Progressive Cavity Pumps

Progressive cavity pumps—also known as PC pumps, helical rotor pumps, or eccentric screw pumps—are positive displacement pumps designed for smooth, low-pulsation transfer of difficult fluids. They are widely used for viscous liquids, shear-sensitive products, slurries and solids-bearing media, and for duties that need accurate, speed-controlled flow. AxFlow UK supplies a comprehensive range of NOV Mono progressive cavity pumps, including maintain-in-place EZstrip designs, compact industrial ranges and hygienic stainless-steel options.

How do progressive cavity pumps work?

A progressive cavity pump uses a single-helix metal rotor that rotates eccentrically inside a double-helix elastomer stator. As the rotor turns, sealed cavities form and progress from suction to discharge, moving a fixed volume per revolution. Because flow is proportional to speed, PC pumps are easy to control with gearboxes or variable speed drives and deliver low shear with minimal pulsation.

ADVANTAGES OF PROGRESSIVE CAVITY PUMPS 

• Smooth, low-pulsation flow for stable transfer and process control
• Gentle pumping action suited to shear-sensitive fluids and fragile solids (application dependent)
• Excellent for viscous and non-Newtonian media where centrifugal pumps struggle
• Solids handling capability for slurries and sludge duties (range and configuration dependent)
• High differential pressure capability for longer transfer distances (range dependent)
• Variable speed control enables accurate dosing and metering-style transfer
• Good suction performance and self-priming characteristics (duty dependent)

Progressive Cavity pump APPLICATIONS 

Progressive cavity pumps are often used where other industrial pumps struggle, especially when a fluid must be handled gently, contains solids, and/or has high viscosity. Common uses include:

• Pumping, dosing, and metering chemicals where accuracy is required. 
• Hygienic environments and/or shear sensitive fluids such as in the food, drink and cosmetics industry. 
• Pumping materials that contain abrasive particles such as wastewater management and pumping sewage, sludge or slurry. 
• Pumping heavy or viscous fluids such as oil and chemicals. 
• Applications that require varied flow rates.

IMPORTANT CONSIDERATIONS WHEN SELECTING Progressive Cavity PUMPs

Progressing cavity pumps differ fundamentally from one another depending on the industrial application. The components are available in different materials and designs to best suit the specific application or fluid requirements. A list of important things to consider are:

• Fluid name, concentration and temperature range (including start-up/upset)
• Required flow range and whether speed control is needed
• Differential pressure (including cold start, line losses and pressure spikes)
• Viscosity range and whether the fluid is shear-sensitive
• Solids content, particle size and abrasiveness (if applicable)
• Suction conditions (flooded suction vs lift, line length/diameter, air ingress risk)
• Installation constraints (horizontal/vertical, hopper/auger feeding, space limits)
• Any ATEX or site standards requirements

Important Cavity Pump limitations (to protect pump life)

Progressive cavity pumps must not be run dry and must not pump against a closed discharge. Where risk exists, specify dry-run protection (e.g., stator temperature monitoring) and appropriate pressure protection/relief.

WHY BUY PROGRESSIVE CAVITY PUMPS FROM AXFLOW

AxFlow UK represents Mono progressive cavity pumps that have over 70 years experience.The progressive cavity pump principle is ideal for handling liquids that can be slurries, viscous, shear sensitive, 2 or 3 phase mixtures or when applications require, significant suction lift capabilities. The heart of the Progressive Cavity pump is the rotor and stator. As the single helix rotor revolves eccentrically within the double helix of the stator, a continuous cavity is formed and progresses towards the discharge end of the pump as the rotor rotates

Progressive Cavity Pump Maintenance

It is ideal to check a progressive cavity pump for wear after roughly 700-1000 operating hours. The frequency of subsequent inspections is determined in relation to the degree of wear noted. It is suggested that the interval between inspections must however, not surpass 1500 operating hours.