1、 Switching of tetrafluoro centrifugal pump When switching the pump, the principle of keeping the system flow and pressure unchanged shall be strictly guaranteed, and evacuation and volume grab are strictly prohibited. Switching under normal conditions: 1. The standby pump should be ready for all start-up work. 2. Open the suction valve of the standby pump (pump filling and exhaust), and start the standby pump according to the normal procedure. 3. Check the outlet pressure, current, vibration, leakage, temperature, etc. of the standby pump. If they are normal, gradually increase the opening of the discharge valve, and gradually reduce the opening of the discharge valve of the original operating pump, so as to maintain the system flow and pressure as much as possible. When the outlet pressure and flow of the standby pump are normal, close the discharge valve of the original running pump and cut off the power supply, and treat it as stopping the pump. Switching in case of emergency: The switching of centrifugal pump in emergency refers to accidents such as oil spray, motor fire, serious pump damage, etc. 4. The standby pump should be ready for all start-up work. 5. Cut off the power supply of the original running pump, stop the pump and start the standby pump. 6. Open the discharge valve of the standby pump to make the outlet flow and pressure reach the specified value. 7. Close the discharge valve and suction valve of the original running pump and deal with the accident. 2、 Preparation before startup of tetrafluoroethylene pump 1. Pump filling (except for the submerged pump, pump filling shall be carried out before the start of other pumps (the previous start of the self-priming pump) (that is, the pumped medium must be filled with the pump chamber)) 2. Pump filling of the backflow device: open the stop valve of the inlet pipeline, open all exhaust pipelines, discharge gas, slowly rotate the rotor, and close the exhaust valve when there is no bubble in the pumped medium. 3. Pump filling of suction device: open the stop valve of the inlet pipeline, open all exhaust pipelines, discharge gas, fill the pump (the suction pipe must be equipped with a bottom valve), slowly rotate the rotor, and close the exhaust valve when there is no bubble in the pumped medium. 4. Open all auxiliary systems, and require all auxiliary systems to work for at least 10 minutes. The next step can be carried out only after the whole auxiliary system works stably. Here, the auxiliary systems include lubricating oil system, seal flushing system, cooling and insulation system, etc; 5. Turn the equipment to check whether it rotates flexibly; Jog the motor and judge whether the rotation direction of the pump is correct again; Fix the coupling shield after confirmation. 6. (pump with dry gas sealing system) the dry gas sealing system is put into operation. Open the nitrogen inlet valve to pressurize the sealing chamber. The air supply pressure of dry gas seal must be between 0.5 ~ 1.0MPa. Each pump shall adjust the pressure and flow of the sealing chamber according to the specific requirements. 3、 Startup of tetrafluoroethylene pump 1. Confirm that the suction valve is fully open and the discharge valve is closed or slightly open; When there is a small flow pipeline, the discharge valve shall be fully closed and the small flow valve shall be fully opened. 2. Close the stop valve of the outlet pipeline (small flow must be guaranteed); 3. Start the motor to make the pump rotor reach the running speed; 4. Slowly open the outlet valve to make the outlet pressure and flow of the pump reach the specified value. When opening the outlet valve, check the motor current change to avoid motor overload. When the flow increases, attention should also be paid to whether the seal of the pump has abnormal leakage, whether the vibration of the pump is normal, whether the pump body and motor have abnormal sound, the change of outlet pressure, etc. if the pump has abnormal leakage, abnormal vibration, abnormal noise or the outlet pressure is lower than the design value, the cause should be found out and handled. 5. After the pump operates normally, check the outlet pressure, outlet flow, motor current, temperature of bearings and seals, oil level of lubricating oil, vibration and noise of the pump and leakage of seals; Close the valve of small flow bypass (according to the process needs). Keep relevant equipment operation records.