Views: 0 Author: Site Editor Publish Time: 2026-09-22 Origin: Site
As computing power, power electronics density, refrigeration efficiency requirements, and thermal loads continue to increase, liquid cooling is being used across a wider range of equipment.
A liquid cooling system is not simply a heat exchanger and a coolant. It is a complete fluid-control system involving pumps, piping, heat exchangers, cold plates, reservoirs, filters, sensors, valves, and control logic.
In many applications, the pump is a relatively small component but has a direct influence on coolant flow, pressure stability, temperature rise, system footprint, and long-term reliability.
A micro magnetic gear pump can be considered for liquid cooling circuits that require compact installation, positive-displacement flow, controlled circulation, magnetic-drive fluid containment, and compatibility with specialized cooling fluids.
This article explains how to evaluate a micro magnetic gear pump for liquid cooling, including system architecture, thermal calculations, pressure requirements, coolant compatibility, pump heat generation, product parameters, application scenarios, and engineering selection criteria.
Yes, but the suitability depends on the actual operating point.
A micro magnetic gear pump can be used in selected liquid cooling systems when its:
Flow rate
Differential pressure
Coolant viscosity
Operating temperature
Wetted-material compatibility
Inlet conditions
Motor speed
Control method
Continuous operating requirements
match the cooling-loop design.
The most important point is that a cooling pump should not be selected from maximum flow alone.
The required operating point is determined by the thermal load and target temperature rise, together with the hydraulic resistance of the complete loop.
For data-center liquid cooling, ASHRAE describes architectures involving a facility cooling loop, coolant distribution units (CDUs), and technology cooling systems (TCS). CDUs can incorporate pumps, valves, heat exchangers, temperature/pressure/flow monitoring, and controls.
A liquid cooling system transfers heat from a high-temperature component to a coolant and then rejects that heat through a heat exchanger or another cooling stage.
A simplified liquid cooling loop is:
Heat Source → Cold Plate / Heat Exchanger → Coolant Loop → CDU / Heat Exchanger → Heat Rejection → Return
Depending on the equipment, the architecture may include multiple fluid loops.
Pump
Cold plate
Manifold
Heat exchanger
CDU
Reservoir or expansion volume
Filter
Pressure sensor
Temperature sensor
Flow sensor
Control valve
Leak detection
Piping and quick-disconnect fittings
ASHRAE identifies CDUs as an important interface between facility cooling systems and technology cooling systems. Depending on the architecture, the technology cooling fluid can include water, deionized water, refrigerants, or glycol-based fluids.
For AI and high-density computing, current ASHRAE guidance also describes direct liquid cooling architectures and CDUs with pumping and control functions for higher-density thermal loads.
The pump's role depends on the system architecture.
The facility side may handle relatively large coolant volumes and reject heat through chillers, cooling towers, dry coolers, or other heat-rejection equipment.
The pump must therefore be sized around:
High Flow + System Pressure Loss + Energy Efficiency
This is fundamentally different from a compact equipment-level circulation circuit.
The technology cooling system, or TCS, directly serves the thermal load of IT or equipment.
In direct-to-chip systems, coolant is distributed to cold plates connected to high-power components.
The pump must maintain the required flow through:
Pump → Manifold → Cold Plate → Return Manifold → Heat Exchanger/CDU
Here, pressure drop through cold plates, manifolds, filters and quick-disconnects becomes an important part of pump selection.
A coolant distribution unit can connect the facility loop with the technology cooling loop.
Depending on the design, a CDU may include:
Heat exchanger
Circulation pump
Valves
Sensors
Controls
Filtration
Expansion or pressure-control components
The pump therefore needs to be selected as part of the complete CDU hydraulic design, rather than as an isolated component.
One of the most useful calculations in liquid cooling is the relationship between heat load, coolant flow, and temperature rise.
