Duwan G40-2 Variable Frequency Drive Screw PumpCommon Fault Analysis：

Reasons for insufficient screw pump flow

1. The inlet flow of the screw pump is already relatively small.

Due to the low inlet flow into the pump, it cannot keep up with the discharge volume from the pump outlet.Therefore, the phenomenon of insufficient flow in screw pumps may occur, and the solution is to increase the flow rate at the inlet of the screw pump.

2. The inlet pipeline seal of the screw pump was not properly handled.

Pipe joints or the pipes themselves are not adequately sealed.If the seal is not up to par, it will result in insufficient pressure and a lack of flow. At this point, you should either replace the pipe with a new one or fix the leaking area.

3. Screw Pump Inlet and Outlet Filter Clogging

A clogged inlet pipe or filter is a significant reason for insufficient screw pump flow. Therefore, cleaning the blocked area is necessary to resolve the issue of insufficient screw pump flow.

4. The rubber sleeve of the screw pump due to idling or incompatibility with the liquid medium being conveyed

This situation often occurs due to a chemical reaction between the liquid medium being transported and the rubber sleeve of the screw pump., Damage to the rubber sleeve causes the gap between the rubber sleeve and the screw pump shaft to increase, resulting in insufficient flow of the screw pump. In such cases, it's advisable to replace the rubber sleeve with a more suitable one as soon as possible.

5. The motor speed of the screw pump products is reduced.

The reduced speed of the motor in screw pump products often leads to insufficient flow rate of the screw pump.For low rotational speeds, increasing the speed usually results in a higher flow rate. However, if transporting a highly viscous liquid medium, even increasing the speed may not suffice to achieve adequate flow from the screw pump. In such cases, it is recommended to consult the manufacturer of the pump for a solution.

6. Incorrect screw pump selection

Selection is quite important.Because the flow rate of commonly used screw pump products is calculated and tested based on the water level standard.If the specific gravity or viscosity of the fluid being conveyed is greater than water, it is also necessary to consider this when selecting the screw pump type; otherwise, it may lead to insufficient flow of the screw pump.Due to reasons such as excessive or insufficient head.

Duwan G40-2 Screw PumpMotor overheatingThe reason for:

Application Range (Flow, Head) Exceeds Screw Pump Design Requirements; Select Appropriate Motor According to Series Type Spectrum

The medium's specific gravity exceeds the motor rating of the screw pump, therefore, a suitable motor for the screw pump must be configured.

The filler cover is too tightly pressed down, or the mechanical seal spring is too tight. Please adjust the compression of the filler cover or mechanical seal spring again.

Poor pump assembly quality, with friction points or misalignment between the motor and pump shaft. At this point, you can inspect the assembly quality and eliminate assembly malfunctions.

Jiangsu Du'an Environmental ProtectionG TypeScrew PumpProduct Description:

Duwan Environmental ProtectionG-type screw pumpThe core part features an external thread.“A 'rotor' and an internal threaded 'stator,' when the rotor is inserted into the stator, an independent and continuous sealed space known as the 'sealing chamber' is formed in the gap. As the rotor rotates within the stator, it generates a powerful suction force capable of drawing in high-viscosity liquids, continuously producing new sealing chambers to move the liquid towards the discharge side. The liquid within the intake sealing chamber is continuously transported forward within the sealed space.”

The cross-sectional area of the sealed cavity is independent of the position of the rotor, remaining fixed at any instant. The discharge volume is also maintained constant, thus the discharge volume per unit time is directly proportional to the rotational speed of the rotor. Furthermore, simply by reversing the direction of the rotor's rotation, the direction of intake and discharge can be reversed.

Screw pumpAdvantages:

Wide application range, capable of conveying all types of flowing and even non-flowing materialsAvailableContinuous low pulsation transmission medium is not agitated during pumping, unaffected by compression and shearing. The flow rate is proportional to the speed, allowing variable frequency adjustment of the flow rate, with high precision metering and high efficiency.，All liquids can be pumped with minimal agitation and pulsation.，Easy to maintain and service。

Duwan Environmental ProtectionType G screw pumpTraffic can reach up to 400 m³/h output pressure up to 7.2 Mpa

Current-carrying metal components can be made from various materials, ranging from tool steel to nickel./Chrome steel, high corrosion-resistant materials such as duplex stainless steel, Hastelloy, and titanium alloys, etc.Regular materials are categorized as:304 stainless steel, 316 stainless steel. The motors are categorized into AC speed regulation, electromagnetic speed regulation, variable frequency speed regulation, standard motors, and explosion-proof motors, etc.

Screw Pump Sealing DeviceUtilizing various stator rubber materials, from wear-resistant natural rubber(NBR),三元乙丙橡胶(EPDM),氯磺化橡胶(CSM),四氟(PTFE),氟橡胶(FPM), and hydrogenated nitrile rubber (HNBR)

Filling seal or mechanical seal; other sealing options are also available.

Duwan Environmental ProtectionG-Type Screw PumpStrict quality standards and testing proceduresGuaranteed to be intact and superior in performance before shipment.

Screw pumps are positive displacement rotor pumpsIt operates by吸入 and 排出液体 through the volume changes of the sealed cavity formed by a screw and sleeve. Screw pumps are categorized by the number of screws into single, double, triple, and five-screw pumps. The features of screw pumps include steady flow, low pressure pulsation, self-priming capability, low noise, high efficiency, long service life, and reliable operation; their outstanding advantage lies in the ability to convey media without creating vortices and being insensitive to the viscosity of the medium, making them suitable for transporting high-viscosity media.

Du'an Environmental ProtectionG TypeScrew pump manufacturing, inspection, testing, and acceptance：

Duwan Environmental Protection for screw pumpsEstablish a comprehensive quality inspection system to ensure that all factors affecting the product's safety, reliability, operational performance, and long-term operational performance have been considered, and necessary tests, inspections, and calibrations are conducted on processing, inspection, and testing equipment.

Sludge screw pump manufacturing, inspection, testing, and acceptance should be conducted in accordance with relevant standards, specifications, and regulations. The seller should note that these requirements do not replace the internal quality assurance measures of the manufacturing plant. The seller shall submit the required inspection, testing results, and records.UserAcknowledged.