Product Description
Model Code Explanation
Product Introduction
ZXL close-coupled self-priming clean water centrifugal pump is a self-priming centrifugal pump. It features a compact structure, easy operation, smooth running, convenient maintenance, high efficiency, long service life, and strong self-priming capability. There is no need to install a bottom valve in the pipeline. Before operation, it is only necessary to retain a certain amount of priming liquid inside the pump casing. This simplifies the pipeline system and improves working conditions.
Applications
1. Suitable for municipal environmental protection, construction, fire-fighting, chemical industry, pharmaceutical, dyes, printing and dyeing, brewing, electric power, electroplating, paper-making, petroleum, mining, equipment cooling, oil tanker unloading, etc.
2. Suitable for clean water, seawater, chemical media liquids with certain acidity or alkalinity, and general paste-like slurry (medium viscosity ≤ 100 cP, solid content up to 30% or below).
3. When fitted with a rocker-type sprinkler, water can be sprayed into the air and dispersed into fine droplets for irrigation. It is an excellent machine for farms, nurseries, orchards, and tea plantations.
4. Can be used together with any type and size of filter press, delivering slurry to the filter press. It is an ideal matching pump for filter press systems.
Operating Conditions
All ZXL close-coupled self-priming clean water pumps adopt a pump casing design with axial liquid return. The pump casing consists of a suction chamber, liquid storage chamber, volute chamber, return hole, and gas-liquid separation chamber. After the pump is started, the impeller draws in both the liquid stored in the suction chamber and the air in the suction pipeline, and they are fully mixed in the impeller. Under the action of centrifugal force, the liquid carrying the gas flows toward the outer edge of the volute chamber, forming a white foam belt of a certain thickness and a high-speed rotating liquid ring at the impeller outer rim. The gas-liquid mixture passes through the diffuser into the gas-liquid separation chamber. At this point, due to the sudden decrease in flow velocity, the lighter gas separates from the mixture and is discharged through the discharge port of the pump casing. The degassed liquid returns to the liquid storage chamber and re-enters the impeller through the return hole, where it mixes again with the air drawn from the suction pipeline inside the impeller. Under the action of the high-speed rotating impeller, the mixture once again flows toward the impeller outer rim. As this process repeats, the air in the suction pipeline is continuously reduced until all the air is exhausted and the self-priming process is completed, after which the pump enters normal operation.
On some pumps, a cooling chamber is provided at the bottom of the bearing housing. When the bearing temperature rises and the housing temperature exceeds 70°C, cooling liquid can be introduced into the cooling chamber through either of the cooling pipe connections to circulate and cool the unit. The internal sealing mechanism that prevents liquid from leaking from the high-pressure area to the low-pressure area consists of the front and rear seal rings. The front seal ring is installed on the pump casing and the rear seal ring is installed on the bearing housing. After long-term operation, when the seal rings are worn to a certain extent and affect the pump efficiency and self-priming performance, they should be replaced.
