pipework.
• Steam traps and condensate management equipment.
• Line strainers for protection of control valves, pumps, instruments and heat exchangers.
• Separators, air vents and drainage equipment for steam and water networks.
• Pneumatic and electric actuators for remote or automatic operation.

For each application, the line operating data, fluid, pressure, temperature, flow rate, start-up conditions, load variations, available installation length and control system requirements should be reviewed. These data define the valve type, nominal size, pressure class, construction materials, sealing arrangement and suitable actuation method.