Progressive cavity pumps are essential in many industries for their ability to transfer viscous fluids and slurries. However, their rotor and stator components are susceptible to wear and failure over time. Let's examine some of the most common reasons for progressive cavity pump failures.Wear and Tear of Key Components

As the rotor and stator work together to progress fluid through the pump, friction causes natural wear over thousands of operating hours. The amount and rate of wear depends on factors like fluid abrasiveness, pressure, and temperature. Pumps handling aggressive chemical mixtures or high solids content slurries will experience more rapid wear of their rotor and stator.As seen in the image above, normal operation gradually degrades rubber stators through microscopic cuts and abrasions. Eventually, the elastomer breaks down to the point of failure. Rotors made of stainless steel or other alloy metals withstand wear better but must still be inspected and replaced periodically. Failure to address normal wear can lead to leakage or total pump failure.

Damage from Abrasive Particles

Pumps transferring fluids with any suspended solids are prone to accelerated wear, as the particles act as tiny grinding wheels between the mating rotor and stator surfaces. Larger solids exceeding the maximum particle size rating for the pump will become lodged and grind away at rubber and metal. Process engineers must closely control solids content and size to avoid abrasion-induced failures of key rotor stator pump components.

Chemical Attack on Materials

The chemical resistance of a pump's materials is crucial in many applications. Exposure to acids, bases, or other corrosive chemicals can quickly degrade unlined stators through chemical etching. Stainless steel rotors are also vulnerable if the fluid falls outside their rated pH tolerance. Too much chemical stress leads to cracking, pitting and eventually complete material dissolution. Proper material selection is important to resist chemical damage and causes of stator failure.

Other Stress Factors

Outside of normal wear processes, several installation and operational errors can prematurely end the life of progressive cavity pump stators. Running a pump dry without fluid exposes the rubber stator to excessive heat buildup. Incorrect rotor insertion or flow imbalances cause uneven loading that fatigues components more rapidly. Improper temperature control of viscous heated transfer can thermally 'fuse' the rotor and stator together. Careful equipment inspection and maintenance is key to avoiding untimely failures through these special stress conditions. Referencing OEM guidelines for screw pump stator and overall pump care is equally important. In conclusion, properly addressing the common causes of failure outlined here through regular maintenance, component inspections and process optimizations can significantly extend the service intervals of stator pumps. Following manufacturers recommendations for progressive cavity pump troubleshooting and causes of stator failure will help keep transfer operations running smoothly. Do not hesitate to contact pump OEMs for guidance specific to your application needs. For more details on the reasons behind damage to the stator of the progressive cavity pump, please refer to causes of stator failure. Proper identification and remediation of failure modes ensures long-term reliability and performance.