Process Pumps: Choosing the Right Solution for the Chemical Industry

Summary

This article analyzes how the selection of process pumps directly influences the stability and safety of chemical plants. Often, inefficiencies and production stoppages do not result from macroscopic failures, but from an inadequate pump choice for actual operating conditions.

The article examines the main critical issues related to the handling of corrosive, viscous, or high-pressure fluids, emphasizing how a superficial approach can trigger phenomena such as cavitation, premature wear of components, and product contamination. It then defines the essential technical parameters for accurate selection, including a detailed analysis of the fluid, precise calculation of flow rate and head, and the crucial importance of material compatibility.

Particular attention is paid to magnetically driven pumps, a technology that, by eliminating the need for mechanical seals, reduces the risk of fugitive emissions and ensures greater protection for operators and the environment. Ultimately, the article offers a methodological guide for balancing hydraulic performance with the need to reduce maintenance interventions and ensure production continuity in severe operating scenarios.

Process Pumps: Choosing the Right Solution for the Chemical Industry

Many problems related to fluid handling in the chemical sector arise at points in the system that, at first glance, may seem minor. A temperature fluctuation that alters the fluid’s viscosity, a seal that wears out faster than expected, or even the slightest chemical incompatibility between materials are all factors that can lead to corrosion of internal surfaces and compromise the stability of the production line. Process pumps used in the chemical industry actually operate under very aggressive conditions and therefore must be designed to ensure safety, production continuity, and process control.

Fluids such as concentrated acids, solvents, toxic solutions, high-temperature substances, or liquids containing solid particles require devices designed to maintain constant performance under continuous stress. Especially in chemical processing, furthermore, the margin for error is extremely low: A leak, a drop in flow rate, or an anomaly in fluid circulation can be sufficient to cause production stoppages, environmental contamination, and dangers to worker safety.

For this reason, it is crucial to choose the process pumps corrected for the specific use. It is not enough to evaluate the required capacity or system size; it is necessary to analyze in detail the fluid behavior, thermal conditions, material compatibility, and the most suitable technologies for the specific application.

The right choice is to consider installing magnetic drive centrifugal pumps, available in the catalog of CDR Pompe. Thanks to the absence of mechanical seals and the use of fluoroplastic materials, they guarantee extremely high safety and strong resistance to corrosion.

Critical issues of fluid handling in the chemical industry

The chemical industry uses fluids with very different properties. Some products contain highly corrosive substances (strong acids and bases), others work at temperature increase, or they present particular density and viscosity or easily variable. In numerous production lines, solid particles or abrasive residues are also found suspended in the fluid, which accelerate internal pump wear if they are not adequately designed.

These difficulties are compounded by further factors:

• Continuous and heavy-duty operation of the plants: 24/7 operating cycles that minimize time windows for preventive maintenance;

• High pressure stresses need to overcome high process backpressures or to operate in high static pressure systems;

• Classification of Areas (ATEX Zones): operation in potentially explosive atmospheres due to the presence of flammable gases, vapors, or combustible dusts;

• Absolute necessity to avoid leaks and fugitive emissions: imperative constraint to prevent the leakage of ecotoxic, carcinogenic, or lethal fluids;

• Production processes highly sensitive to flow rate variations: Chemical reactions whose yield strictly depends on the millimeter-scale constancy of the injected flow.

In this scenario, process pumps must ensure Hydraulic stability, maintenance of the working point, and high operational accuracy also following prolonged and heavy work cycles.

Problems caused by unsuitable process pumps

The installation of a process pump whose sizing or material selection disregards the actual and overall operating conditions can, over time, lead to serious problems and failures throughout the entire system.

Materials incompatible with the treated fluid tend to deteriorate rapidly and cause degradation, residue, and breakage, Mechanical seals can be damaged when subjected to strong chemical stresses, while Corrosion and abrasion they remove material from impellers and pump casings, causing a rapid decay of hydraulic efficiency.

