1.Clogging or air leakage in the suction pipeline
Accumulation of impurities and sediments in the suction pipeline will hinder the normal suction of the medium; loose seals or cracks at pipeline joints will cause air to seep into the pump body, damage the suction-discharge balance of the pump, and then lead to flow fluctuation or reduction.
2.Severe wear of screw pump stator and rotor
The stator and rotor are the core flow components of the progressive cavity pump. The matching clearance between them becomes larger due to long-term operation, medium scouring or solid particles contained, the sealing performance of the pump body decreases, medium back flow occurs, which directly causes the flow rate to decrease and become unstable.
3.Blockage of the inlet filter screen
The inlet filter screen is used to intercept large particle impurities in the medium. If it is not cleaned in time, the filter pores will be blocked, the medium suction volume will drop sharply, and the actual output flow of the pump will decrease accordingly.
4.Medium viscosity exceeding the applicable range
Progressive cavity pumps have clear requirements for the viscosity of the conveyed medium. Excessively high viscosity will increase the medium flow resistance and reduce the pump’s suction capacity; excessively low viscosity is prone to leakage. Both situations will lead to unstable or reduced flow rate.
5.Abnormal rotation speed (too low or fluctuating)
The flow rate of the progressive cavity pump is positively correlated with the rotation speed. Too low motor speed will directly reduce the pump’s output flow rate; speed fluctuation will cause the flow rate to vary, and common causes include faults of the speed control device and unstable power supply voltage.
6.Wear or jamming of the universal joint assembly
The universal joint assembly is responsible for power transmission. If the components are worn, deformed or jammed by impurities, the power transmission will be intermittent or unstable, resulting in unsmooth operation of the rotor and then flow fluctuation.
7.Outlet valve not fully opened
If the outlet valve is not fully opened, it will artificially increase the pump’s outlet resistance, the pressure inside the pump will rise, the medium discharge will be blocked, the actual output flow rate will be less than the rated flow rate, and flow fluctuation may occur due to resistance changes.
8.Air binding phenomenon inside the pump
If the pump is not filled with medium before startup, or a large amount of air enters the pump body during operation, the pump will not be able to suck and discharge the medium effectively, resulting in idling or a sharp drop in output flow rate. This phenomenon is called air binding, which is common in self-priming progressive cavity pumps.
If you have any after-sales issues, please contact us.
e-mail:celia@kynspump.com,WhatsApp:+86 153 1226 1613,WeChat:pump1668,
NEMO/Netzsch/seepex/Mono progressive cavity pump spare parts，such as stators, rotors, coupling rod, driving shaft, seals
