The long time shutoff of hydraulic machinery can easily damage the system components due to corrosion, lack of lubrication, contamination, and more. If the system is not maintained properly during the shutdown period, the consequences will be severe and it can even make the system fail. Also, while restarting the system, the operator or service technician is required to follow certain checks. In this article, we can discuss such checks that need to be performed on hydraulic pumps while restarting after a long shutoff.
Hydraulic pumps are the most important component of every hydraulic machinery with the role of pressurizing hydraulic oil. It is advised to perform basic maintenance on hydraulic systems in regular intervals to ensure long service life and smooth working. Also, the checks that need to be done prior to restarting are as follows.
Check if the pump spins freely: Keeping the pump in an idle position for a long time will make it difficult for the positive displacement and centrifugal pumps to spin freely. The procedure to spin the pump includes a lockout of the prime mover, removing the coupling guard and then turning the shaft. The rust, contamination, or any other mechanical issue will not allow the pump to spin freely or make noises while turning. In such conditions, don’t force the pump to move, instead inspect it by removing from the machinery. Only use a strap wrench to turn a positive displacement pump or other pumps that can’t be spinned manually. Using a torque wrench will cause more damage to the pump.
Check coupling & Mechanical Seal condition: The coupling used for pump installation will provide smooth and hassle-free functioning and rotation of the pump shaft. It is required to check the condition of coupling for evidence of wear. Any foreign particle present in the coupling will be proof of misalignment. In such conditions, check pump alignment before restarting.
The mechanical seal in the hydraulic system will prevent hydraulic fluid leakage. Also, checking these seals before restarting will help to detect system leakage and related injuries.
Check oil and lubrication levels: Hydraulic oil quality and quantity are significant for machine operation. Contaminants in hydraulic oil can damage the system components easily when the oil is not tested prior to restarting. To detect contaminants in the oil, a sample is taken for testing and oil properties are monitored. Also, all moving components in the system need to be lubricated properly for safe and error-free working.
Check Hoses, Clamps and Connections: Properly inspect hoses, clamps and connections to check if they are tightened properly. If not, this will create leakages and related issues. So, if loose connections are found, tighten it properly.
Check Valves and Filters: Filters will help to prevent contamination. Before restarting, check important filters like suction, pressure, and return filter, and replace the dirty/damaged filters. Also, check if the valves are arranged in the correct position for the startup.
Prime and Vent the Pump: Make sure that the pump is primed and vented. Also, check the mounting bolt to ensure that the pump is secured safely.
Start-Up and Final Check: If all the above-mentioned checks are done properly, then turn on the system. If any issues are found, then rectify them.