Elimination of Common Faults of Solenoid Diaphragm Metering Pump

When the solenoid diaphragm metering pump has been running for a period of time and needs to be stopped for maintenance, it must be considered that there may be liquid medicine under pressure in the outlet pipeline of the pump, Therefore, it is necessary to first rotate the exhaust knob on the side of the multi-function valve for 1/4 turn to make the liquid medicine left in the outlet pipeline flow back to the medicine barrel through the bypass hose, and then carry out the next maintenance operation. Otherwise, it may cause splashing and personal injury. In addition, the threaded connection of the upper and lower check valves adopts the end face seal. It is forbidden to wind the raw material belt for sealing. It is forbidden to use pipe tongs and other tools to screw in, so as to avoid fracture.

There is no sound when the metering pump is powered on

Check whether the power supply of the solenoid diaphragm metering pump is normal, such as whether there is voltage or excessive current. If it is a signal-controlled metering pump, please switch to the manual position to see if it runs normally: If the manual position works normally, please check whether the control signal is normal.

Check the original power supply or replace it with a normal power supply and confirm that it is in the manual position. If it still does not work after doing so, please contact the supplier.

After the metering pump is energized, there is a running sound, but no liquid medicine

1. Check whether the liquid level of the medicine barrel is normal, and whether the bottom valve is blocked or floated.

2. Check whether the inlet and outlet pipelines are completely exhausted.

Rotate the exhaust valve until the liquid is discharged from the bypass hose. If the liquid is not discharged for a few minutes, you can manually fill the pump with water or liquid, and then run the pump;

3. Check whether the components in the one-way valve are reversed or missing (this situation is likely to happen after the metering pump has been disassembled and washed);

There are spherical check valves at the inlet and outlet of the pump, and the valve ball and valve seat are separate. The one-way valve only allows the positive flow of liquid medicine, and if it is in the reverse direction, it will form a seal. If one of them is lost, or any of them is installed in the opposite direction, the metering pump will not work normally.

Metering pump flow is low, flow instability or pressure does not reach the rated value

1. Check whether the check valve, especially the inlet and bottom valve of the pump are blocked, and flush with clean water;

2. Check whether the accumulated operation time is more than 5000 hours. If it is more than 5000 hours, it is necessary to purchase spare parts package and replace vulnerable parts， such as check valve.

There is liquid medicine flowing out from the gap between the hydraulic section end and the driving end of the metering pump

This situation shows that the diaphragm has broken and the pump must be stopped immediately. If it is corrosive liquid, the pump should be cleaned immediately. At the same time, contact the supplier to purchase diaphragm or spare parts package for replacement.

The actual flow of the metering pump is inconsistent with the rated flow on the nameplate

Solenoid diaphragm metering pump belongs to reciprocating positive displacement pump. The actual flow rate is related to factors such as inlet pressure, outlet pressure, specific gravity of the medium, viscosity, and whether the voltage is stable.

The flow rate on the nameplate of the NEWDOSE solenoid diaphragm metering pump is measured when the inlet is at normal pressure, the outlet is at the nameplate pressure, and the medium is pure water. In actual use, due to the change of conditions, it is normal that the measured flow rate is inconsistent with the nameplate flow rate. Therefore, for the occasions with higher requirements, after the installation is completed, it is necessary to calibrate at the inlet according to the actual operating conditions (same medium, same outlet pressure), and record the calibration results. At the same time, the metering pump is set according to the calibration result during the formal operation.