When handling aggressive and corrosive fluids, pressure gauges are not simple accessories, but true guardians of the pump’s safety.

By constantly monitoring pressure, they allow for the timely detection of anomalies in the pump functioning such as cavitation, clogging, or overload, preventing catastrophic pump failures.

For this reason, the use of pressure gauges equipped with diaphragm seals made of chemically resistant materials – such as polypropylene (PP) and PVDF – is essential to isolate the instrument from the process fluid, ensuring maximum accuracy and durability over time.

How does a pressure gauge with a diaphragm seal work?

The solutions offered by GemmeCotti are specifically designed to withstand severe operating conditions: these are hermetic systems, pre-filled with a transmission liquid (glycerin), which protect the internal mechanics thanks to the separation diaphragm, ensuring a safe and accurate pressure reading at all times.

Chemical compatibility table

Liquids compatible with PP include: acetic acid 60%, phosphoric acid, seawater, ferric chloride, citric acid, ethyl alcohol, liquid ammonia, sodium hydroxide (caustic soda, at low concentrations and temperatures), detergents, sodium bisulfite, and many others.

Liquids compatible with PVDF include: acetic acid 20%, ethyl alcohol, zinc chloride, formaldehyde, hydrochloric acid, nitric acid (up to certain concentrations), hydrogen peroxide, sulfuric acid 98%, methyl alcohol, and potassium hydroxide.

You can verify the correct combinations directly in our chemical compatibility table.

Measuring ranges and available configurations:

GemmeCotti diaphragm pressure gauges are designed to cover the main pressure monitoring needs in industrial pumping circuits. The range is structured into four standard configurations based on the required pressure scale:

• Pressure gauge with scale 0 – 2.5 bar
• Pressure gauge with scale 0 – 6 bar
• Pressure gauge with scale 0 – 10 bar
• Pressure gauge with scale 0 – 16 bar

*Also available in double scale bar/psi.

Each of these measuring ranges (from 2.5 to 16 bar) can be paired indistinctly with a PP or PVDF fluid seal. This flexibility allows engineers and plant managers to configure the perfect combination between pressure range and chemical compatibility, accurately responding to every specific application need.

Diaphragm seal pressure gauges and all other recommended accessories are available for purchase directly on our shop.

Do you want to secure your chemical pumping system? Contact the GemmeCotti technical department: info@gemmecotti.com

In the chemical pumping sector, choosing the correct technology is fundamental to guarantee safety, efficiency, and operational continuity. Series HTT regenerative magnetic drive turbine pumps by GemmeCotti are the solution for those who need to handle highly corrosive and clean liquids with maximum reliability.

How does a magnetic drive turbine pump work?

HTT pumps combine the advantages of the regenerative turbine with the innovation of the magnetic drive. Unlike traditional pumps, the transmission of motion occurs through magnetic forces, completely eliminating the use of mechanical seals.

The main advantages of the HTT series turbine pumps include:

• Zero leaks: The absence of mechanical seals drastically reduces the risk of dangerous emissions into the environment and maintenance costs.
• Maximum safety: Ideal for fluids that must not come into contact with the environment.
• Cavitation resistance: Thanks to their design, these pumps can pump liquids with a gas presence of up to 20%.
• Reversibility: One of the distinctive features of the HTT series is its complete reversibility.

Designing systems for corrosive liquids requires extreme flexibility, and HTT pumps allow the configuration to be adapted to real operational needs.

– Flow reversal: It is possible to reverse the suction and delivery ports (in & out) simply by reversing the motor’s direction of rotation.

What are the best materials for pumping highly corrosive liquids?

HTT pumps are made of molded thermoplastic materials (PP and PVDF), chosen for their excellent chemical compatibility.

• PP (Polypropylene): Ideal for a wide range of chemicals, it supports temperatures up to 60-70°C.
• PVDF: Indicated for heavier-duty applications, with a thermal resistance up to 90°C.
• Internal components: The static shaft is made of 99.7% pure alumina, while the bushings are in graphite-filled PTFE to guarantee high chemical resistance.

Performance and technical data of the HTT range:

The HTT range offers versatile performance for different industrial needs:

• Maximum flow rate: Up to 9 m³/h.
• Maximum head: Up to 48 mcl.
• Maximum viscosity: Up to 45 cPs.
• Nominal pressure: PN 6 at 20°C.

