Valves and flow equipment for the paper industry

Paper production plants operate with steam, condensate, process water, hot water, cooling water, compressed air, chemical solution and auxiliary fluid networks. Valve selection is based on pressure, temperature, fluid type, presence of fibres or solids, operating frequency and the maintenance requirements of the installation.

Paper production requires controlled flow and stable temperature in stock preparation, cleaning, sheet forming, pressing, drying, coating, cutting and water treatment processes. Steam and condensate networks are directly connected to drying cylinders and heat exchangers, while water and chemical circuits require material compatibility and cleanability.

Typical applications

• Steam networks on drying cylinders, heat exchangers and thermal processes.
• Condensate and drainage lines from headers, cylinders and steam pipework.
• Process water, washing, cooling, recirculation and cleaning circuits.
• Chemical solution lines for pulp treatment, cleaning, coating and pH control.
• Compressed air networks for pneumatic actuators, instruments and auxiliary equipment.
• Wastewater treatment, water recovery and drainage systems.
• Auxiliary circuits on tanks, pumping stations, heat exchangers, presses and cutting units.

Equipment selection criteria

• Operating pressure, design pressure and valve differential pressure.
• Operating temperature and variations during start-up, shutdown or cleaning.
• Material compatibility with steam, condensate, water, pulp, chemical solutions or auxiliary fluids.
• Possible presence of fibres, suspended solids, deposits or corrosive components.
• Required flow rate and allowable pressure drop.
• Isolation, control, non-return, relief or overpressure protection function.
• Seat, stem and connection tightness requirements.
• Operating frequency and need for connection to PLC, DCS or local automation system.
• Access for inspection, cleaning, maintenance and replacement of internal parts.

Indicative equipment

• Isolation valves for steam, water, condensate, air and auxiliary fluids.
• Control valves for flow, pressure, temperature or level regulation.
• Pressure reducing valves and pressure regulators for steam, air and water networks.
• Check valves for pump protection and backflow prevention.
• Safety and relief valves for boilers, vessels, headers, heat exchangers and pipework.
• Steam traps and condensate management equipment in steam lines.
• Line strainers for protection of control valves, pumps, nozzles and instruments.
• 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, flow rate, pressure, temperature, presence of fibres or solids, cleaning conditions 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.