Common faults of metering pumps-Hezhong Environment (Beijing) Co., Ltd. was established in 2003

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Common faults of metering pumps

Published Time:

2022-11-18

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1) The metering pump is not sucking liquid normally

Rotate to 100% stroke length. This aligns the backplate leak drain hole with the bottom of the pump. Adjust the hydraulic end and diaphragm to the appropriate position during pump operation.

The pulse duration may not be long enough for the reaction time. Relative to the standard pulse width of 80msec, the flow monitor pulse width extension can be activated, increasing the pulse width to 300msec. Activate the intelligent conversion switch, remove the cover of the fixed circuit board, and remove the jumper X-1. This activates the extended function, allowing more time before the fault

indication.

The metering pump is installed with a self-priming pump head and uses a self-priming suction method. Keep the suction line as short as possible.

2) Replacing the metering pump diaphragm

Removing the old diaphragm is often troublesome. Here are some additional suggestions on how to remove the old diaphragm.

1. After loosening the pump head, adjust the stroke length to 10% before removing the pump head. This ensures sufficient pressure on the electromagnetic shaft to maintain a secure connection, allowing the diaphragm to be unscrewed.

2. Pull out the hydraulic end to disengage the screws from the holes. Grab the liquid end and rotate counterclockwise. With slight resistance, the diaphragm can be unscrewed.

3. The metered chemicals may crystallize in the hydraulic end, causing the check valve ball and seat to malfunction.

4. There may be gas leakage at the suction end of the metering pump. The O-ring may be missing or the suction valve connection may be loose on the hydraulic end suction side.

3) When metering a high-viscosity medium using a flow monitor, a flow fault indication signal is received during priming. How can this problem be solved?

By loosening the four pump head screws, move the hydraulic end. Rotate the stroke length to 10% and grab the hydraulic end, then slide it out of the screw holes so that the screws do not contact them, but still hold the backplate and diaphragm. Then rotate this component counterclockwise. With slight resistance, the diaphragm will loosen from the electromagnetic shaft. If the diaphragm has not yet loosened, apply some lubricant to the

contact surface between the diaphragm and the electromagnetic shaft. After a few minutes, gently tap the diaphragm with a small plastic hammer. Then repeat the above steps.

4) How to prevent the metering pump stroke positioning motor from burning out?

1. Remove the four screws securing the pump head. The screw locations are on the back of the metering pump.

2. Check if the drain pipe is installed and the drain valve is closed? The drain valve needs to be open during the metering pump priming stage. Note: Not all metering pumps have a drain valve.

3. After the diaphragm is installed and the backplate leak drain hole is in a vertical position, install the pump head. Ensure that the suction valve is aligned with the leak drain hole and the screws on the hydraulic end are aligned with the corresponding four holes.

5) Hydraulic metering pump flow rate is reduced or inaccurate?

1. Open the bleed valve on the three-way valve.

2. Replenish oil sufficiently through the oil replenishment valve.