Selection depends on your media type and operating conditions:

• MD Series — General media, pH 6.5-8.5, turbidity ≤1.5%
• MDF Series — Corrosive media, pH 3-12, turbidity ≤1.5%
• MDS Series — High-altitude applications (1000-2000m), pH 6.5-8.5, turbidity ≤1.5%
• MD(P) Series — High-turbidity conditions, pH 6.5-8.5, turbidity 1.5%-3%

Determine the flow rate based on required media volume per unit time, then select the number of stages based on head (delivery height, distance, and pipeline losses). Finally, match the required motor power from the performance table.

Our multistage centrifugal pumps cover a flow range of 6-800 m³/h and a head range of 50-1200 m. The speed is typically 2950 r/min or 1480 r/min depending on the model. Specific performance parameters vary by model, number of stages, and impeller diameter.

The maximum operating temperature is 80°C. For standard pumps (MD, MDF, MD(P)), the maximum altitude is 1000m. The MDS series is specifically designed for high-altitude applications up to 2000m. The maximum solids content should not exceed 1.5% (for MD/MDF/MDS) or 3.0% (for MD(P)), with particle diameter less than 0.5mm.

Yes. The MDF Series is specifically designed for corrosive media with a pH range of 3-12. For highly acidic or alkaline conditions, MDF pumps with appropriate material selections are recommended. For general media (pH 6.5-8.5), the standard MD series is sufficient.

The pump foundation must have sufficient strength, with a mass approximately 3-5 times the weight of the pump unit. Use steel shim plates and wedge blocks under the base. After leveling the base and tightening anchor bolts, grout the anchor bolt holes.

The gap between pump and motor couplings should be 3-6mm. The pump and motor shafts must be coaxial. Use a feeler gauge to measure the uniformity of the coupling end face gap (tolerance: 0.06mm). Use a straightedge to measure around the coupling circumference (tolerance: 0.08mm). Adjust with shims if needed.

• Install a pressure gauge, gate valve, and check valve on the discharge port. Install a vacuum gauge and foot valve on the inlet.
• Install a filter screen at the inlet to prevent large particles from entering.
• Do not let pipeline weight rest on the pump.
• The return water pipe and seal water pipe must not be blocked.
• Use pipes no smaller than the pump's inlet/outlet diameter.
• Avoid bends within 1 meter of the pump to reduce resistance loss.
• Flush pipelines before connecting to the pump to prevent weld slag from damaging the impeller.

1. Rotate the coupling by hand — the rotor should turn smoothly without binding.
2. Fill the pump with water or evacuate air from the pump casing. Close the discharge gate valve and pressure gauge cock.
3. Momentarily start the motor to check rotation direction. From the motor side, the pump should rotate clockwise.
4. Start the pump, open the pressure gauge and vacuum gauge cocks, then gradually open the discharge gate valve until the pressure meets requirements.

Slowly close the discharge gate valve and pressure gauge cock, close the vacuum gauge cock on the inlet, then cut off the motor power. Never stop the pump by cutting power while the discharge valve is still open, as this may cause water hammer damage.

Rolling bearing operating temperature should not exceed 35°C above ambient temperature, with a maximum of 75°C. Bearing grease should be replaced every 120 hours of operation. During operation, bearings should not produce abnormal noise. The packing leakage rate should be approximately 10-20 drops per minute — adjust the packing gland if needed.

No. The pump should not run for extended periods with the discharge valve closed or at very small openings, as this causes the pump to heat up and reduces service life. Also, never operate the pump with the suction valve closed, and do not use the suction valve to regulate flow — this will cause cavitation and damage the pump.

• Every 120 hours: Replace bearing lubricating grease.
• Every 1000 hours: Perform a full inspection. Check impeller and seal ring clearance — replace the seal ring if wear exceeds twice the maximum clearance.
• Each shutdown: Rotate the coupling by hand before restarting to check for binding.
• Winter shutdowns: Open all drain plugs at the bottom of the pump to prevent freezing damage.
• Long-term storage: Dismantle the pump, apply anti-rust oil to parts, and store properly.

For winter or temporary shutdowns, drain all water from the pump through the bottom drain plugs to prevent freezing. For long-term storage, completely dismantle the pump, apply anti-rust oil to all machined parts, and store in a dry, clean environment. Protect flanges and openings from contamination.

• Check that base, pump, and motor mounting bolts are tight.
• Check coupling end face gap is not too small.
• Inspect instruments and wiring for damage or aging.
• Check pipelines for leaks or looseness.
• Regularly record pump performance and operating conditions.

This indicates insufficient water filling or air in the suction line. Re-prime the pump, tighten any leaking bolts or cocks, and eliminate air pockets in the suction pipeline.

Common causes: poor bearing lubrication, misalignment between pump and motor shafts, bearing damage, or contamination/water ingress in bearings. Solutions: clean or replace bearings, ensure proper sealing, add appropriate lubricant, and realign the pump and motor shafts.

Possible causes: clogged flow channels or pipelines, excessive seal clearance, insufficient speed, or undersized piping. Clean the pump and pipelines, replace worn seal rings, increase pump speed to design value, or replace undersized pipes.

Causes: excessive flow rate, pump installation height too high causing cavitation, misalignment between pump and motor shafts, damaged coupling elastomer, loose anchor bolts, or bearing damage. Reduce flow rate, lower installation height, realign coupling, replace damaged components, and tighten anchor bolts.

Causes: system head much lower than pump design head, pipeline rupture, discharge valve not closed during startup, shaft misalignment, rubbing between rotating and stationary parts, bearing wear, rotor imbalance, or low voltage. Close the gate valve for debugging, repair pipeline, realign, replace bearings, rebalance rotor, or increase voltage.

Causes: pump and motor shaft misalignment, bent shaft, damaged packing sleeve, improper packing installation, wrong packing type, or impurities between packing and shaft sleeve. Realign shafts, straighten or replace the shaft, polish or replace the sleeve, reinstall packing properly with even pressure, or replace with correct packing material.