Scrubbers play a vital role in implementing emission control systems in compliance with ESG regulations, and their efficiency depends almost entirely on the performance of the installed chemical pumps.

In this guide, we will explain how a wet scrubber works and outline the challenges faced by the chemical pumps used in air pollution control systems.

What is a wet scrubber and how does it work?

A wet scrubber is a system designed to remove particulate matter and harmful gases from industrial exhaust streams. The process involves a “washing” phase in which the gas to be purified comes into contact with a liquid — usually water or a water-based chemical solution — that absorbs or neutralizes pollutants. 

The working cycle:

1. Gas intake: the contaminated air enters the wet scrubber chamber from the bottom.
2. Liquid injection: centrifugal pumps move the washing liquid to the upper part of the tower, where it is sprayed downwards.
3. Absorption: as the gas rises, it meets the liquid droplets. Pollutants are transferred from the air to the fluid.
4. Recirculation: the “dirty” liquid is collected in a tank and recirculated by the pump into the system, or sent for treatment.

Common fluids and industrial applications

Wet scrubbers are versatile and used in various sectors to manage aggressive chemicals:

• Neutralization of acid fumes: use of caustic soda or lime to remove hydrogen sulfide, hydrochloric acid, or sulfur dioxide.
• Gas depuration: use of monoethanolamine (MEA) to remove carbon dioxide.
• Particulate removal: simple water-based washing for dust control.

Why choose GemmeCotti chemical pumps for air treatment? 

Our pumps are specifically designed to meet the demanding requirements of the air treatment and flue gas cleaning industries.

Choosing GemmeCotti pumps means investing in long-term reliability: thanks to the use of corrosion-resistant thermoplastic materials such as Polypropylene (PP) and PVDF, we guarantee superior chemical resistance compared to traditional metals, drastically reducing maintenance costs and plant downtime.

HTM PP/PVDF SERIES MAGNETIC DRIVE HORIZONTAL CENTRIFUGAL PUMPS 

HTM PP/PVDF magnetic drive pumps for acids feature a special sealless design that ensures the total absence of leakage and emissions into the envir

onment.

Technical data:

 – Flow rate up to 130 m³/h 

– Head up to 48 mlc

HCO SERIES MECHANICAL SEAL HORIZONTAL CENTRIFUGAL PUMPS 

HCO mechanical seal centrifugal pumps are the most suitable solution for applications requiring the pumping of liquids with suspended solids. Their semi-open impeller design allows for the handling of dirty fluids (non-abrasive solids – max. 5% – max. size 3 mm).

Technical data: 

– Flow rate up to 130 m³/h 

– Head up to 48 mlc

VERTICAL CENTRIFUGAL PUMPS 

Vertical centrifugal pumps are suitable for applications requiring the pump column to be immersed in the liquid (tanks, reservoirs, sumps, etc.).

HV SERIES MONOBLOCK VERTICAL CENTRIFUGAL PUMPS 

HV vertical pumps are available with different column lengths (500 – 800 – 1000 mm).

Technical data: 

– Flow rate up to 40 m³/h 

– Head up to 22 mlc

HVL SERIES VERTICAL CENTRIFUGAL PUMPS WITH BRACKET 

HVL vertical pumps are available with various column lengths, from 500 mm up to 2000 mm.

Technical data: 

– Flow rate up to 130 m³/h 

– Head up to 48 mlc

Selecting the right pump is essential to ensure process safety.
Contact us at info@gemmecotti.com for a personalized consultation: we will help you identify the most suitable model and materials for your specific operating requirements.

Data centers are facing an increasingly complex challenge: cooling microprocessors of growing power and high density. With the rise of artificial intelligence, cloud computing, and high-performance computing, traditional air-cooling systems are no longer sufficient. For this reason, more and more data centers are being equipped with liquid cooling systems, which allow heat to be dissipated directly from the source: the microprocessors.

In these systems, circulation pumps play a fundamental role, as they ensure the constant flow of coolant within the cooling circuits.

GemmeCotti’s magnetic drive centrifugal pumps, available in PP, PVDF, and AISI 316 stainless steel, represent a reliable and efficient solution for various data center cooling technologies.

