Before starting operation, fill the shell of the constant flow pump with the liquid to be transported, so as to start safely. If the ambient temperature is lower than freezing point, hot steam should be injected into the pump in advance for preheating treatment, and then the constant flow pump can be started. The rotation direction of the constant flow pump should be consistent with the oil inlet and outlet. Constant flow pump if the first operation, or after a long period of idle use, it is best in no-load or small load first run in an hour or so. If abnormal temperature rise, leakage, vibration and noise are detected in advance in the running in stage, stop the machine for inspection. The support or flange of the constant flow pump and its driving motor shall be installed on the same foundation. The foundation, flange or support shall have enough rigidity to reduce the vibration and noise generated during the operation of the constant flow pump. The motor and constant current pump shall be connected by elastic coupling, the coaxiality shall be less than 0.1 mm, and the inclination angle shall not be more than 1 degree. When installing the coupling, it is not allowed to knock with a hammer, so as not to damage the gear and other parts of the constant flow pump. If driven by pulley, sprocket, etc., bracket support should be set to prevent the driving gear bearing from radial force. When fastening the foundation screw of constant current pump and motor, the stress of the screw shall be uniform and the connection shall be reliable. When rotating the coupling by hand, you should feel that the constant flow pump can rotate easily without clamping and other abnormal phenomena, and then you can pipe. The inner diameter of oil suction pipe of constant flow pump should be large enough, and narrow passage or sharp turning should be avoided, elbow should be reduced, unnecessary valves and accessories should be removed, the installation height of pump should be reduced as far as possible, and the length of oil suction pipe should be shortened to reduce pressure loss.