Seek assistance to shut down the backup screw pump
Thread Content
Our company’s compressor oil station is equipped with two screw pumps, labeled AB. During shutdowns, the standby pump started up due to an accidental interlock mechanism; however, when attempting to shut down that standby pump, it was found that the pressure in the lubricating oil main pipe could drop to the level that triggers an automatic shutdown. We would like to discuss with everyone how to shut down the standby pump safely! My personal idea is to gradually reduce the flow rate through the inlet valve of the standby pump, and to shut down the standby pump once its outlet pressure reaches a certain level. I wonder if anyone has any new, safer methods!
Of course, it is also possible to slightly increase the control oil pressure and the pressure in the lubricating oil main pipe while respecting the limits of the backup pump; this should be safer
Keep paying attention; I hope experts will continue to provide answers
After a year of working, let me share what comes to mind. I hope experts can tell me the correct answer so that everyone can learn and exchange ideas. There should be a pressure regulation mechanism between the pump outlet and the oil cooler, usually in the form of a control valve, with a gate valve serving as the bypass. When the standby pump starts at the same time, the pressure in the main pipe increases and the flow rate rises. If the control valve operates automatically, its opening degree gradually increases in order to maintain the set oil supply pressure. When the standby pump is stopped, the flow rate in the main pipe drops sharply, and if the control valve cannot adjust its opening degree quickly enough, the oil supply pressure may fall below the alarm or interlock values. However, as the control valve closes, the normal set oil pressure can be restored. Therefore, I recommend setting the control valve to manual mode, closing it to an appropriate degree, and increasing the oil supply pressure slightly