In this video, you will gain an understanding of the CR pump range’s capabilities in demanding industrial applications and learn how it can help meet common industrial challenges like:

High temperature liquids

Challenging liquids

High pressure

Challenging installation conditions

Let's explore the challenges of pumping high-temperature liquids in applications like steam boilers, washing and cleaning, mineral oils, industrial processes, and chemical industries.

High-temperature liquids near boiling point pose significant challenges for centrifugal pumps. The pressure drop at the pump inlet can cause the liquid to boil, generating gas bubbles. As hydraulic pressure increases, these bubbles implode, leading to cavitation, which can damage the pump.

To address this, a special first stage in the pump reduces the initial pressure drop, preventing gas bubble formation and cavitation. The NPSH curves illustrate this pressure drop — lower NPSH means less pressure drop. This pump variant is known as 'Low NPSH'.

In addition to the risk of cavitation, high-temperature liquids can pose a challenge to the shaft seal’s lubrication. Shaft seal faces must always be lubricated to prevent dry-run, which can cause rapid temperature increases, seal damage, and extensive leakage. Normally, the pumped liquid provides a lubricating film, but at high temperatures, steam formation reduces lubrication properties.

The CR pump is available in an 'air-cooled top' variant, which adds an air-cooled chamber to separate the shaft seal chamber from the high-temperature liquid.

This lower temperature in the shaft seal chamber ensures proper lubrication and prevents dry-running, allowing operation from 120°C to 180°C in water.

A small amount of cooled-down liquid keeps the seal chamber filled with liquid at a suitable temperature. For hot thermal oils with low viscosity, the air-cooled top can lower temperatures, enabling oil pumping up to 240°C.

Now let’s look at how to handle challenging liquids in applications such as:

Chemical industries

Pharmaceuticals

Petrochemicals

Distilling plants

Paint industries

Mining

In standard pumping, the pumped liquid lubricates the shaft seal, but often minor leaks occur. This can damage the seal or be problematic if the liquid is undesirable in the environment.

Using a double shaft seal with a sealing chamber that consists of a primary and secondary seal, the CR pump can prevent crystallisation and stickiness and stop abrasive, toxic, or flammable liquids from passing through the shaft seal.

For liquids that crystallise or become sticky, a tandem double seal uses the sealing chamber liquid to flush the primary seal, preventing buildup.

The flushing liquid can circulate in a closed loop or be drained.

For liquids with abrasive particles or toxic/flammable properties, a back-to-back double seal pressurises the sealing chamber liquid higher than the pump pressure. "

This ensures the sealing chamber liquid lubricates the seals, not the pumped liquid. The sealing liquid must be compatible with the pumped liquid and non-toxic. For very toxic or volatile liquids where shaft seals are unsuitable, the hermetically sealed CRN MAGdrive offers a solution. A magnetic-drive system replaces the shaft seal, and an outer drive connects to the motor shaft and an inner drive to the pump shaft, ensuring normal operation. A metal can around the inner drive contains the liquid, preventing evaporation. These solutions allow the CR pump to effectively handle a wide range of difficult liquids, ensuring safe and efficient operation.

Next let’s explore high-pressure applications like filtration, reverse osmosis, boiler feed, washing and cleaning, industrial processes, and water treatment. In these applications, the main challenges are overloaded motor bearings, reduced shaft seal lifetime, and pump height due to the required number of stages.

CR pumps generate a downward axial thrust during operation, …and the more stages in the pump, the greater the downthrust. To handle it, some CR pumps use an angular contact motor bearing, which accommodates axial thrust in one direction. At standstill, inlet pressure causes an upward thrust, which can lift the bearing's rotating part, causing wear over time. To address this, CR pumps are equipped with a bearing flange between the pump and motor, handling axial forces in both directions and ensuring reliability under high inlet pressure. To achieve higher pressure, you can connect pumps in series by using a standard feed pump with a high-pressure pump or add stages or speed up the pump.

In a standard CR pump, pressure builds from bottom to top, exposing the shaft seal to discharge pressure. To prevent seal damage, a special high-pressure pump is available called the CRN-SF pump. By inverting the chamber stack, pressure builds from top to bottom, exposing the shaft seal only to inlet pressure, extending its lifespan.Adding stages increases pressure but also pump height, which can be a space issue. Alternatively, a 9-stage pump, like the CRE 3-9, can deliver the same flow and pressure as a taller pump.

Sometimes the challenge lies not with the liquid inside the pump but in the surroundings where the pump operates. Let's explore some challenging installation applications:

Height limitations

Marine environments

Explosive environments

Negative inlet pressure.

Vertical multistage pumps are naturally tall. If height clearance is an issue, CR pumps can be installed horizontally. For earthquake-prone areas or ship installations, horizontal positioning can also secure CR pumps against bending due to inertia caused by movement.

The  marine environment, whether on ships, rigs, or in harbours, can be a challenging application area as the salty atmosphere can corrode cast iron pump parts. The CRN maritime variant, made entirely of stainless steel, including non-wetted parts, protects against corrosion.

CR pumps can also be installed in environments where risk of gas or dust explosions is likely. For these situations, ATEX and Ex approved CR pump variants ensure safe operation by preventing ignition from sparks or heat. Safety is crucial, especially in delicate installations like food, beverage, or pharmaceutical industries. Here, the cleanability of pump outer parts is essential. The CRN pump can be delivered in a polished variant to ensure surface smoothness, preventing bacteria growth in microscopic grooves.

Certification of compliance is often required when installing pumps in sensitive applications.  At sea, insurance companies may demand certifications, such as Lloyds, Veritas, or China Shipping. In other cases, end-users may require performance documentation or compliance certificates. CR pump variants meet a wide range of certifications available upon request.