The Alfa Laval CB series covers three distinct variant families, each engineered for a different pressure, temperature, and certification envelope. Choosing the right variant early in the specification process avoids costly rework and confirms the unit meets the regulatory framework of the installation site.

Standard CB and CBH high-pressure models

Standard CB models such as the CB40 and CB200 address the broadest set of industrial and HVAC duties. The CB40 handles a maximum throughput of 8.8 m³/h with plates as few as 4 and as many as 150, making it well suited to smaller commercial heating loops or oil cooling circuits. The CB200 scales up: its 0.51 litre channel volume, maximum particle tolerance of 1.8 mm, and parallel flow arrangement support higher-capacity industrial processes.

CBH variants, such as the CBH200, share the same plate geometry but are rated for specific pressure requirements. High-temperature heat pump installations documented by Alfa Laval utilize heat exchangers as condensers and subcoolers at pressures up to 28 bar within large-scale district energy systems. This pressure capability makes CBH models a common choice when the refrigerant circuit or process loop demands higher ceilings than standard variants provide.

CBMH marine-certified models

The CBMH200 is available with classification certificates from eight major maritime societies including ABS, DNV-GL, and Lloyd's Register. For shipbuilders and offshore platform engineers, this removes the need for additional third-party testing and supports faster procurement. The unit's gasket-free construction is an advantage in marine environments where vibration and thermal cycling are common performance factors.

Connection options and configuration

CB series units accept external thread, compact flange, weld, or solder connections depending on the model. The CB40 adds internal thread and solder joint options. This flexibility lets the installer match the connection to the existing pipework standard without transition fittings. Plate count is configurable within the model's physical range, ensuring the thermal capacity matches the duty requirements. Because the design is modular and built from standard components, lead times for specific plate counts remain predictable.

FlexFlow and PressureSecure

Plate geometry technology, such as FlexFlow, allows for the tailoring of heat transfer characteristics to specific duty conditions. PressureSecure construction is also featured for applications that impose demanding pressure loads. Both features inform the configuration recommended during the brazed plate heat exchanger sizing process to ensure reliability under operating stresses.

CB series brazed plate heat exchangers appear at multiple points in a facility's thermal circuit. Upstream, they pre-cool or pre-heat process streams before they enter secondary stages or cleanrooms. Downstream, they recover thermal energy from waste streams or reject heat to cooling towers and chillers. The table below maps primary industries to their typical CB series duties and technical requirements.

HVAC and refrigeration

Commercial and industrial HVAC systems use CB series units for zone heating and chilled water distribution. Their turbulence characteristics reduce fouling in closed-loop glycol or water circuits. In refrigeration, the gasket-free construction eliminates a potential leak path. The compact geometry also means the refrigerant side holds significantly less volume than a shell-and-tube condenser. Alfa Laval research indicates that brazed plate heat exchangers can reduce refrigerant charge by approximately 80% compared with shell-and-tube units of equivalent duty, helping to lower procurement costs for refrigerants and limit environmental risk.

Data center cooling

Liquid cooling is essential for high-density server workloads where air cooling reaches its limits. Custom brazed plate heat exchangers have been integrated into coolant distribution units (CDUs) to deliver high cooling capacity in an in-row format. Reference evaluations documented by Alfa Laval have shown CDU capacities in the megawatt range (up to 2.3 MW) from units that utilize compact plate geometries. These units are engineered around seven key parameters to balance heat transfer efficiency, hydraulic performance, and pressure drop, prioritizing minimal footprint per kilowatt of rejected heat.

Semiconductor manufacturing

Semiconductor fabrication requires precise temperature control for process fluids and ultrapure water (UPW) loops. For UPW duties, Alfa Laval's Clean Build process provides heat exchangers pre-cleaned in a Class 10,000 environment according to Federal Standard 209E. These units are wiped with deionized water, flushed with hot deionized water filtered to 0.01 µm, and hydrostatically tested with deionized water. This meticulous preparation reduces contamination risk in delicate wafer preparation and rinsing processes.