What is the purpose of a cooling pump in a data center?

The primary function of the pump is to manage the recirculation of the cooling medium (liquid) throughout the entire circuit. This process is vital for dissipating the heat generated by electronic equipment and servers which, in the absence of constant flow, would suffer critical overheating.

A thermally uncontrolled environment leads to serious risks, including:

• Hardware failure and reduction of component lifespan.
• Data loss and service interruptions (downtime).
• Increased energy costs, as the entire system must work with greater intensity to compensate for heat accumulation.

How pumps work in data center cooling systems

In cooling systems, pumps ensure the continuous flow of coolant within the cooling circuit. The liquid removes the heat generated by the microprocessors and carries it to a heat exchanger for dissipation.

The fluid used can be water, water-glycol mixtures, or specific dielectric fluids for electronic cooling. Regardless of the liquid type, the pumps must guarantee reliable and continuous operation, avoiding leaks and minimizing maintenance interventions.

GemmeCotti magnetic drive pumps are particularly suitable for these applications because, having no mechanical seal, they guarantee an airtight seal of the hydraulic part, eliminating the risk of unwanted fluid leaks into the system.

GemmeCotti magnetic pumps: reliability and operational safety

Magnetic drive pumps represent a particularly suitable solution for data center cooling systems, where reliability, operational safety, and continuity of operation are fundamental elements.

• Elimination of Leaks: Unlike traditional pumps with mechanical seals, magnetic pumps eliminate the risk of fluid leaks thanks to the transmission of movement via magnetic coupling.
• Reduced Maintenance: The absence of mechanical seals also reduces maintenance interventions and increases system reliability—essential characteristics for critical infrastructures like data centers that must operate continuously.
• Industrial Design: GemmeCotti HTM magnetic drive centrifugal pumps are designed specifically for industrial applications requiring safety, chemical resistance, and continuous operation. They can be integrated into various industrial cooling systems and liquid cooling circuits.

Solutions and materials for every need

The HTM range is available in different materials to adapt to the various fluids used in data center cooling circuits:

• HTM Pumps in PP and PVDF: These offer high chemical resistance and are particularly indicated when using aggressive fluids or specific refrigerants. The thermoplastic construction guarantees excellent corrosion resistance and a long operational life.
• 

• HTM Pumps in AISI 316 Stainless Steel: These represent a robust and reliable solution for applications requiring greater mechanical resistance and compatibility with different process fluids.

Technical Performance

To meet every need, the HTM PP/PVDF series offers performance at both 50 Hz and 60 Hz:

• Max Flow Rate: up to 130 m³/h / 528 USGPM.
• Max Head: up to 48 m / 148 ft.
• Temperature Range: PP max 60°C (158°F) – PVDF max 90°C (194°F).
• Max Viscosity: 200 cSt.
• Nominal Pressure: NP 6 bar (90 PSI) at 20°C (68°F).

Thanks to magnetic drive technology, high reliability, and the possibility to choose between different material configurations, GemmeCotti HTM pumps represent an effective solution for data center cooling systems. These components guarantee the necessary precision in fluid handling, absence of vibrations, and total safety against refrigerant leaks.

For more information on GemmeCotti solutions for your cooling systems, contact our technical team at info@gemmecotti.com

In the field of pumping corrosive and hazardous liquids, safety is not an option but an absolute necessity. Chemical fluid leaks can cause environmental damage, risks to operators, and costly downtime. The GemmeCotti HTM series was developed to meet these challenges, offering a zero-leak solution thanks to its magnetic drive design.

In this guide, we will explore how it works, its advantages, and how to choose the ideal configuration of HTM centrifugal pumps for various industrial processes.

What is magnetic drive and how does it work?

Unlike traditional pumps with mechanical seals, GemmeCotti HTM series pumps use an innovative design without a mechanical seal. In a magnetic drive pump, there are two magnetic couplings: the outer magnet, mounted on the motor shaft, and the inner magnet, which allows the impeller to rotate and move the fluid.

The two magnetic semicouplings are separated by a containment shell and never come into contact with each other; the inner magnet rotates exclusively through the magnetic field action. The liquid therefore always remains hermetically sealed within the hydraulic part of the pump. This design ensures maximum safety, greater reliability, and excellent efficiency, even in the most demanding applications.

