Centrifugal pumps play a vital role in many sectors, from petrochemical and power production to water purification and building projects. Their dependability and performance make them the favored option for moving liquids. Yet, like any machinery, they face functional challenges that can hinder output and cause expensive outages. Grasping these typical troubles is important for maintaining extended dependability and overall setup strength.

1. Insufficient Flow or No Flow

Causes of Reduced Flow

Flow troubles in centrifugal pumps frequently arise from flawed setup planning, blocked screens, air mixing, wheel harm, or wrong pump choice. Low Net Positive Suction Head (NPSH) or shut outlet gates can lead to zero or weak flow too.

How to Restore Proper Flow

To fix proper flow, check the intake pipe for clogs or gaps. Also, make sure the wheel shows no wear or breaks. Confirming the pump runs in its Best Efficiency Point (BEP) zone matters greatly. Adding a double-suction wheel can boost flow steadiness. The impeller is of a double-suction, closed design, capable of automatically balancing a significant portion of axial forces.

2. Excessive Vibration

Main Sources of Vibration

Vibration usually comes from poor alignment, uneven spinning parts, cavitation, or tired bearings. It might stem from fluid unrest due to a bad setup or running beyond the BEP zone as well.

Preventing Vibration Through Proper Installation

Good alignment at setup and a sturdy shaft plan are the main steps. The reduced bearing gap and firm shaft cut bending in every working setting, which supports steady pump action. Moreover, a double volute housing setup lessens side forces that trigger shakes. The double volute pump body makes radial force self-balancing, innovative tongue design can minimize radial pressure pulses and vibration.

3. Overheating Issues

What Leads to Pump Overheating

Overheating often happens from bearing breakdowns, missing grease, warm surroundings, or operating the pump without fluid. Engine strains or rubbing among pieces can raise heat levels too.

Cooling and Lubrication Best Practices

Applying suitable grease setups—like fat or light oil—and watching heat caps aids in stopping overheating. Grease lubrication is the standard configuration; thin oil lubrication is optional. Using forced lubrication bearings with temperature monitoring instruments further enhances safety under demanding conditions.

4. Seal and Leakage Failures

Why Seals Fail in Centrifugal Pumps

Seal breakdowns can occur from wrong stuff picks, heat growth mismatches, rough bits in the liquid, or bad lineup during build.

Preventing Leaks with Correct Seal Selection

Picking seals that fit API682 rules guarantees a match with risky or hot substances. Mechanical seal chamber size conforms to IS021049 (API682). Tailoring seals based on liquid traits and working states improves lasting output.

5. Cavitation Damage

Identifying Signs of Cavitation

Usual clues include sounds like stones in the pump, shake jumps, dropped output, and hole marks on wheels.

How to Avoid Cavitation in Operation

Guarantee enough NPSH by dropping the intake height or boosting the intake push. Employing specially designed impellers improves cavitation resistance. Excellent blade hydraulic design ensures high pump efficiency and, low cavitation margin.

6. Motor Overload Problems

Reasons Behind Motor Overload

Motor strains might result from too much setup head force, wrong engine sizing, power imbalance, or binding inside the pump.

Electrical and Mechanical Checks

Review power feed steadiness and align engine grades with setup needs. Physically look for worn bearings or poor alignment that could add load on the engine.

Longgang Product Solutions for Common Issues

Longgang provides a full lineup of tailored centrifugal pumps built to tackle these usual working troubles with top engineering fixes.

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LBD(BB2)-Radial Dissection Chemical Process Centrifugal Pump

This group of sturdy petrochemical process pumps is horizontal, radially split designed in accordance with APl610 11th “Centrifugal Pumps for the Petroleum Industries”. Its centerline mounting ensures thermal stability while dual-end support enhances performance under high-temperature conditions. The double volute structure minimizes radial forces for extended bearing life—a key factor in reducing vibration-related failures.

Longgang LDD(BB4)-High-Pressure Segmented Multi-Stage Centrifugal Pump

LDD series segmental-ring multistage pumps are in accordance with the latest edition of API610 pumps offer high efficiency and good cavitation performance. With options for single- or double-suction first-stage impellers depending on NPSH requirements and advanced balancing mechanisms that eliminate axial force on bearings during operation, this model excels under high-pressure applications without overheating risks.

The LDD’s robust bearing options include ZH sliding bearings and ZQ forced lubrication systems equipped with temperature protection sensors—ideal for continuous-duty operations where cooling is critical.

Longgang LDT(VS6)-Vertical Suspended Bag Centrifugal Pump

Designed specifically for handling volatile media like ethylene or propane under cryogenic conditions, the first stage impellers perform excellently in cavitation while back-to-back thrust ball bearings ensure axial stability at all times. The vertical suspended model features multi-point support structures that comply with API610 standards—making it ideal for underground installations requiring minimal maintenance access points.

All Longgang products support fully customized configurations based on your operational needs—from flange orientation down to seal material selection—ensuring optimal performance regardless of complexity.

Maintenance Tips for Longevity

Routine Inspection Checklist

• Check alignment between motor and pump
• Inspect seals for leaks
• Monitor bearing temperatures
• Verify NPSH conditions
• Clean suction strainers regularly
• Listen for unusual noises indicating cavitation or wear

Routine inspections help detect early signs of failure before they escalate into costly breakdowns.

Recommended Service Intervals

Service intervals depend on application severity, but typically include:

• Monthly: Visual inspections
• Quarterly: Lubrication checks
• Annually: Bearing replacement & seal examination

Using pumps like Longgang’s LAD series simplifies maintenance tasks thanks to their modular design: Bearings, mechanical seals can be replaced without moving the pump case.

By understanding these common centrifugal pump problems—and choosing reliable customized solutions like those offered by Longgang—you ensure safer operations while maximizing equipment lifespan across diverse industrial applications.

FAQ

Q: What causes a centrifugal pump to lose prime?

A: Loss of prime often results from air leaks in suction lines or an empty suction tank, preventing fluid intake into the impeller eye.

Q: How do I know if my centrifugal pump is cavitating?

A: You’ll hear loud rattling noises similar to marbles hitting metal inside your pump; this indicates vapor bubbles collapsing inside due to low inlet pressure conditions.

Q: Can I run a centrifugal pump dry?

A: No—dry running damages seals and overheats bearings quickly since there’s no liquid medium for cooling or lubrication inside the casing.

Q: What maintenance does a centrifugal pump need?

A: Regular inspection of seals/bearings/lubrication systems, along with alignment checks, ensures optimal performance; customized service intervals depend on usage frequency and operating environment.