Three screw pump is designed and manufactured according to the national standard GB10887-89. Three-screw pump is a rotor-type positive displacement pump, mainly using the principle of screw engagement, relying on rotating screw in the pump sleeve intermeshing, the medium is closed in the meshing chamber, along the screw axial continuous push to Outlets provide a steady pressure on the system. Widely used in petroleum, electricity, chemical fiber, shipbuilding, metallurgy, glass, machinery, machine tools, highways and other industries. 1. Startup (1) Before starting the inspection of all pipe flanges, joints tightness, tight leak. (2) Turn the coupling to check whether the rotation of the pump is flexible. If there are other problems such as jamming, remove the pump. (3) The first start should unscrew the safety valve refueling screw plug or remove the cover, injecting liquid into the pump and hand counterclockwise rotation of the coupling to ensure that the friction pairs have sufficient lubrication. (4) Before starting, all the valves in the suction and discharge lines should be opened completely, and it is forbidden to start the valve. Check motor rotation is correct. (5) After the preparation is completed, can be connected to the power, direct start. 2. MAINTENANCE (1) If the sound of the pump and the motor is abnormal (or the current meter pointer rises rapidly), stop immediately to find out the cause. (2) The outlet pressure must not exceed the pressure shown on the pump's nameplate. (3) Safety valve has been adjusted before production, can not be arbitrarily mobilized. (4) If the pipeline system fails, there should be a safe return to stop troubleshooting immediately. General safety valve reflux time shall not exceed three minutes. If the pump is too long, the pulse wave generated by the returning fluid constantly vibrates the pump and even kills the pump. (5) drip leakage at the shaft seal is a normal phenomenon, such as oil leakage greater than 10 ml / hour, should stop troubleshooting or replace the new seal components. (6) In the circuit controlling the operation of the motor, there should be overload protection components. If the pump bites, should cut off the power automatically, in order to prevent the electric motor burn out. 3. Stop screw pump must not close into the outlet valve shut down. If heavy fuel oil, asphalt and other highly viscous media are to be transported, the pump thermal insulation valves 1, 2 should be opened to keep the temperature of the pump after the standby pump is shut down. This will prevent the pump or motor from being damaged immediately when the emergency starts.