Stable material discharge of a pump relies on four core prerequisites:smooth suction conditions,standard rotor meshing status,unobstructed conveying pipelines,and adequate power output.Abnormalities in any of these links will trigger flow related failures.Specific troubleshooting and resolution measures are presented below.

- Bonve Pump Industry Cam Type Twin Rotor Pump -

1.Suction Port Blockage or Suction Cavitation(Accounting for Approximately 40 %of Failures)

Typical symptoms include idling of the pump body,fluctuating flow rates,dull humming noise,and distinct negative pressure suction sound at the suction port.These are the most characteristic signs of suction port malfunctions.

Operating procedures:Power off and shut down the unit first.Dismantle and inspect the suction port filter screen and pipeline,and clear accumulated impurities such as particles,agglomerates and fibers.Replace damaged filter screens in a timely manner;the recommended filter screen aperture shall be within 0.3 mm.Meanwhile check the liquid level of the suction tank to ensure the liquid level submerges the suction port.The suction lift should preferably not exceed 3 m,otherwise the suction capacity will drop significantly.Apply soapy water to suction pipe joints and flanges and observe for air bubbles.Bubbles indicate air leakage;retighten connections or replace gaskets accordingly.

2.Pump Cavity Air Binding(Accounting for Approximately 15 %of Failures)

The pump runs yet no material flows out,or the flow rate is extremely low,accompanied by crackling sounds inside the pump cavity—these are typical manifestations of air binding.Air occupies the pump cavity volume so rotors cannot draw in media effectively.

Solutions:Shut down the pump and open the vent valve on top of the pump body to slowly evacuate trapped air.Close the vent valve only after continuous bubble free material overflows.For media prone to foaming,install a degassing device at the suction inlet,or reduce rotational speed to 300 500 r/min to suppress bubble generation.When excessive medium temperature causes vaporization,implement cooling or install cooling devices to eliminate air binding risks.

3.Mismatch Between Rotational Speed and Medium Viscosity(Accounting for 10 %of Failures)

Insufficient flow occurs when conveying high viscosity media;the pump bears heavy loads and the motor housing overheats.This points to improper speed settings.

Cross reference medium viscosity against nameplate parameters of the pump.If viscosity exceeds 1000 cp,appropriately lower the rotational speed to 300 500 r/min to avoid flow loss caused by rotors forcing through viscous material.For units fitted with variable frequency motors,adjust speed gradually via the frequency converter to reach the balance point for qualified flow.Rotational speed is directly proportional to flow rate:excessive speed triggers splashing and cavitation,while insufficient speed fails to meet flow requirements.Pre heating high viscosity media to a suitable temperature can effectively cut flow resistance and improve conveying efficiency.

4.Excessive Rotor Clearance or Rotor Wear(Accounting for 15 %of Failures)

The pump appears to operate normally,yet flow keeps declining with faint metallic friction noise.This usually signals abnormal rotor clearance.

Shut down the pump and remove the pump end cover to inspect rotor meshing clearance.The normal clearance range shall be 0.1 0.3 mm.If clearance exceeds 0.5 mm or unilateral wear occurs,media will flow back through gaps and bring about flow loss.Minor wear may be repaired by original manufacturer precision grinding to restore standard clearance.For severe wear such as edge chipping or cracks,replace rotors in pairs of identical models;never mix old and new rotors which would result in poor meshing.Remove scale and adhered deposits on rotor surfaces before reassembly.

5.Outlet Pipeline Blockage or Pressure Build up(Accounting for 8 %of Failures)

Material is discharged but flow is very low;outlet pressure rises abnormally above 1.2 times the design pressure,and pipelines vibrate violently.These are typical signals of pipeline obstruction or pressure build up.

Inspect valves and elbows on outlet pipelines and remove material agglomerates and sediments.Adjust the opening of outlet valves appropriately and keep outlet pressure within±0.1 MPa of the design value to prevent flow attenuation induced by back pressure.Excessively long pipelines or numerous elbows increase turbulent resistance.Install fixing supports;shorten pipeline sections or enlarge pipe diameters when necessary.

6.Seal Leakage(Accounting for 5 %of Failures)

Discharge remains acceptable but flow decreases gradually;medium seepage appears at the pump shaft or end cover and seal face temperature rises,meaning seals have failed.

Dismantle and examine the mechanical seal.Check for scratches on sealing faces,ageing or damage of O rings,and spring failure.Fit genuine OEM seal components and fasten them at a torque of 25-30 N·m to guarantee tight sealing face contact.Fill the seal chamber with proper amount of grease to prevent accelerated damage from dry friction.

7.Motor or Coupling Malfunction(Accounting for 5 %of Failures)

Abnormal motor operation including overheating,abnormal noise and insufficient rotational speed will inevitably lead to substandard pump output flow.

Check motor voltage and current.Voltage fluctuation shall be controlled within±5 %and current shall not exceed rated values.Verify key details:ageing or damage of coupling elastic cushions,and whether shaft misalignment between pump shaft and motor shaft surpasses 0.05 mm.Realign shafts if misalignment is excessive;repair or replace defective motors.

8.Mismatch Between Pump Model and Conveyed Medium(Accounting for 2 %of Failures)

After inspecting all components,flow still fails to meet requirements and the pump frequently overloads.The root cause may lie in improper model selection at the initial stage.

Recheck medium properties and pump specifications.When media feature overly high viscosity or large particles,select alternative models with larger displacement and superior wear resistance.If actual required flow surpasses the pump’s design flow capacity,switch to a pump matching process flow demand and avoid overloading the unit beyond its capacity.For particle laden or crystallizable media,adopt rotors made of rubber lined material or 316L stainless steel to mitigate wear and blockage from the source.

Bonve pump always adheres to the philosophy of "Wholeheartedly Making Good Rotor Pumps," committed to providing global customers with customized conveying and mixing solutions. If you have technical inquiries, selection needs, case references, or other cooperation intentions related to Bonve rotor pumps, please feel free to contact us.  

Service Hotline: 0574-87588986 13586591794  

Official Website: www.bvpumps.com  

Business Email: market@bonvepumps.com  

We look forward to working with you to drive efficiency and innovation in industrial fluid transmission with precision technology.