1. Preparation
Check the environment and equipment status: Ensure that the working environment is dry, ventilated and free of flammable and explosive items; Check that the power cord, hose, valve and other accessories are intact, and the lubricating oil level meets the requirements (the mechanical pump needs the oil level to reach 2/3 height).
System sealing test: After closing all valves, start the vacuum pump, observe whether the vacuum degree is stable, and confirm that there is no leakage.
Manual pre-inspection under special circumstances: If the pump has not been used for a long time or the ambient temperature is too low, it is necessary to manually rotate the pump shaft to confirm that there is no jamming, and heat the pump oil to above 15°C if necessary.
2. Startup process
Connection and valve adjustment: Seal the pump inlet with the pumped system, ensure that the inlet valve is closed, and the outlet valve is open (the water ring pump needs to close the inlet valve first and supply water to the specified amount).
Step-by-step start:
First turn on the power, start the front pump (such as a mechanical pump), and observe the operating status (noise, vibration, etc.). After the fore-stage pump is stable, start the main pump (such as Roots pump) and gradually open the air inlet valve to adjust the pumping speed.
The water ring pump needs to adjust the water supply to the technical specifications after the motor turns correctly.
III. Operation monitoring
Observe key indicators: pay attention to vacuum, oil temperature (bearing temperature does not exceed 60°C), cooling water flow, etc. If abnormal noise or oil injection occurs, the machine needs to be stopped for inspection.
Handling condensable gases: When extracting such gases, the gas ballast valve needs to be opened to prevent condensation and contamination of the pump oil.
IV. Shutdown operation
Sequential shutdown: First close the system air inlet valve and gradually reduce the pumping speed (to avoid backlash).
Stop the main pump and then the fore-stage pump, and finally cut off the power supply.
The water ring pump needs to stop the water supply first and then turn off the motor. If it is not used for a long time, the liquid in the pump needs to be emptied to prevent freezing and cracking.
Anti-oil backflow measures: When the pump is stopped, the pressure differential vent valve or gas ballast valve is used to open the pump to the atmosphere.
V. Maintenance points
Regular maintenance: Replace lubricating oil (3-4 times a year for mechanical pumps), clean bearings, and check seals (stuffing or mechanical seals).
Cleaning and corrosion prevention: Clean impurities in the pump body and pipelines, and store them dry if they are not used for a long time.
Safety precautions:
Wear protective equipment during operation, and it is forbidden to extract flammable, toxic or corrosive gases.
In case of abnormal conditions (smell, overheating, etc.), stop the machine immediately for investigation.