Among the most frequent problems are:

• Cavitation: local fluid vaporization (due to incorrect calculation of NPSH (available), resulting in violent collapse of microbubbles and mechanical destruction of metallic surfaces;

• Structural fluid loss and emissions: Failure of containment barriers with release of hazardous substances into the work environment;

• Product contamination: fluid infiltration or release of particles from internal degradation that alter the purity of the batches;

• Damage to internal parts breakage of shafts, impellers, bushings, and bearings caused by abnormal vibrations or mechanical overloads;

• Exponential increase in maintenance interventions: operational cost drift and shortening of the spare parts lifecycle;

• Sudden production line stoppages unplanned interruption of the value chain, with substantial economic losses and complex remediation procedures.

In the chemical sector, even a minimal leak can lead to significant safety and environmental management issues. For this reason, the process pumps they must be designed according to the actual plant conditions.

How to choose the correct process pumps

The choice of process pumps goes through the analysis of all these potential problems and all the rigid parameters required by the chemical industry. Each application requires specific evaluations related to the fluid, the required performance, and the working conditions.

Required flow rate and head

Among the first elements to consider are flow rate and head.

Flow rate defines the volume of fluid the machine must transfer per unit of time, while head indicates the net energy, expressed in meters of liquid column, that the pump must impart to the fluid to overcome the height difference between the tanks, the resistances that form inside the pump, and the head losses (distributed and localized) generated by the friction of the fluid along the piping and equipment.

Incorrect sizing can, for example, cause high consumption, premature wear, and unstable operation from the very first use. An oversized pump operates far from its point of maximum efficiency, while an undersized solution risks not ensuring continuity of the production process, overheating the fluid and risking operation under stall conditions.

Analysis of the pumped fluid

The fluid characteristics are the first factor to consider when selecting a pump for your chemical system.

To identify the process pumps more suitable ones need to be evaluated:

• Detailed chemical composition: identification of the chemical specifications of the fluid to be pumped;

• Corrosivity Level: pH assessment and presence of oxidizing agents or chlorides;

• Fluid viscosity critical parameter that modifies internal friction losses in the pump, requiring correction factors or a shift towards positive displacement technologies instead of centrifugal ones;

• Density and specific gravity determinants for calculating the required hydraulic power at the shaft and for correct engine sizing;

• Presence of suspended solids analysis of the hardness and percentage concentration of stable or colloidal particles;

• Operating temperature: key element for verification of NPSH available with respect to the fluid;

• Behavior during pumping: fundamental for predicting viscosity variations within the machine.

Viscous liquids, for example, require different solutions than light, low-density fluids. Similarly, the presence of solid particles can increase internal wear and reduce component life, requiring specially designed pumping solutions to manage these situations.

Chemical compatibility also plays a central role: In fact, some substances rapidly attack metals, gaskets, and internal surfaces if the materials have not been chosen correctly.

Working temperature and pressure

Elevated temperatures and high pressures subject pumps to significant mechanical and thermal stresses that must be considered when selecting a process pump.

When the fluid operates at high temperatures, materials and components must maintain structural stability even in the presence of continuous thermal expansions. Gaskets and seals, in particular, must retain their elastic and containment characteristics without deformation or leakage.

Similarly, when pressures are high, robust pumps designed to extremely strict standards, like those in the CDR catalog, are needed. It is necessary to use solid structures that withstand time without deforming, so as to prevent internal components from touching or being damaged during movement. For this reason, pumps for the chemical industry are chosen with ample safety margins, taking into account the harsh working conditions they will be subjected to.

Material Compatibility: A Decisive Factor for Process Pumps

In the chemical sector, the material selection fluids duration, safety, and reliability of pumps. The material must be selected during the design phase and should be chosen based on the fluid to be moved, according to its characteristics and corrosiveness.

Depending on the application, the following are used:

• Stainless steels: (e.g., AISI 316L) to ensure excellent mechanical resistance and protection against general corrosion;

• Advanced fluoropolymers: (e.g., PTFE, PFA, PVDF) used both as internal lining (lining) as solid structural components for chemically aggressive fluids where metals do not offer sufficient inertia;

• Anti-corrosion and wear-resistant coatings: ceramic or metal carbide depositions via thermal processes to increase surface hardness;

• Structural technopolymer materials (e.g., PP, PE-HD) used for auxiliary or light chemical services at moderate temperatures.

