TLDR
- The correct coating improves the performance of the centrifugal pump, maintains it throughout its lifetime, and reduces maintenance costs.
- The main problem is the poor compatibility of the coating with the pumped liquid, for example, aggressive acids and bases, oil or seawater.
- The choice of coating takes into account five factors: chemical compatibility, maximum temperature, abrasion resistance, mechanical stress, and protection from the external environment.
- CDR produces in Italy two families of lined pumps: a mechanical seal (UCL/UCL-B, CCL/CCL-B) and a magnetic drive (ETN, UTN-BL/UTN-L).
- The available coating materials are PP, PVDF, PFA and ETFE, depending on the pump model chosen.
Index
What are the advantages of clad pumps?
Maintenance, efficiency, durability: why use lined pumps and the importance of the most suitable coating material.
The factors that negatively contribute to the lifespan and efficiency of a centrifugal pump are several. After improper use by the operator and poor maintenance, the quality of the lining plays a decisive role.
Choosing the correct coating
The main problem is due to poor compatibility with the fluids being handled. For example, pumping oil, aggressive bases/acids, seawater, along with particular weather or temperature conditions, can quickly damage an incompatible coating.
Chemically compatible and mechanically resistant coatings are needed to withstand these adverse factors and to ensure an acceptable service life for the machinery. The coatings will therefore need to be selected considering:
- Chemical compatibility: To prevent erosion from chemicals (and.g., acids/bases, solvents, etc.), great care must be taken in selecting the material for the centrifugal pump. While the most common macro families are essentially divided into metal and plastic, there are many compositions and subtypes that must be carefully chosen based on their compatibility and resistance properties.;
- Maximum temperature: Extreme conditions, whether natural or processing-induced, can trigger or accelerate chemical attack and wear on metal parts.;
- Abrasion resistance There are liquids containing dust or particulates that, under certain operating conditions, can cause material removal and erode the mechanical parts of the pump. Resistant metallic coatings or special protective plastic materials provide a barrier that increases abrasion resistance.;
- Mechanical stresses The metal or coated parts must also be selected considering the mechanical limitations of the material; they must withstand the intense pressure and stresses (and.g., torque, torsion, etc.) that could compromise the equipment's lifespan.;
- Protection from the external environment: In addition to the internal protection of the pump against the process fluid, the aggressiveness of the external environment must also be considered. In particular industrial contexts, it is necessary to protect the external surface of the pump, if located, for example, in the presence of corrosive vapors, high salinity environments, etc. Rust is typically one of the most common factors of corrosion. The external coating is therefore selected by identifying the correct protective paint and the most suitable thickness.
It has been shown that the use of the correct line not only improves pump performance but also maintains it throughout its lifespan with minimal maintenance. The use of lined pumps therefore helps to increase and maintain good hydraulic efficiency for longer, as well as reducing maintenance costs.
CDR lined pumps
CDR produces and markets two families of lined centrifugal pumps made in Italy, both with mechanical seals and magnetic drives. The mechanical seal models, effective even with liquids containing a moderate presence of particulates, include:
- UCL/UCL-B: Single-stage, mechanically sealed, plastic and fluoroplastic-lined process centrifugal pumps. Available materials: PP (polypropylene), PVDF (polyvinylidene fluoride), PFA (perfluoroalkoxy).
- CCL/CCL-B: Single-stage, close-coupled, mechanically sealed process centrifugal pumps with plastic lining. Available materials: PP (polypropylene), Baseplate execution (CCL) and close-coupled (CCL-B).
For magnetic drive pumps, which ensure that the pumped liquid is completely contained, CDR Pompe offers the following range:
- ETN Single-stage magnetic drive process centrifugal pumps lined with plastic and fluoropolymer materials. Available materials: PP (polypropylene) and ETFE (Ethylene Tetrafluoroethylene). These are low-duty pumps used primarily for tank unloading and discharge services.
- UTN-BL/UTN-L: Single-stage magnetic drive centrifugal process pumps with plastic and fluoroplastic lining. Available materials: PP (polypropylene), PVDF (polyvinylidene fluoride), PFA (perfluoroalkoxy).
These are heavy-duty pumps primarily used in continuous service and are available in both monobloc and base-mounted versions. If you are interested in CDR lined centrifugal pumps, please contact our sales office for more information.
Frequently Asked Questions
What are the advantages of coated centrifugal pumps compared to uncoated ones?
They lined pumps maintain hydraulic efficiency longer and require minimal maintenance. The correct coating protects metal parts from corrosion, erosion, and abrasion caused by the pumped liquid. This extends the machine’s lifespan throughout its entire life cycle and reduces maintenance costs.
How do you choose the right coating material for a pump that moves aggressive chemical fluids?
The coating is chosen by considering five factors: chemical compatibility with acids, bases and solvents, maximum temperature, resistance to particle abrasion, mechanical stresses such as pressure and torque, and protection from the external environment. Inadequate compatibility with the pumped liquid is the main cause of rapid deterioration of the coating.
What liquids and conditions can damage the casing of a centrifugal pump?
Oil, bases and aggressive acids and seawater can quickly damage a poorly compatible coating, especially with high temperatures or particular weather conditions. Even liquids containing dust or particulate matter can remove material and erode the mechanical parts. Outdoors, corrosive vapours and high salinity favor rust.
Which ones lined pumps are mechanical seal produced CDR Pompe and with which materials?
CDR Pompe The UCL/UCL-B series of single-stage pumps are produced in Italy mechanical seal. The UCL/UCL-B are coated in PP, PVDF or PFA. The CCL/CCL-B are coated in PP and are available on a (CCL) or monobloc (CCL-B) basis. They are also suitable for liquids with a moderate particle content.
What is the difference between the lined pumps magnetic drive ETN and UTN-BL/UTN-L?
ETN are low-duty single-stage pumps magnetic drive, coated in PP or ETFE and used primarily for tank discharge and emptying. UTN-BL/UTN-L are heavy-duty, coated in PP, PVDF or PFA, suitable for continuous service and available in a monobloc configuration or on a base. Both contain the pumped liquid completely.
How is the external surface of a pump protected in corrosive or highly saline environments?
The external surface is protected with a protective paint chosen correctly and with an appropriate thickness. This is especially necessary where there are corrosive vapors or high salinity, because rust is one of the most common factors of corrosion. This protection is added to the internal protection against the process fluid.