Introduction to the ZX Self-Priming Pump (Self-Priming Clear Water Centrifugal Pump)

The ZX series self-priming centrifugal pumps are self-priming pumps that feature a compact design, convenient operation and maintenance, stable performance, easy servicing, high efficiency, long service life, and strong self-priming capability. They eliminate the need for foot valves in the piping system; prior to start-up, it suffices to fill the pump casing with a measured amount of liquid, thereby simplifying the piping arrangement and improving working conditions. Materials: cast iron, stainless steel.

Application Scope of ZX-Type Self-Priming Pump (Self-Priming Clear Water Centrifugal Pump)

1. Self-priming centrifugal pumps are suitable for urban environmental protection, construction, fire-fighting, chemical processing, pharmaceuticals, dyes, textile printing and dyeing, brewing, power generation, electroplating, papermaking, petroleum, mining, equipment cooling, oil tanker unloading, and other applications.

2. Self-priming centrifugal pumps are suitable for clean water, seawater, chemical process fluids with acidic or alkaline characteristics, and general paste-like slurries (with a medium viscosity ≤ 100 centipoise and a solid content of up to 30% or less).

3. When fitted with a rocker‑type spray nozzle, the self‑priming centrifugal pump can also propel water into the air, where it breaks into fine droplets for misting—making it an excellent piece of equipment for farms, nurseries, orchards, and tea plantations.

4. Self-priming centrifugal pumps can be paired with filter presses of any model and specification, making them the ideal pump choice for delivering slurry to the filter press for filtration.

ZX Self-Priming Pump (Self-Priming Clear Water Centrifugal Pump): Malfunctions and Troubleshooting Methods:

The water pump is not delivering water:

1. The pump casing is either empty of priming fluid or contains insufficient priming fluid—add sufficient priming fluid.

2. Air leakage in the suction line—inspect and eliminate the leak.

3. Rotational speed too low — adjust the speed.

4. The suction lift is too high or the suction piping is excessively long—reduce the suction lift or shorten the suction pipe.

5. Excessive leakage from the mechanical seal—repair or replace.

6. The gas in the suction line cannot be discharged from the outlet—ensure it is vented.

Significant noise and vibration:

1. Unstable base—reinforce it.

2. Pump shaft bending—replace or straighten.

3. Cavitation—adjust operating conditions.

4. Severe bearing wear—replace.

5. Foreign matter in the inlet pipeline—remove the foreign matter.

6. For imported electric motors, if the two shafts are not concentric, adjust the coaxiality.

Insufficient water output:

1. The impeller passage and suction pipe are blocked—remove the blockage.

2. Severe wear on the impeller or impeller seal—replace the retaining ring.

3. Insufficient power or excessively low speed—increase the power to the full rating and adjust the speed to the rated value.

Excessive shaft power consumption:

1. Excessive flow rate—Increase the outlet pressure.

2. Rotational speed too high—reduce it appropriately.

3. Pump shaft bending or impeller jamming—replace or straighten.

4. Blockage or entrapment in the pump’s flow passages—remove the obstruction.

ZX Self-Priming Pump (Self-Priming Clear Water Centrifugal Pump): Maintenance and Disassembly/Assembly:

1. When maintaining or overhauling the pump, attention should be paid to several key components.

A. Rolling bearings: After the pump has been in long-term operation, when the bearings have worn to a certain extent, they must be replaced.

B. Front seal ring and rear seal ring: When the seal rings have worn to a certain extent, they must be replaced.

C. Mechanical Seals: Under normal operating conditions, mechanical seals should not be disassembled for inspection as long as no liquid leakage is observed. However, if severe leakage occurs at the drain port on the lower end of the bearing housing, the seal must be removed and inspected. When installing or removing a mechanical seal, handle it with care, ensure that the mating surfaces are clean, and protect the sealing faces of both the stationary and rotating rings; striking or impact is strictly prohibited. The primary cause of leakage in mechanical seals is surface roughening of the friction faces. To remedy this, the end faces of the friction pair can be lapped to restore their mirror‑like finish. Another common cause of leakage is improper installation of the O‑ring seal or its deformation and aging; in such cases, the O‑ring should be adjusted or replaced, followed by reassembly.

2. Pump disassembly and assembly sequence:

A. Remove the motor or disconnect the coupling.

B. Remove the bearing housing assembly and inspect the radial clearance between the impeller and the front wear ring.

C. Remove the impeller nut, pull out the impeller, and inspect the radial clearance between the impeller and the rear seal ring.

D. Loosen the set screws of the mechanical seal, pull out the rotating ring assembly, inspect the mating condition of the end faces of the rotating and stationary rings, and check the sealing integrity of the O-ring.

E. Unscrew the set nut of the coupling and pull out the coupling.

F. Remove the bearing end cover and extract the pump shaft’s bearing.

G. During installation, simply assemble in the reverse order.

Disassembly and assembly sequence for the 150ZX160-75 pump:

1. Remove the motor or disconnect the coupling.

2. Remove the bearing housing assembly, inspect the radial clearance between the impeller and the front wear ring, and check whether the impeller nut is loose.

3. Remove the impeller nut, pull out the impeller, and check the radial clearance between the impeller and the rear seal ring.