For a single-phase coolant:
or, using volumetric flow:
Where:
P = heat load, W
Q = volumetric flow, m³/s
ρ = coolant density, kg/m³
cp = specific heat capacity, J/(kg·K)
ΔT = allowable coolant temperature rise, K
Assume a cooling loop removes:
50 kW
with a water-like coolant and a target temperature rise of:
5°C
The approximate required flow is:
143.5 L/min
This calculation is important because it immediately shows why pump sizing must begin with the actual thermal load.
A small micro pump may be suitable for a localized thermal-management loop, compressor cooling circuit, auxiliary cooling circuit, or compact CDU subsystem, but it should not automatically be assumed suitable for a large 50 kW loop.
After calculating flow, determine how much pressure the pump must generate.
The required differential pressure may include losses from:
Cold plates
Manifolds
Tubing
Filters
Heat exchangers
Quick-disconnect fittings
Valves
Elevation
Flow-control devices
The pump operating point should therefore be defined as:
Required Flow + Required Differential Pressure
For a positive-displacement gear pump, a simplified relationship is:
where:
Vd = displacement per revolution
n = rotational speed
Actual flow is lower than theoretical flow because of internal leakage, or slip.
As differential pressure increases, internal slip can increase and actual flow can deviate from the theoretical value.
Therefore:
Do not select a micro gear pump from maximum flow alone. Check the actual flow at the required differential pressure and speed.
This principle is also reflected in Suofu's general pump-selection guidance.
One issue that is often overlooked in liquid cooling is that the pump itself can introduce heat into the system.
The electrical input power does not become entirely useful hydraulic power.
The hydraulic power can be approximated by:
where:
Δp = pump differential pressure
Q = volumetric flow
The difference between input power and useful hydraulic power represents losses associated with the motor, magnetic coupling, bearings, gears, internal fluid friction, electrical components, and other mechanisms.
Not all of those losses necessarily enter the coolant; some are rejected to the surrounding environment.
Therefore, for system thermal modeling, engineers should determine:
How much of the pump's loss is actually transferred to the coolant?
This is more useful than applying a universal “pump temperature rise” number.
A practical validation method is to measure:
Coolant inlet temperature
Coolant outlet temperature
Flow rate
Pump input power
Differential pressure
Motor temperature
Ambient temperature
under the actual operating condition.
If a pump adds several hundred watts of heat to a compact secondary loop, that heat must ultimately be removed by the heat exchanger.
The pump therefore becomes part of the system thermal balance, not merely a fluid-moving device.
A conventional rotating shaft passing through the pump housing requires a dynamic sealing interface.
A magnetic-drive pump transfers torque through magnetic coupling, allowing the motor and pumped fluid to be separated by the pump containment structure.
This design can:
Eliminate the conventional rotating shaft seal interface
Reduce one potential leakage path
Isolate the motor from the pumped fluid
Support compact fluid-system integration
This can be particularly relevant when the coolant is:
Expensive
Chemically sensitive
Difficult to contain
Volatile
Environmentally sensitive
Used in a closed-loop system where contamination or leakage is undesirable
However, magnetic drive does not mean that the complete cooling system is automatically leak-free.
Static seals, O-rings, threaded connections, welded joints, fittings, pump housings, tubing and heat exchangers still need to be validated.
The phrase “liquid cooling” covers very different fluids.
Water and water-glycol mixtures are common in single-phase cooling systems.
Important parameters include:
Glycol concentration
Viscosity
Density
Specific heat
Corrosion characteristics
Operating temperature
Electrical conductivity
Material compatibility
The pump should be evaluated at the actual operating temperature because viscosity changes with temperature.
Specialized cooling fluids may be used in immersion or other equipment-level cooling architectures.
For these fluids, engineers should verify:
Chemical compatibility
Swelling behavior of elastomers
Polymer compatibility
Lubricity
Vapor pressure
Viscosity
Material extraction
Long-term exposure
The same pump configuration should not automatically be assumed compatible with every specialty coolant.
