Pressure Reduction for Power Plants

Cavitation control in pulp and paper systems

Pulp and paper mills operate demanding liquid systems that often run continuously between planned outages. Boiler feedwater, blowdown letdown, high-pressure shower water, mill service water, condensate, and process-fluid lines can develop cavitation where pressure drop is concentrated, especially when hot streams operate near saturation temperature.

Key considerations

• Near-saturation service. Feedwater, blowdown, and hot process streams can operate close to the fluid’s vapor pressure, so even moderate pressure drops may drive local pressure low enough for vapor to form and collapse downstream.
• Long run times. Cavitation damage is progressive. A restriction that cavitates between outages is often discovered at the next shutdown, after the wear has accumulated.
• Vibration transmission. Cavitation-related vibration can travel along long mill piping runs, loosening supports and fatiguing small-bore connections away from the source.
• Practical evaluation. Actual system data — pressures, temperature, flow, fluid properties, and piping layout — is required to determine whether cavitation risk is present.

Managing pressure reduction and energy dissipation can help reduce cavitation-related vibration, noise, and downstream wear.