Last updated on June 4th, 2021
The machine is a type of positive displacement pump designed to handle extreme substances. It is used for artificial lift and can lift challenging substances such as heavy oil, gassy wells, high sand production and more. It’s a super versatile pump that can actually take on a wide range of jobs, although it is best suited to metering chemicals and pumping viscous, abrasive, or shear-sensitive materials.
As a positive displacement pump, PCP’s create a flow as its main use. They are able to move fluid at a regulated speed even if the substance its dealing with increases in pressure or is particularly viscous. These pumps are used to pull extreme liquids through its suction inlet and into an elongated casing. Inside this casing, there is a helical rotor that is offset to a stator assembly.
The rotor turns and works the stator assembly, as a result, small cavities start to form. The liquids being pulled through the suction inlet and into the casing then progress through the cavities and are exited via the discharge outlet.
Some examples of the substances pumped through a progressive cavity pump are:
- metering and dosing
- chemical manufacturing
- oil pumping/petroleum production
- food and beverage processing
- pulp and paper
- environmental technology
- grout or cement pumping
- lubrication oil pumping
- limited energy well water pumping
- sewage, sludge, and slurry pumping
Are progressive cavity pumps self priming?
Progressive cavity pumps have a much higher pressure rate than most other positive displacement pumps. They also have a super high suction lift. What’s super impressive about them though, is their ability to self-prime. As a result of the tight tolerances in its construction, a progressive cavity pump has a very high suction that allows for priming capabilities of up to 8M.
Due to its self-priming capabilities, PCP’s can handle gas slugs for as long as 30 minutes before struggling. The only issue is depending on the machine model, the priming fluid can take a little while to get to the rotator and stator so will require manual lubrication or charging with duty fluid.
Can a progressive cavity pump run dry?
Progressive cavity pumps cannot generally be run dry. This is because the heat generated by the rotor and stator that this would generate will likely cause the pump to fail. In fact, lots of PCP’s come with additional accessories designed to combat this issue and protect the machine’s longevity.
Progressive cavity pumps need to be protected from dry-running because this would damage the machine by causing friction between the rotor and stator causing the temperature of the internal surface of the stator to quickly rise and break the machine.
Can progressive cavity pumps pump water?
Progressive cavity pumps are praised for their ability to handle even the most viscous of materials. So, of course they can pump water with ease.
Here’s a list of some of the substances that PCP’s can pump:
- Wine – grape pressing, wine filtering and more
- Edible oil – liquids such as oil extraction, oil separator feed, filter press feed, crusher feed and more can also be pumped by CPC’s
- Paper and pulp – recycled paper transfer, pulp transfer, filler transfer, etc.
- Wastewater – PCP’s can easily pump thickened and treated sludge as well as polymer dosing
- Oil (& gas) – these pumps can withstand drilling mud transfer and recovery, crude oil transfer, cutting transfer, separator feed, main oil line pump, multiphase transfer and more
- Biogas – biomass transfer and digestate feed
What are the advantages of a progressive cavity pump?
There are so many advantages of using a progressive cavity pump. Designed to lift challenging fluids, these pumps can lift substances that other types of pump can’t.
We’ve compiled a list of the most useful advantages of using a progressive cavity pump:
- High accuracy – unique cavity design combined with a flow proportional to the pump speed you can predict the flow and use the machine is metering and dosing applications
- High flow rate – can flow up to 600M³H as a result of the rotary positive displacement design
- Low flowing pulsating rate – low rotary motion RPM limits the flow pulsation which produces a lower amount of acceleration head. Plus, the even wall stators design and long pitch rotor configuration lessens the pulsating rate
- Self Priming – tight construction and high suction capabilities allow self-priming up to 8M paralleled by a low NPSH. As a result, some designs can handle gas slugs of up to 30 minutes long without failing
- Low shear – so even the most challenging fluids can be handled with ease, including resins, oil and water emulsions, without altering the substance consistency. Great for separating oily water because its clever design allows oil droplets to stay unaltered during handling
- Reversible – super handy if there are any blockages, the pump can simply be run in reverse to clear it. A reverse option also makes the pump more versatile than other options because it can be used in other situations like tanker loading and offloading
- Wide fluid handling capabilities – these pumps can handle a huge range of substances including large solids, gas slugs, abrasive materials, viscous liquids and more making it incredibly versatile compared to other pumps in the same field.
When to use a progressive cavity pump
When it comes to deciding which pump is best suited to the job at hand, the first thing to do is understand the substance you’re working with in order to match it with the correct pump size as well as the right operating speed and material. Generally, a progressive cavity pump is best suited to a job that requires a higher pressure than rate of flow.
Other factors to consider are viscosity, temperature and abrasion. The more abrasive the substance you are working with, the bigger pump you will need. A progressive cavity pump will work best with these because they run slower than other pumps. This also goes for higher viscosity fluids. These work much better with a pump that is running slower.