Refrigerant-based cooling introduces additional complexity.
At the pump inlet, the fluid may approach saturation conditions. A pressure drop can cause flashing, producing a gas-liquid mixture.
This changes the pump's operating environment significantly.
The design should therefore consider:
Saturation pressure
Fluid temperature
Inlet pressure
NPSH / available suction conditions
Gas entrainment
Two-phase behavior
Material compatibility
Startup conditions
For refrigerant applications, pump selection must be validated with the specific refrigerant and operating envelope rather than based only on water performance.
Suofu's NP Series covers multiple displacement and flow ranges.
The following table uses currently published product data and should be treated as a selection reference rather than a guaranteed operating point. Actual performance depends on pressure, speed, viscosity, temperature, motor configuration and coolant.
Series | Representative Models | Nominal Displacement | Published Rated Flow Range | Published Reference Differential Pressure* |
|---|---|---|---|---|
NP42 | NP020–NP070 | 0.2–0.7 ml/rev | 0–2.2 L/min | 20 bar |
NP51 | NP100–NP190 | 1.0–1.9 ml/rev | 0–6.0 L/min | 20 bar |
NP60 | NP240 / NP350 | 2.4–3.5 ml/rev | 0–10.5 L/min | 20 bar |
NP98 | NP400–NP1700 | 4–17 ml/rev | 0–55 L/min | 20 bar |
NP106 | NP2600 | 26 ml/rev | 0–65 L/min | 20 bar |
*The published product pages specify the differential-pressure reference with water as the medium. Customized pressure capabilities vary by series and configuration and should be verified against the relevant performance curve.
Depending on the series, published NP specifications include:
Operating speed: up to approximately 4,000 rpm on the listed configurations
Operating temperature: approximately -120°C to +150°C on applicable configurations
Medium viscosity: up to approximately 20,000 cP on applicable product pages
Inlet vacuum: approximately -0.85 bar, speed-dependent, on applicable configurations
Pump body options: SS316, Hastelloy, PEEK and customized materials
Gear/bearing options: PEEK on listed configurations
Shaft: zirconia ceramic
O-ring options: FKM, EPDM, PTFE, FVMQ, CR and FFKM
Motor options: BLDC, AC/VFD and servo configurations depending on series
These specifications are configuration-dependent and should not be treated as universal NP-Series limits.
The selection should follow the required operating point rather than the model number.
For compact thermal-management systems requiring flows below approximately 2.2 L/min, the NP42 family provides four displacement options from 0.2 to 0.7 ml/rev.
Typical engineering applications include:
Small cooling circuits
Laboratory thermal systems
Compact refrigeration equipment
Auxiliary cooling loops
Specialized equipment cooling
The NP51 family covers NP100 through NP190, with published rated flow ranges from 0–2.9 L/min to 0–6.0 L/min.
This range can be considered for:
Compact cooling equipment
Refrigeration circulation
Small CDU subsystems
Equipment thermal management
Compressor cooling
The NP60 family includes NP240 and NP350.
NP350 has a published rated flow range up to 10.5 L/min, with a nominal displacement of 3.5 ml/rev.
The series can be evaluated for:
Medium-flow cooling circuits
Industrial refrigeration
Compressor cooling
Compact liquid cooling equipment
Thermal-management modules
The NP98 family includes:
NP400
NP600
NP900
NP1200
NP1700
Published rated flow ranges extend from 12.6 L/min for NP400 to 55 L/min for NP1700.
This range can be evaluated for higher-flow equipment cooling and refrigeration systems where the actual flow-pressure point falls within the pump's performance envelope.
The NP2600 has a nominal displacement of 26 ml/rev and a published rated flow range of 0–65 L/min.
For this class of pump, engineers should pay particular attention to:
Motor power
Differential pressure
Coolant viscosity
Heat generation
Pipe size
Filter pressure drop
Installation configuration
Before selecting a micro magnetic gear pump, prepare these 10 parameters.