For an even more detailed visual explanation, an explanatory video is available on YouTube showing the operating principle in action.

What are the advantages of HTM magnetic drive pumps?

Choosing a GemmeCotti magnetic drive pump means investing in safety, efficiency, and quality.

The advantages that distinguish these acid pumps are:

• No leaks or emissions: ideal for handling hazardous chemicals. The liquid always remains hermetically sealed inside the hydraulic section of the pump.
• Reduced maintenance: fewer wear components (such as mechanical seals) means lower operating costs, no plant downtime, and long-term savings.
• No motor/pump alignment required: the compact design simplifies installation and reduces vibrations.
• Maximum reliability: solid construction made of chemically resistant materials (PP, PVDF, AISI 316). HTM series centrifugal pumps are the ideal solution for long-lasting performance, even in heavy-duty conditions.
• Long-term savings: pumps designed to last for decades.
• High-torque magnetic coupling: these pumps are designed to ensure high torque of magnetic couplings.

Performance and materials: a tailor-made solution for every need

Every industrial application has different requirements. For this reason, the HTM range, from size 4 to 100, offers wide operational flexibility.

Technical specifications

• Flow rate: From 0.5 to 130 m³/h (2–528 USGPM)
• Head: Up to 48 meters (148 ft)

Chemical compatibility

The choice of material in contact with the liquid is essential for pump durability:

• PP (Polypropylene): Excellent for many liquids such as phosphoric acid, ammonia, and caustic soda.
• PVDF (Polyvinylidene Fluoride): Ideal for aggressive acids such as sulfuric acid, hydrofluoric acid, sodium hypochlorite, and many others.
• AISI 316: Stainless steel suitable for fluids such as diesel, acetone, ethyl alcohol, hydraulic oils, and many others.

In addition to thermoplastic versions, HTM pumps can also be manufactured in AISI 316 stainless steel. This configuration is particularly suitable for demanding industrial applications requiring high mechanical and thermal resistance. The robustness of steel, combined with the safety of magnetic drive technology, makes these pumps the ideal choice for transferring hydrocarbons and solvents with total absence of leaks.

Technical specifications (AISI 316 Version)

• Flow rate: From 0.8 to 32 m³/h (3–175 USGPM)
• Head: Up to 24 meters (110 ft)

Discover the complete range and specifications of HTM magnetic centrifugal pumps in AISI 316.

For explosive environments, ATEX Zone 1 and 2 versions are also available (Models EM-C PP/PVDF and EM-C AISI 316).

The GemmeCotti team is available to help customers select the pump best suited to their application.

Contact us at info@gemmecotti.com for a free quotation.

Mechanical seal pumps with a semi-open impeller, such as the HCO type, are generally used for pumping acids and hazardous liquids when solids are present in the fluid, making it impossible to use magnetic drive pumps.
Their semi-open impeller design allows the safe transfer of corrosive liquids even when particulate matter is present.

The mechanical seal in these pumps consists of a stationary ring and a rotating ring mounted on the pump shaft, which is directly coupled to the motor shaft. The two contact surfaces must be lubricated, and this occurs through the pumped liquid itself.

Choosing the right mechanical seal for a centrifugal pump is essential to ensure safety, reliability, and long operational life, especially when pumping corrosive and aggressive liquids.

The GemmeCotti HCO centrifugal pump series, made of PP or PVDF, is available with different mechanical seal configurations designed to meet a wide range of industrial applications and operating conditions.

What seal types are available on HCO pumps?

The GemmeCotti HCO centrifugal pump range offers several sealing solutions, selected according to pump size, operating conditions, and the type of processed fluid. The main seal types available are:

• Elastomer Lip Seal – used on models HCO 95-10. This is a very simple and cost-effective solution for less demanding chemical applications with reduced performance.
• Single internal mechanical seal with PTFE bellows – adopted on models HCO 110-170. It combines high chemical resistance with excellent reliability thanks to PTFE bellows and the materials used for the seal faces (Standard: SiC / Ceramic; available on request: Graphite / Ceramic).

