Ensuring the longevity and reliability of high-temperature molten salt pumps requires strict adherence to specific operational and maintenance protocols. Due to the extreme temperatures and the nature of the media, neglect can lead to catastrophic failure.
Installation and Pre-Startup Checks
Proper installation is critical. The pump's discharge flange must never be subjected to external pipe loads, as this can misalign the shaft and cause excessive vibration. Prior to startup, the molten salt must be fully melted, and the rotor should be turned manually to ensure it moves freely . A crucial step is activating the cooling water system for the bearing housings; this cooling must remain operational whenever the tank contains high-temperature salt, regardless of whether the pump is running.
Operational Monitoring
During operation, operators must vigilantly monitor several parameters. This includes checking for abnormal vibration or noise, which can indicate bearing wear or imbalance. The pump current is a key diagnostic tool; a sudden drop may indicate cavitation or "pump empty" operation, while a spike suggests mechanical binding . For pumps with packed glands, specific attention is required. High-temperature molten salt pumps often use nitrogen-lubricated metal packing rings. This nitrogen flow must be monitored, and importantly, the packing should never be adjusted while the pump is in operation.
Routine Maintenance
Lubrication management is vital. Bearings should be greased regularly, with a full oil change recommended annually or every 1,500 operating hours. Daily inspections should verify that cooling water lines are clear and that all flange bolts remain tight . Finally, if a pump trips or shows instability, it should be stopped immediately to inspect for salt solidification in critical clearances, which can occur if heat trace or circulation fails .
