Small issues that should be noted in the operation of multistage pumps(1)

Vertical multistage pumps are vertical, single suction, multistage, sectional centrifugal pumps suitable for urban water supply and central heating systems. It is used to transport clear water or liquids with physical and chemical properties similar to clear water. The temperature of the pump conveying medium is below 80℃, and the temperature of the DLR type pump conveying medium is below 150℃.

Product characteristics of multi-stage pump

1, the pump is vertical structure, with the characteristics of small footprint, the centre of gravity of the pump coincides with the centre of the pump foot, thus smooth operation, small vibration, long life.

2, The pumps are of the same calibre and on the same horizontal centre line, so there is no need to change the structure of the pipeline and they can be installed directly in any part of the pipeline, making installation extremely convenient.

3, the motor plus rain cover can be directly placed outside the use, without the need to build a pump room, greatly saving infrastructure investment.

4, The pump head can be changed by changing the number of pump stages (the number of impellers) to meet different requirements, so the scope of application is wide.

5, Shaft seal adopts hard alloy mechanical seal, reliable seal, no leakage, small mechanical loss.

6, High efficiency and energy saving, beautiful appearance.

7, Note 50 caliber or more internal parts casting forming.

Multi-stage pump fault and solution

Pump stuffing box leakage is too large

1) Shaft bending

Elimination measures: straighten the shaft or replace it as required.

2) Coupling or pump and drive device are not aligned

Elimination measures: Check the alignment and re-align if required.

3) Incorrect bearing lubrication or bearing wear

Elimination measures: Check and replace as required

Bearing temperature too high

1) Shaft bending

Elimination measures: Straighten the shaft or replace as required.

2) Misalignment of coupling or pump and drive unit

Elimination measures: Check alignment and if required, re-align.

3) Incorrect bearing lubrication or bearing wear

Elimination measures: Check and replace as required.

4) Stress in the pipe on the pump casing is too large

Elimination measures: Remove the stress and consult with the manufacturer's representative. After the stress has been removed, check the alignment.

5) Too much lubricant

Elimination measures: Remove the plug so that the excess grease is automatically discharged. If the pump is oil lubricated, drain the oil to the correct oil level.

Overheating of the stuffing box

1) Packing or seal in the stuffing box is worn, allowing air to leak into the pump casing

Elimination measures: Check the packing or seal and replace as required. Check that lubrication is normal.

2) Stuffing box not correctly packed (insufficient packing, not correctly stuffed or run together, packing too tight)

Elimination measures: Check the packing and refill the packing box.

3) Packing or mechanical seal has design problems

Eliminate measures: consult the manufacturer.

4) Mechanical seal damage

Elimination measures: Check and replace as required. Ask the manufacturer for advice.

5) Shaft sleeve scratching

Elimination measures: Repair, re-machining or replacement as required.

6) Packing is too tight or mechanical seal is not properly adjusted

Elimination measures: Check and adjust packing and replace as required. Adjust the mechanical seal (refer to the manufacturer's instructions supplied with the pump or ask the manufacturer for advice).