• Single internal mechanical seal with PTFE bellows, available on models HCO 180-200. Generally supplied in SiC / Ceramic, ideal for pumping acids and corrosive liquids under standard operating conditions with a maximum solids content of 3% and particle sizes not exceeding 5 mm. It allows high flow rates up to 130 m³/h.
• 

• Double back-to-back mechanical seal – available on models HCO 180-200 for more critical applications. This seal guarantees the highest safety level thanks to a dual sealing system with barrier fluid. It is recommended for dangerous or aggressive fluids, maintaining the same high capacity (up to 130 m³/h) even under severe operating conditions.

🔗 Discover all HCO versions and available seals

What is a single mechanical seal and when should it be used?

A single mechanical seal consists of one sealing interface between the rotating shaft and the pump casing. It is the most common solution in centrifugal pumps for standard chemical applications.

In GemmeCotti HCO pumps from size 110 to 170, the single seal can be supplied in different materials depending on the pumped fluid. The standard version includes stationary and rotating rings in SiC / Al₂O₃, while an alternative stationary graphite ring is available on request.

On models HCO 180 and HCO 200, the seal rings are made of Silicon Carbide / Ceramic, ensuring good wear resistance, operational reliability, and an optimal balance between performance and cost.

Single mechanical seals are particularly suitable when the pumped fluid is not highly hazardous and when operating conditions (pressure, temperature, chemical composition) remain within standard parameters. In such cases, they provide high performance with a simple, economical, and maintenance-friendly design.

Advantages of a single mechanical seal

• Simple and compact design
• Lower initial investment compared to double seals
• Reduced maintenance needs thanks to fewer components
• Reliable pumping of acids and corrosive liquids under standard conditions

Typical applications

• Transfer of chemicals in industrial plants
• Water and chemical wastewater treatment
• Standard chemical processes where extra safety is not required

When handling highly dangerous, abrasive fluids or particularly critical applications, a double mechanical seal is recommended for higher safety.

What is a double mechanical seal and why is it suitable for critical applications?

A double back-to-back mechanical seal consists of two seal faces mounted opposite each other inside the seal chamber, with an interposed barrier fluid that ensures proper lubrication and heat dissipation.

This configuration offers a higher safety level and is the preferred solution for heavy-duty and critical applications where a single seal is not sufficient to contain the pumped fluid.

To ensure correct operation, an external flushing system must be provided to supply and circulate the barrier fluid at the required pressure.

On GemmeCotti HCO centrifugal pumps, the back-to-back double seal is particularly suitable for pumping dangerous, corrosive fluids or liquids containing suspended solids up to 5% with particle sizes under 5 mm, as well as abrasive particles, while maintaining high performance and long-term reliability.

Advantages of a double mechanical seal

• Greater safety: significantly reduced risk of leakage, especially with hazardous or toxic fluids
• Environmental protection: better containment and prevention of contamination
• Longer service life: two seals reduce stress on each face, extending durability and lowering maintenance frequency
• Reliability in severe conditions: ideal for abrasive fluids, high temperatures, and demanding operating conditions

The choice depends on the liquid type, operating conditions, temperature, and plant safety requirements.

What materials are used in HCO centrifugal pumps with a mechanical seal?

All GemmeCotti HCO centrifugal pumps are made of high-performance thermoplastics, ideal for the chemical industry:

• PP (Polypropylene) – excellent chemical resistance, max temperature about 70 °C
• PVDF (Polyvinylidene Fluoride) – superior chemical resistance, max temperature about 90 °C

These materials ensure maximum corrosion resistance, long service life, and reliability.

How to choose the most suitable mechanical seal for an HCO pump

When selecting the right mechanical seal, it is important to evaluate:

• Chemical characteristics of the pumped fluid
• Hazard and toxicity level
• Operating temperature and pressure
• Required safety level
• Maintenance strategy of the plant

For standard chemical services, a single mechanical seal is often sufficient.
For dangerous or critical applications, a double mechanical seal is strongly recommended.

Is the pumped liquid clean? Magnetic drive pumps are the ideal solution to guarantee zero leakage and emissions into the environment, with extremely low maintenance. Learn more about the advantages of magnetic drive technology.

 For technical support and advice, contact the GemmeCotti team: info@gemmecotti.com