A Brief Guide to Progressive Cavity Pumps (PCPs)

A 2024 market analysis by Fortune Business Insights estimates the global PCP market to reach a staggering USD 7.09 billion by 2028, highlighting their rising recognition and significance. However, what makes PCPs so indispensable? This blog explores the ingenious design and operational principles of PCPs. Read on to learn more.

How Does a Progressive Cavity Pump Work?

Progressive cavity pumps (PCPs), offered by leading manufacturers like Hydro Prokav, are a distinct type of positive displacement pumps. Contrary to common belief, PCP operation relies on sealed cavities, similar to piston pumps, ensuring positive displacement.

These pumps use a rotating single-helical rotor within a double-helical elastomeric stator with a specific interference fit to achieve fluid transfer. As the rotor turns, it creates a series of discrete chambers that progress through the pump cavity.

This mechanism delivers two key benefits. Firstly, it offers a constant volumetric flow rate that directly correlates to the rotation speed, even when operating in both directions. Secondly, it causes minimal shear stress on the pumped fluid.

Often, PCPs are the most efficient solution for various industries that require precise metering and gentle pumping of viscous or shear-sensitive materials.

Distinctive Features of Progressive Cavity Pumps

Progressive Cavity Pumps stand out for their unique design, offering a powerful combination of benefits for challenging pumping tasks.

Unmatched Versatility for Viscous Fluids

Unlike centrifugal pumps that struggle with thick liquids, PCPs excel at efficiently transferring fluids across a wide range of viscosities, without compromising efficiency.

Precise Dosing and Metering

The positive displacement design enables PCPs to deliver precise and continuous flow, making them ideal for applications requiring accurate dosing of sensitive and shear-sensitive fluids. This minimizes emulsification and potential damage to the product.

Handles High Solids Content with Ease

PCPs are built to handle fluids with a high content of solids, such as pastes and sludges. This makes them a perfect fit for industries like mining and wastewater treatment, where traditional pumps struggle.

Self-Priming

A significant advantage of PCPs is their self-priming capability. This allows them to efficiently handle air entrainment.

Continuous and Smooth Flow

PCPs allow continuous and smooth flow of fluids. This is essential when transferring fluids that are shear-sensitive, therefore minimizing emulsification and damage to the pump.

Selecting the Right Progressive Cavity Pump

For optimal performance and longevity, selecting the appropriate PCP needs careful consideration of several key factors regarding fluid properties. Here's a quick guide to ensure an effective and reliable selection process:

Abrasion: Highly abrasive fluids are better suited for larger pump models operating at slower speeds. An example of this would be Hydro Prokav’s KDA series pumps with a maximum capacity of 350 m3/hr and designed to operate at slower speeds for handling abrasive fluids. While this might seem like a higher upfront cost, it significantly reduces maintenance requirements and overall lifecycle expenses.
Viscosity: The pump speed should be adjusted based on the fluid's viscosity. Thicker, higher viscosity fluids necessitate slower pump speeds.
Temperature: The stator material selection must be compatible with the anticipated temperature range of the fluid. Since temperature has a direct impact on stator elastomer resiliency, proper material selection is crucial.
Chemical Resistance: The chosen stator material needs to exhibit adequate chemical resistance to the specific properties of the fluid being pumped. Manufacturers like Hydro Prokav offer pump components (stators, rotor MOCs, and stator tubes/pipes) in diverse materials, including elastomers Buna, EPDM, Viton, Hypalon, Hi Nitrile, Natural Rubber, and metallurgies including Cast Iron, Stainless Steel (SS 304, SS 316), Alloy 20, Hastelloy C, Hastelloy B, and Titanium. Additionally, they provide FRP/Ebonite lined housing with rotating parts in Super Alloys for highly corrosive environments.
Joint Selection Based on Fluid and Pressure: The type of joint used in a PCP must be selected based on both the fluid characteristics and the operational pressure of the system. Joints need to ensure a tight seal to prevent leaks and withstand the pressure generated by the pump. This is particularly important in pumps handling volatile or toxic fluids, where leak prevention is critical. Options may include threaded, flanged, or specially designed proprietary joints that offer enhanced durability and reliability under specific operational conditions.

It is vital to carefully evaluate these factors and consult with a qualified PCP supplier, such as Hydro Prokav. This way, you can ensure the selection of a pump that delivers optimal performance, reliability, and cost-effectiveness for your specific application.

Progressive Cavity Pump Applications

Progressive cavity pumps’ unique design and minimal internal recirculation solidify their position as the go-to solution for diverse, demanding fluid transfer applications.. These pumps have several applications across industries:

Food and Beverage: PCPs like Hydro Prokav's KX-F Series (FDA/EHEDG compliant) efficiently transfer viscous ingredients such as syrups, doughs, must, and delicate products like wine and juice at up to 120 m3/hr and 24 bar.
Wastewater Treatment: The KYM Series excels in harsh environments with slurries, sludge, and corrosive liquids due to its robust construction. It delivers high flow rates and pressures for efficient treatment–up to 200 m3/hr and 48 bar, respectively.
Consumer Goods: From personal care products such as lotions and soaps with Hydro Prokav’s KX-F Series to precise metering of electronics materials like soldering pastes with the KX-PK Series, PCPs offer a tailored solution for each requirement.
Metals and Chemicals: PCPs handle abrasive metal slurries, meter electrolytes, and pump viscous resins and polymers or catalyst slurries and ceramic glazes. The KX and KYM Series are useful here.
Biogas Production: Hydro Prokav’s PCPs play a pivotal role in biogas production by efficiently transferring biomass slurry and organic waste materials. Their robust design and low shear operation ensure optimal handling of diverse feedstocks, enhancing biogas yield and process efficiency. These pumps are crucial in maintaining continuous operations, handling varying viscosities and abrasive materials with ease.
Other Industries: PCPs establish themselves as critical assets within industries such as mining and minerals, construction, pharma, paints and explosives, and oil and gas due to their inherently advantageous design principles. A distinct benefit is that manufacturers like Hydro Prokav offer cutting-edge, customizable pump solutions for every application.

Endnotes

In conclusion, progressive cavity pumps provide exceptional adaptability to handle various complex fluids in a variety of sectors. Their distinctive design provides reliable, easy to maintain solutions. As industries expand, their functions will also broaden, ensuring PCPs’ value as a vital tool for management of fluids.

For expert assistance in selecting the right PCP for your specific application, contact Hydro Prokav, a leading manufacturer of progressive cavity pumps.