Marine and district energy

CBMH models support engine cooling and onboard HVAC on vessels, carrying certifications that meet maritime standards. In district energy, heat exchangers serve as condensers and subcoolers in industrial high-temperature heat pumps. Alfa Laval installations have demonstrated significant CO₂ reductions, such as 6,500 tons per year in specific urban projects, by repurposing waste heat from cooling networks into district heating. In these settings, plate heat exchangers typically occupy about one-third of the construction volume compared to shell-and-tube alternatives.

Operating principle

A brazed plate heat exchanger consists of a package of thin, corrugated stainless-steel plates. A thin copper foil is placed between each plate, and the assembly is placed in a high-temperature furnace where the copper melts and brazes adjacent plates together. This process seals the channels formed between plates and holds the assembly together at every contact point, ensuring pressure resistance. No gaskets are required. The result is a rigid block where two fluid streams flow in alternating channels, allowing for heat transfer through the corrugated plate walls.

The corrugation pattern creates turbulent flow even at low fluid velocities, which increases the convective heat transfer coefficient. This high thermal effectiveness allows the unit to perform the same duty as a shell-and-tube heat exchanger in a fraction of the space. Fluid enters and exits through connections brazed or welded to the front plate. The parallel flow arrangement directs both media through their respective channel sets simultaneously. Because every plate surface participates in the process, there is no wasted volume.

Two thicker outer plates, known as the frame plate and the pressure plate, are brazed to the sides of the plate pack to retain internal pressure. Standard materials for the CB line include type 304 or 316 stainless steel for the plates and connections, with copper as the brazing material. Stainless steel typically accounts for 90% of the unit's weight, while the copper brazing material represents the remaining 10%.

Sizing and selection factors

Correct brazed plate heat exchanger sizing involves balancing thermal duty requirements against allowable pressure drop and physical footprint. Primary factors include:

Plate count. The CB40 accepted 4 to 150 plates, while the CB200 can accommodate 10 to 230 plates. More plates provide more heat transfer area but increase depth and weight. For the CB200, depth in mm is calculated as 11 + (2.7 * n), and weight in kg is 12 + (0.60 * n), where n is the number of plates (excluding connections).

Temperature and pressure. CB series units typically operate within a range of −196 °C to 225 °C and are designed for vacuum service. Maximum pressures vary by circuit: for the CB40, the S3–S4 circuit is rated to 37 bar while S1–S2 is rated to 32 bar. High-pressure variants are available for demanding refrigeration cycles.

Connection type. Standard options include external and internal thread, compact flange, solder, and weld connections. Matching the connection type to the facility's piping standard reduces the need for transition fittings and potential leak paths.

Media properties. Flow characteristics and particle sizes are critical. The CB200 allows a maximum particle size of 1.8 mm, while the CB40 is limited to 0.6 mm. Fluids with higher solid content may require pre-filtration to prevent channel blockages.

Refrigerant charge. Because the internal volume is compact, these units hold up to 80% less refrigerant charge than shell-and-tube units for the same duty. This contributes to lower fluid costs and helps meet environmental standards for refrigerant containment.

Footprint. At identical heat transfer capacities, a brazed plate heat exchanger requires approximately one-third of the space used by a shell-and-tube unit, making it the preferred choice for space-limited installation sites.

Maintenance and longevity

The turbulent flow promoted by the plate corrugations provides a self-cleaning effect that discourages the build-up of scale and particles. These units are gasket-free, meaning they do not requires scheduled disassembly or gasket replacement. Chemical cleaning-in-place (CIP) is effective if performed within material compatibility limits. This design results in low lifetime service requirements compared to openable heat exchanger types.

Comparison with alternative heat exchanger types

The following table compares the typical characteristics of brazed plate units against other common heat transfer technologies.

Gasketed plate heat exchangers are preferred when mechanical cleaning or capacity expansion is necessary. Shell-and-tube units are typically used for extremely high-pressure or high-fouling applications. Brazed plate units are the standard choice for most closed-loop HVAC, refrigeration, and industrial cooling duties where compactness and low maintenance are the primary selection drivers.