Structure Diagram
|
1
|
Coupling
|
2
|
Pump Shaft
|
3
|
Bearing
|
4
|
Mechanical Seal
|
5
|
Bearing Housing
|
6
|
Pump Casing
|
7
|
Discharge Base
|
|
8
|
Suction Base
|
9
|
Front Seal Ring
|
10
|
Impeller
|
11
|
Rear Cover
|
12
|
Water Deflector Ring
|
13
|
Filling Port
|
14
|
Return Port
|
Performance Parameters
|
Model
|
Inlet
|
Outlet
|
Suction Lift
|
Motor Power
|
Flow Rate
|
Head
|
|
(mm)
|
(mm)
|
(m)
|
(kW)
|
(m3/h)
|
(m)
|
|
|
25ZXL3.2-20
|
25
|
25
|
6.5
|
0.75
|
3.2
|
20
|
|
25ZXL3.2-32
|
25
|
25
|
6.5
|
1.1
|
3.2
|
32
|
|
40ZXL6.3-20
|
40
|
32
|
6.5
|
1.1
|
6.3
|
20
|
|
40ZXL10-40
|
40
|
40
|
6.5
|
4
|
10
|
40
|
|
50ZXL15-12
|
50
|
50
|
6.5
|
1.5
|
15
|
12
|
|
50ZXL18-20
|
50
|
50
|
6.5
|
2.2
|
18
|
20
|
|
50ZXL12.5-32
|
50
|
50
|
6.5
|
3
|
12.5
|
32
|
|
50ZXL20-30
|
50
|
50
|
6.5
|
4
|
20
|
30
|
|
50ZXL14-35
|
50
|
50
|
6.5
|
4
|
14
|
35
|
|
50ZXL10-40
|
50
|
50
|
6.5
|
4
|
10
|
40
|
|
50ZXL12.5-50
|
50
|
50
|
6.5
|
5.5
|
12.5
|
50
|
|
50ZXL15-60
|
50
|
50
|
6.5
|
7.5
|
15
|
60
|
|
50ZXL20-75
|
50
|
50
|
6.5
|
11
|
20
|
75
|
|
Model
|
Inlet
|
Outlet
|
Suction Lift
|
Motor Power
|
Flow Rate
|
Head
|
|
(mm)
|
(mm)
|
(m)
|
(kW)
|
(m3/h)
|
(m)
|
|
|
65ZXL30-15
|
65
|
50
|
6.5
|
3
|
30
|
15
|
|
65ZXL25-32
|
65
|
50
|
6
|
5.5
|
25
|
32
|
|
80ZXL35-13
|
80
|
80
|
6
|
2.2
|
35
|
13
|
|
80ZXL43-17
|
80
|
80
|
6
|
4
|
43
|
17
|
|
80ZXL40-22
|
80
|
80
|
6
|
5.5
|
40
|
22
|
|
80ZXL50-25
|
80
|
80
|
6
|
7.5
|
50
|
25
|
|
80ZXL50-32
|
80
|
80
|
6
|
7.5
|
50
|
32
|
|
80ZXL60-55
|
80
|
80
|
6
|
18.5
|
60
|
55
|
|
80ZXL60-70
|
80
|
80
|
6
|
22
|
60
|
70
|
|
100ZXL100-20
|
100
|
80
|
6
|
11
|
100
|
20
|
|
100ZXL100-40
|
100
|
100
|
6
|
18.5
|
100
|
40
|
|
100ZXL100-65
|
100
|
100
|
6
|
30
|
100
|
65
|
|
100ZXL70-75
|
100
|
100
|
6
|
30
|
70
|
75
|
|
Model
|
Inlet
|
Outlet
|
Suction Lift
|
Motor Power
|
Flow Rate
|
Head
|
|
(mm)
|
(mm)
|
(m)
|
(kW)
|
(m3/h)
|
(m)
|
|
|
150ZXL170-55
|
150
|
150
|
5
|
45
|
170
|
55
|
|
150ZXL170-65
|
150
|
150
|
5
|
55
|
170
|
65
|
|
150ZXL160-80
|
150
|
150
|
5
|
55
|
160
|
80
|
|
200ZXL400-32
|
200
|
200
|
5
|
55
|
400
|
32
|
|
200ZXL280-63
|
200
|
200
|
5
|
90
|
280
|
63
|
|
200ZXL350-65
|
200
|
200
|
5
|
110
|
350
|
65
|
|
250ZXL550-32
|
250
|
250
|
5
|
75
|
550
|
32
|
|
250ZXL400-50
|
250
|
250
|
5
|
90
|
400
|
50
|
|
250ZXL450-55
|
250
|
250
|
5
|
110
|
450
|
55
|
|
250ZXL400-75
|
250
|
250
|
5
|
132
|
400
|
75
|
|
300ZXL600-32
|
300
|
300
|
5
|
90
|
600
|
32
|
|
300ZXL500-50
|
300
|
300
|
5
|
110
|
500
|
50
|
|
300ZXL550-55
|
300
|
300
|
5
|
132
|
550
|
55
|
Operation (I) Preparation and Inspection Before Start-up
1. For this series of self-priming pumps, depending on operating conditions, high-quality calcium-based grease and No.10 mechanical oil are used for lubrication. For pumps using grease lubrication, grease should be periodically added into the bearing housing. For pumps using oil lubrication, top up the oil if the oil level is insufficient.
