Summary
- Typical failures of a centrifugal pump: criticality and an integrated approach to prevention
- Dry Marcia: why it's a problem and how to counter it
- Cavitation: The Invisible Degradation That Erodes Efficiency
- Shut off: the insidious fault due to a closed valve
- CDR Pompe: Reliability, Expertise, and Innovation to Combat Common Centrifugal Pump Failures
As critical components for fluid transfer in sectors such as chemical, the petrochemical and the water treatment, a company is not only responsible for choosing a good pump, but also for being able to read wear signals in advance, predict critical contexts, and set up the right operating conditions. Typical failures of a centrifugal pump, such as Dry marcia, cavitation, and shut-off, These aren't just operational glitches: they are symptoms of a mechanical, thermal, or hydraulic imbalance that often stems from suboptimal design choices, a lack of monitoring systems, or out-of-spec operating cycles.
In-depth analysis of these operational criticalities means learning to prevent them with technical precision, avoiding the progressive degradation of impellers, seals, bushings, and magnetic supports. It also means, design more intelligent systems that can protect themselves thanks to the integration of sensors, advanced materials, and electronic controls.
In CDR We are very familiar with the typical failures of a centrifugal pump, and our departments are continuously working to ensure products that are increasingly safe, resistant, and efficient.
Typical failures of a centrifugal pump: criticality and an integrated approach to prevention
It's important to know that these two faultsdry cleaning, cavitation, and shut-off often they do not manifest as isolated phenomena.
For example, a plant subject to cavitation it may encounter dry running due to a consequent lack of circulating fluid in the system; similarly, valve malfunction in suction, it can generate conditions that anticipate a dry running failure.
The best form of prevention for any type of technical or mechanical failure therefore consists in careful design and timely monitoring of the plantthe use Level detection systems, energy absorption systems, and bypass valves constitute a structured strategy to prevent uncontrolled increases in pressure, temperature, consumption, and internal degradation.
Dry Marcia: why it's a problem and how to counter it
Dry running is one of the typical failures of a centrifugal pump. This condition occurs when the pump works without liquid or with inadequate lubrication. Under these conditions, the pump loses necessary cooling and internal components, usually lubricated, experience direct friction, resulting in overheating.
Most pumps, including the CDR models, they are not designed for this scenario: some configurations with excellent tolerance, such as those made of diamond silicon carbide or graphite, can accept brief episodes without liquid, but these are not alternatives to correct design and use.
Typical consequences include increased electrical absorption until the thermal breaker trips, deformation of internal plastic components, and, in more severe cases, breakage of the bushing itself due to severe friction. Prolonged dry running can also lead to total pump failure.
To avert serious failures such as running dry, it becomes essential integrate control systems such as supply pressure gauges, flow meters, and level sensors that detect the absence or shortage of fluid. Additionally, the installation of equipment such as Wattmetric relays it's an additional level of protection, as they detect abnormal increases in power consumption, a sign of possible dry running.
Cavitation: The Invisible Degradation That Erodes Efficiency
The cavitation represents one of the most feared failures for a centrifugal pump. It occurs when the pressure in the intake duct drops below the fluid's vapor pressure, causing the formation of vapor bubbles: As pressure increases, these bubbles implode, generating micro-shocks that become highly erosive to internal components. Cavitation in a pump can have enormous consequences such as high vibrations and a significant reduction in operational efficiency, with major impacts on flow rate and prevalence. Structurally, implosions can erode the blades of rotating and damage seals and housings, resulting in sudden and costly failures.
One of the most effective ways to prevent and control cavitation is to rely on the parameter NPSH, or Net Positive Suction Head. The ideal condition is that the available NPSH (NPSHa) — determined by the pressure at the suction point, pipe losses, and fluid temperature — consistently exceeds the NPSH (NPSHr) required by the pump. To ensure this margin, solutions range from reducing head losses in the suction piping to optimally positioning liquid sources (e.g., tanks placed at a height relative to the pump), up to the possible integration of boosters or inducers.
Shut off: the insidious fault due to a closed valve
Closing the valve, or closing the feed valve while the pump is running, is another typical characteristic of a centrifugal pump that can lead to significant malfunctions. The shut-off head provides that the fluid, unable to flow in the discharge line, begins to recirculate internally within the pump. This results in an increase in internal temperature and progressive vaporization of the liquid. This condition can be caused by:
- from closing the discharge valve during pump operation;
- a pressure drop on the upper supply line compared to the head the pump should have.
Although not as immediate as in dry marching, the final result is similar: Overheating and loss of lubrication damage plastic components, while bearings and bushings progressively yield until they break. The implementation of a bypass or pressure switches is one of the most effective technical-structural solutions to prevent irreversible damage.
CDR Pompe: Reliability, Expertise, and Innovation to Combat Common Centrifugal Pump Failures
Thanks to a technical consulting service advanced, CDR Pump assists in choosing the most correct setup, in optimal installation, and in implementing the best failure prevention strategies. Our product range is specifically designed to work in harsh environments and offers various special configurations. such as diamond silicon carbide and the continuous development of new materials like zirconium oxide.
The after-sales service also, Planned maintenance and predictive analytics, fundamental tools for preventing the main problems of centrifugal pumps, reducing downtime and ensuring operational continuity.
If you'd like a specific assessment of your system, or a quote for a custom-made solution, our experts are ready to assist: contact us to have all the necessary information on how to avoid typical centrifugal pump failures and the best configurations for your system.