FluidTech News

 Submersible Pump Cable Sealing and Waterproof Connectors: Common Risks and Inspection Methods Submersible pumps operate in environments where electrical components are continuously exposed to water and moisture. Therefore, reliable cable sealing and waterproof connections are essential for protecting the motor and maintaining safe operation. In some applications, a submersible pump may experience insulation resistance deterioration, electrical protection trips, or starting problems after a period of operation. Interestingly, the cable outer sheath may appear undamaged, with no obvious signs of water leakage around the connection. Why can water enter a submersible pump cable connection even when its external appearance seems normal? What should maintenance personnel inspect to prevent water ingress? 1. Why Is Cable Sealing Important for Submersible Pumps? The power cable enters the motor through a dedicated cable entry structure. This connection must provide reliable electrical ins...

 How Do Suction Pipe Diameter and Piping Resistance Affect Metering Pump Performance? In water treatment, chemical dosing, and industrial fluid handling systems, a metering pump's actual dosing performance depends not only on its stroke length and operating frequency but also on the design of the suction piping. Some dosing systems experience unstable liquid intake, reduced flow rates, or air accumulation even though the metering pump itself appears to be operating normally. In many cases, the problem may be related to an undersized suction pipe or excessive resistance in the suction line. How do suction pipe diameter and piping resistance affect metering pump performance? What should be considered when designing a reliable suction system? 1. Why Is Suction Pipe Diameter Important? A metering pump is a positive displacement pump that draws liquid into its pump head through periodic changes in chamber volume. During the suction stroke, the pump needs to receive sufficient liquid to ...

 Long Shaft Sump Pump Shaft Straightness: Why It Matters for Stable Operation Long shaft sump pumps are widely used in chemical processing, wastewater treatment, industrial liquid transfer, and storage tank applications. Their motor is usually installed above the liquid level, while the pump assembly operates below it. A long shaft connects the motor to the submerged impeller. This design allows the pump to handle applications where the liquid level or installation depth makes a conventional horizontal pump unsuitable. However, the extended shaft also makes shaft straightness, alignment, and assembly quality important factors in reliable operation. When a long shaft sump pump develops excessive vibration, abnormal noise, or repeated bearing wear, the impeller and bearings are often inspected first. However, the condition of the long shaft and the complete shaft assembly should not be overlooked. Why does shaft straightness matter, and what should be checked during maintenance? 1. W...

Gear Oil Pump Startup Preparation After Long-Term Shutdown: Lubrication and Maintenance Checklist Gear oil pumps are widely used in industrial lubrication systems, fuel transfer, and other liquid handling applications. In some facilities, pumps may remain idle for weeks or even several months due to production shutdowns, seasonal operation, or standby requirements. When the equipment is put back into service, some operators simply reconnect the power supply and start the pump, assuming that it will operate normally because it worked properly before shutdown. However, long periods of inactivity can affect lubrication conditions, sealing components, bearings, and piping systems. Without proper preparation, a gear oil pump may experience difficult starting, abnormal noise, delayed pressure buildup, or premature component wear. So, what should be checked before restarting a gear oil pump after an extended shutdown? 1. Why Does a Gear Oil Pump Need Inspection After Long-Term Shutdown? A gea...

 How to Check Mechanical Seal Dimensions and Structure When Replacing a CDLF Vertical Multistage Pump Seal? CDLF vertical multistage pumps are widely used in industrial water supply, pressure boosting, boiler feed systems, and water treatment applications. After extended operation, the mechanical seal may develop leakage due to wear, aging, unsuitable operating conditions, or damage to sealing components. Replacing the mechanical seal is therefore an important part of pump maintenance. However, selecting a replacement seal is not simply a matter of matching the pump series name. Incorrect dimensions or structural differences may cause installation difficulties and repeated leakage. So, what should be checked when replacing a mechanical seal in a CDLF vertical multistage pump? 1. Why Is the Pump Model Alone Not Enough? CDLF is a product series covering different pump sizes and configurations. Mechanical seal specifications may vary depending on the pump model, shaft arrangement, and...

A worn wear ring can reduce a centrifugal pump’s useful output without producing an external leak. The change takes place inside the pump: an enlarged running clearance may allow more liquid to return from a higher-pressure region to a lower-pressure region. This discussion applies to pumps fitted with the relevant wear-ring arrangement. Ring locations and replaceable components differ between designs. Do not assume every centrifugal pump has the same suction-eye arrangement or replacement limits. Where the loss occurs At a typical impeller-eye wear-ring interface, the running clearance limits internal leakage while allowing the rotating and stationary parts to operate without contact. Under otherwise comparable conditions, an enlarged clearance generally increases leakage. Some liquid that has already received energy passes back through the gap and must be handled again instead of becoming useful discharge flow. Volumetric losses therefore increase. The accompanying photograph sho...