What are the possible causes of insufficient flow of Dalian Chemical Pump

Dalian chemical pump is an indispensable key equipment in the chemical production process, and its insufficient flow rate will directly affect production efficiency, product quality, and even safety production. When there is insufficient traffic, it is necessary to systematically investigate various possible causes. The following are common problems that cause insufficient flow in chemical pumps and their solutions.

1、 Internal issues with the pump body

Impeller wear or damage

The impeller is the core component of a pump, and long-term operation can lead to impeller wear, especially when conveying media containing solid particles. The clearance between the worn impeller and the pump casing increases, reducing the volumetric efficiency of the pump. The solution includes replacing the impeller or repairing the worn impeller, and if necessary, considering using more wear-resistant materials.

Wear of mouth ring

Wear of the mouth ring (also known as the sealing ring) can lead to increased leakage inside the pump, causing the liquid in the high-pressure area to flow back to the low-pressure area, reducing the effective flow rate. When the clearance between the mouth rings exceeds 2-3 times the design value, they should be replaced in a timely manner. In corrosive media, mouth rings made of corrosion-resistant materials should be selected.

Corrosion or scaling on the inner wall of the pump casing

Chemical media are often corrosive, and long-term use can cause the inner wall of the pump casing to corrode and become rough, increasing flow resistance. Some media may also scale inside the pump, reducing the cross-sectional area of the flow channel. Regularly clean the pump body, and in case of severe corrosion, replace the pump casing or use anti-corrosion lining.

Mechanical seal leakage

Although external leakage is easy to detect, internal leakage of mechanical seals (leakage from the high-pressure side to the low-pressure side) is difficult to detect and directly affects flow rate. Check the wear of the sealing surface and replace the mechanical seal components if necessary.

2、 Inhalation system issues

Blockage of suction pipeline

Blockage of the filter on the suction line, incomplete opening of the valve, or foreign objects in the line can all limit the amount of liquid entering. The filter should be checked and cleaned, the valve opening should be confirmed, and if necessary, the pipeline should be disassembled for inspection.

Inhalation height too high

When the actual installation height exceeds the allowable suction height of the pump, it will cause cavitation and a decrease in flow rate. Re calculate the installation height and, if necessary, lower the installation position of the pump or switch to a suction pump.

Air leakage in the suction pipeline

Any air leakage in any part of the suction pipeline will damage the vacuum degree, resulting in insufficient flow. Use soapy water to check the connections of flanges, valves, etc., paying special attention to hidden leakage points below the liquid level.

Changes in medium viscosity

When the viscosity increases due to a decrease in temperature or a change in the composition of the medium, the flow resistance increases and the flow rate naturally decreases. The temperature of the medium should be maintained within the design range, and if necessary, the medium should be heated or a pump type suitable for high viscosity should be replaced.

3、 Eliminate system issues

Excessive resistance in the discharge pipeline

Long pipelines, small pipe diameters, too many bends, or insufficient valve openings can all increase system resistance. The pipeline design should be optimized by appropriately increasing the pipe diameter, reducing unnecessary pipe fittings, and fully opening the regulating valve to check the basic flow rate.

Export valve malfunction

Malfunctions such as valve core detachment and stem breakage may cause the valve to fail to fully open, making it difficult to detect on the outside. The actual opening of the valve should be checked for consistency with the indication, and if necessary, disassembled for inspection.

System back pressure increases

Downstream equipment blockage or increased operating pressure will increase system back pressure. Check if downstream filters, heat exchangers, and other equipment are unobstructed, and confirm if the system pressure is within the design range of the pump.

4、 Operating condition issues

Insufficient rotational speed

Motor faults, belt slippage, and incorrect frequency converter settings can all cause the pump speed to be lower than the rated value. Check the motor current and voltage, measure the actual speed, and adjust it to the design value.

Media vaporization

Low suction pressure or high medium temperature can cause cavitation in the pump, forming bubbles that hinder flow. It can be improved by reducing the temperature of the medium, increasing the suction pressure, or reducing the rotational speed.

The medium contains gas

Dissolved gases that precipitate or suck in air inside the pump will occupy the flow channel space. An exhaust device should be installed in the suction tank, and the sealing of the suction pipeline should be checked. If necessary, exhaust operations should be carried out.

Improper parallel operation

When multiple pumps are connected in parallel, significant differences in characteristics or improper operation may result in insufficient flow of one pump. The operating status of each pump should be checked and adjusted to the equilibrium working point.

5、 Selection and design issues

Improper selection of pump type

Centrifugal pumps, positive displacement pumps, and other types are suitable for different working conditions, and incorrect selection can lead to insufficient flow. Process parameters should be recalculated, and if necessary, a more suitable pump type should be replaced.

Parameter calculation deviation

The design flow rate does not match the actual demand, or the system resistance calculation is too low, resulting in insufficient pump head. Hydraulic calculations need to be redone to confirm whether the performance curve of the pump meets the requirements.

Material not suitable

Exceeding the expected corrosion rate of the material can lead to rapid deterioration of the flow channel. Actual medium conditions should be evaluated and more corrosion-resistant materials should be replaced.

6、 Solutions and preventive measures

Establish a system checklist

Develop a detailed inspection process, gradually investigating from simple to complex: first check obvious factors such as valve opening and speed, and then gradually delve into the interior of the pump body.

Strengthen operational monitoring

Install flow meters, pressure gauges, and other instruments, regularly record operating data to facilitate timely detection of abnormal trends.

Improve maintenance plan

Develop a reasonable maintenance cycle based on the characteristics of the medium, including regular disassembly and inspection, replacement of vulnerable parts, and other preventive maintenance.

Operator training

Improve operators' understanding of pump performance, identify early abnormal phenomena, and avoid improper operation.

Quality Management of Spare Parts

Using original or reliable spare parts, inferior spare parts may solve the problem in the short term but may bring long-term hidden dangers.

The reasons for insufficient flow of chemical pumps are complex and often involve multiple factors working together. Technicians need to analyze specific phenomena systematically in order to accurately identify the root cause and take effective measures. Prevention is better than cure, and good daily maintenance and management can greatly reduce the probability of insufficient flow and ensure the stable operation of chemical production.