Common faults of a three screw pump include vibration and noise, decreased flow rate, self-priming issues, and oil damage. Specifically, as follows: 12
Vibration and noise: This may be due to poor sealing between the pump body and the end cover, resulting in air intake, or the pump and motor being installed out of center. The solution includes improving the flatness of the pump body and end cap, adjusting the relative position between the pump and motor, or replacing the oil seal with a new one. 14
Flow decrease: It may be caused by air leakage or blockage in the suction pipeline, suction height exceeding the self-priming capacity of the pump, safety valve leakage, or significant mechanical wear. The solutions include eliminating air leaks and blockages, reducing suction height, repairing and replacing sealing components, or replacing vulnerable parts. 24
Self suction problem: This is usually related to air leakage or inadequate sealing of the inlet pipeline, or pipeline resistance exceeding the pump's self-priming capacity. The solution includes checking and repairing the air leakage problem, reducing pipeline resistance. 3
Oil shortage damage: Long term oil shortage operation may cause jamming or shaft jamming, especially when oil is not injected during the first start-up. The solution includes ensuring that there is sufficient oil inside the unit during the first start-up and regularly checking the oil seal condition. 56
These faults not only affect the performance of the pump, but may also shorten its service life, so regular inspection and maintenance are very important.