2. Check whether the liquid stored in the pump casing is higher than the upper edge of the impeller. If not, priming liquid should be added directly into the pump casing through the filling port on the casing. The pump must not be started when the stored liquid is insufficient, otherwise the pump will not work properly and the mechanical seal may be damaged.
3. Check whether there is any rubbing or collision in the rotating parts of the pump.
4. Check whether the nuts at the pump base and all connecting positions are loose.
5. Check the concentricity and parallelism between the pump shaft and the motor shaft.
6. Check whether the suction pipeline leaks air. If there is any air leakage, it must be eliminated.
7. Open the valve in the suction pipeline and slightly open (not fully open) the discharge control valve.
(II) Start-up and Operation:
1. Jog the self-priming pump and check whether the rotation direction of the pump shaft is correct.
2. Pay attention to any abnormal noise or vibration during rotation.
3. Observe the readings of the pressure gauge and vacuum gauge. After start-up, when the readings of the pressure gauge and vacuum gauge fluctuate for a period and then become stable, it indicates that the pump has been fully primed and has entered normal liquid delivery operation.
4. During the self-priming process, i.e. before the pump enters normal liquid delivery, special attention should be paid to the temperature rise of the liquid inside the pump. If this process is too long and the liquid temperature becomes too high, stop the pump and check the cause.
5. If excessive liquid temperature inside the pump causes difficulty in self-priming, the pump can be stopped temporarily. Let the liquid in the discharge pipeline flow back into the pump, or add liquid directly into the pump through the filling port on the casing to lower the temperature, and then restart the pump.
6. If strong vibration and noise occur during operation, the pump may be cavitating. There are two main reasons for cavitation: excessive flow rate in the suction pipeline and excessive suction lift. When the flow rate is too high, adjust the discharge control valve to increase the pressure gauge reading. If there is blockage in the suction pipeline, the blockage should be removed in time. If the suction lift is too high, the installation height of the pump should be appropriately reduced.
7. If the pump stops due to any reason during operation and needs to be restarted, the discharge control valve should be slightly open (not fully closed). This is helpful for discharging air from the discharge port during self-priming and also ensures that the pump starts under a lighter load.
8. Check whether there is any leakage in the pipeline system.
(III) Shut-down:
1. First close the gate valve on the discharge pipeline.
2. Stop the pump.
3. In cold seasons, drain the stored liquid in the pump casing and the water in the cooling chamber of the bearing housing to prevent parts from freezing and cracking.
Maintenance and Service
This pump is characterized by a simple and reliable structure and durable performance. Under normal conditions, it generally does not require frequent disassembly for maintenance. When a fault is found, it can be eliminated at any time.
1. Pay attention to the following key parts during maintenance:
A. Rolling bearings: After long-term operation, when the bearings are worn to a certain extent, they must be replaced.
B. Front and rear seal rings: When the seal rings are worn to a certain extent, they must be replaced.
C. Mechanical seal: If the mechanical seal does not leak, it generally does not need to be disassembled for inspection. If serious leakage occurs at the drain port at the lower end of the bearing housing, the mechanical seal should be disassembled and inspected. When disassembling and assembling the mechanical seal, handle it with care, keep the mating surfaces clean, protect the mirror surfaces of the stationary and rotating rings, and avoid impacts. Leakage caused by the mechanical seal is mainly due to scratching of the lapped mirror surfaces. The remedy is to lap the end faces again to restore the mirror surface. Another cause of leakage is improper installation, deformation, or aging of the O-ring (or buffer pad). In this case, the O-ring must be adjusted or replaced and reassembled.
2. Pump Disassembly Sequence:
A. Remove the motor or disengage the coupling.
B. Remove the bearing housing assembly, check the radial clearance between the impeller and the front wear ring, and check whether the impeller nut is loose.