Each fluid reacts differently to the materials it comes into contact with, and as a result, inadequate compatibility accelerates corrosion, wear, and deterioration of internal surfaces.

The process pumps they must therefore be constructed with materials capable of resisting the substances treated and the plant's conditions. A correct choice allows for limiting premature replacements, production downtime, and extraordinary interventions.

In many chemical applications, moreover, compliance with safety regulations requires components designed to very stringent standards.

Magnetic drive pumps: leakage control and increased safety

In the chemical sector, the magnetic drive pumps are used mainly in applications involving toxic, corrosive, or dangerous fluids. This technology eliminates the traditional mechanical seal thanks to a permanent magnet system that transfers rotary motion magnetically, without any direct mechanical connection between the motor shaft and the pumping part.

The absence of a seal drastically reduces the risk of leaks, creating a vacuum that ensures a very high level of safety, a fundamental aspect when there is a risk of spills that could contaminate the environment and create dangers for workers.

For this reason many process pumps dedicate to the chemical industry use these magnetic drive systems, particularly suitable in cases where fluid containment requires high levels of safety.

Among the main advantages of this solution:

• Reducing losses and emissions Hermetic and static confinement of the process fluid;

• Reduced overall wear and elimination of mechanical seals: absence of parts most subject to wear;

• Minimal maintenance;

• Greater protection for worker health and the environment: active prevention of the risk of contact with harmful or lethal substances;

• Better management of aggressive fluids: absence of external contamination of the process fluid.

Magnetic drive pumps are used for transferring acids, solvents, and highly hazardous substances where reliability and fluid containment are of paramount importance.

CDR Process Pumps for the Chemical Industry

The chemical sector is one of the main areas of application for CDR process pumps. For handling hazardous, corrosive, and toxic liquids, our catalog features a wide selection of “lined” pumps—that is, pumps lined with thermoplastic or elastomeric materials—manufactured using “transfer molding. 

These pumps ensure extremely high chemical resistance to liquids such as strong acids, bases, and solvents, preventing both corrosion and product deterioration, extending its useful life, and reducing the risk of problems and the need for ordinary maintenance.

Specifically developed as acid pumps, and therefore perfect for the chemical industry, we find, for example:

• ETV EVOmagnetic drive pump lined, with an internal lining of high chemical resistance plastic materials, such as ETFE or PP. In accordance with the Sub-ISO 2858 standard, it is ideal for handling solutions such as sodium hypochlorite.
• XTN-BL: PFA-lined magnetic drive pump, with Open rotating and diamond bushings, it is part of CDR's X Series and is designed for the handling of substances such as, for example, hydrofluoric acid.
• UTS EVO: used in chemical environments such as reactors, distillation columns, and heat exchangers, it is ideal for maintaining constant temperatures (even high ones) and for ensuring controlled reactions and products that meet specifications. Ideal, for example, for handling’diathermy oil.
• DTN-L: ideale per il pompaggio di acido solforico e altri fluidi aggressivi,  possono essere utilizzate in continuità nei processi chimici più impegnativi

Choosing process pumps based on the application

Nel settore chimico, ogni impianto presenta caratteristiche specifiche che richiedono valutazioni tecniche precise. Fluido trattato, temperatura, pressione, Material compatibility e tecnologia di pompaggio devono essere analizzati insieme per individuare la soluzione più adatta.

The process pumps utilizzate in questi ambienti devono garantire continuità, sicurezza e resistenza anche in presenza di condizioni particolarmente severe.

Una selezione corretta consente di ridurre guasti, contenere i costi manutentivi e mantenere stabile il funzionamento dell’impianto nel tempo. Per questo motivo, affidarsi a soluzioni progettate specificamente per applicazioni chimiche permette di ottenere maggiore affidabilità e migliore controllo dell’intero processo produttivo.

Contatta CDR Pompe per una consulenza e per conoscere tutti i servizi di assistenza, installazione e maintenance dedicati alle pompe do processo.