C. Unscrew the impeller nut and pull out the impeller, then check the radial clearance between the impeller and the rear seal ring.
D. Loosen the set screws of the mechanical seal and pull out the rotating part of the mechanical seal. Check the contact condition of the end faces of the rotating and stationary rings, and check the sealing condition of the O-ring (or buffer pad).
E. Unscrew the coupling fixing nut and pull out the coupling.
F. Remove the bearing end cover and take out the bearings from the pump shaft.
G. During assembly, proceed in the reverse order.
Installation
1. When the pump is directly coupled to the motor, attention must be paid to the concentricity between the pump shaft and the motor output shaft. The accuracy of installation has a great influence on the smooth operation and service life of the pump, so the installation and alignment must be carried out carefully.
2. The pump coupling must be firmly fastened with bolts and the nuts must be locked to prevent them from loosening, otherwise axial movement of the impeller and mechanical failure may occur.
3. To ensure that a certain amount of stored liquid can be maintained in the pump casing, so as to obtain good self-priming performance and prevent dry friction of the mechanical seal, the pump suction port must be higher than the pump shaft centerline.
4. Notes for installation of the suction pipeline:
A: The installation height of the suction inlet must not exceed 3.5 m. Where conditions permit, the suction inlet should be as far below the lowest water level of the storage tank as possible, and the length of the suction pipeline should be minimized with fewer elbows. This helps shorten the self-priming time and improve self-priming performance.
B: Valves, flanges, and other components in the suction pipeline must be strictly prevented from air leakage or liquid leakage. There must be no air leakage in the suction pipeline.
C: To prevent solid foreign bodies from entering the pump casing, a strainer should be installed on the suction pipeline. The effective flow area of the strainer should be 2–3 times the cross-sectional area of the suction pipeline. The strainer should be inspected regularly.
D: The suction pipeline and discharge pipeline must have their own supports. The pump itself must not bear the load of the pipelines.
5. During installation, the static grounding resistance of the pump and pipelines must meet the specified requirements.
6. During installation, strictly check that the static grounding resistance of the pump casing and pipelines meets the specified requirements.
7. Align the installation gap and concentricity of the pump coupling and motor coupling. The allowable deviation in non-concentricity is 0.1 mm. Any height difference between the pump shaft and motor shaft can be adjusted by inserting copper or iron shims under the base.
8. After the unit has actually run for 3–4 hours, perform a final inspection. If there is no abnormal phenomenon, the installation is considered satisfactory. During the test run, check the bearing temperature. The temperature of the bearing housing should not exceed 70°C.
9. For pumps whose bearing housing is equipped with a cooling chamber, the cooling water connections are designed for rubber or plastic hoses with an inner diameter of Φ12 mm. The thread size is M12×1.25.
10. If a check valve is installed in the discharge pipeline and air cannot be smoothly discharged during self-priming, a small vent pipe and valve should be installed at the discharge port of the pump.
OEM & Custom Solutions
We offer OEM and ODM services, including customized materials, different voltage and frequency motors, special flange standards, customized colors, logo printing and export-oriented packaging solutions to meet various project requirements.
FAQs for Overseas Buyers
1. What liquids can the ZX / ZXL pump handle?
The pump is mainly designed for clean water or liquids with similar physical properties without large solid particles.
2. Does the pump need a bottom valve?
No. After initial filling, the pump has self-priming capability and does not require a bottom valve.
3. What is the maximum medium temperature?
Generally 0–80°C for clean water applications. Please contact us for higher temperature options.
4. Can it be used for agricultural irrigation?
Yes. It is widely used for farmland irrigation, garden watering and small-scale water transfer.
5. Is installation complicated?
No. With compact structure, the pump is easy to install and requires simple pipeline layout.
6. What is the normal delivery time?
Usually 7–15 days depending on order quantity and customization requirements.
7. Are spare parts available?
Yes. We provide impellers, mechanical seals, seal rings and bearings for long-term maintenance support.