Parameter | What to Provide |
|---|---|
Heat load | kW |
Required flow | Minimum / normal / maximum |
Differential pressure | ΔP at operating flow |
Coolant | Exact fluid name and composition |
Viscosity | Minimum / normal / maximum |
Temperature | Minimum / normal / maximum |
Inlet condition | Flooded, suction, vacuum or pressurized |
Control | Fixed speed, analog, PWM, VFD or servo |
Materials | Pump body, gears, shaft, O-rings |
Operating mode | Continuous / intermittent / start-stop |
Two additional parameters are particularly important for closed-loop cooling:
Particle contamination can affect small internal clearances, gears, bearings and seals.
Suofu's published NP42, NP51, NP60 and NP98 product pages recommend a 400-mesh inlet filter on applicable configurations. The actual filter should also be selected according to pressure drop, flow capacity and coolant compatibility.
Dry-running capability is not universal across the NP Series.
For example, the NP60 product page specifies a limited dry-running condition, while the NP98 page explicitly states that dry running is not recommended.
Therefore:
Never assume dry-running capability from the pump family name alone.
In data-center liquid cooling, pumps may operate inside CDUs or technology cooling systems.
Typical requirements include:
Continuous operation
Stable flow
Controlled differential pressure
Low installation footprint
Coolant compatibility
Monitoring and control
Serviceability
ASHRAE identifies pumps, valves, heat exchangers and instrumentation as components of liquid-cooling distribution systems.
A micro magnetic gear pump is therefore more relevant to compact or localized circulation duties than to every pump position in a large data-center facility.
Direct-to-chip systems place cold plates directly on high-power components.
The pump must overcome the hydraulic resistance of:
Pump → Manifold → Cold Plate → Manifold → Heat Exchanger → Return
The correct pump should therefore be selected using the cold-plate pressure drop and required coolant flow, not simply the thermal power of the chip.
A compact CDU may have strict requirements for:
Installation dimensions
Flow regulation
Pressure stability
Coolant compatibility
Continuous operation
Sensor integration
The pump can be selected according to the actual CDU operating point.
Magnetic-bearing and air-bearing compressors can use dedicated liquid or refrigerant cooling circuits.
The pump may need to handle:
Compact installation space
Refrigerant compatibility
Temperature variation
Pressure differential
Continuous operation
Variable-speed control
Suofu's published compressor-cooling application data includes NP070/NP190 for lower-flow applications, NP350 for medium-flow systems, and NP1700/NP2600 for higher-flow systems.
Outside data centers, micro magnetic gear pumps can also be evaluated for:
Power-electronics cooling
IGBT testing
Battery thermal management
Laboratory cooling
Refrigeration equipment
Specialized process cooling
Compact heat-transfer systems
The same engineering rule applies:
Select from the complete flow-pressure-temperature-viscosity operating point.
The source material provided for this article contains an engineering case involving development of a high-speed cooling pump for a space-computing payload.
According to the supplied project information, the design moved beyond conventional pump speeds toward an approximately 11,000–20,000 rpm operating range, with a compact shaft around the 3 mm scale and a target operating region involving tens to approximately 100 mL/min and around 1–2 MPa.
The engineering challenge was not simply increasing rotational speed.
Higher speed
↓
Smaller pump envelope
↓
Higher shaft-speed stress
↓
Higher gear PV loading
↓
Material and bearing constraints
↓
Need for dedicated validation
This type of application requires the pump to be evaluated as a complete rotating system.
Important validation items include:
Rotor strength
Shaft deflection
Bearing loading
Gear wear
Magnetic coupling torque
Motor thermal behavior
Vibration
Startup behavior
Temperature cycling
Vacuum/environmental conditions
Reliability is not determined by one material or one specification.
A practical reliability model is:
Material Compatibility
Hydraulic Operating Point
Thermal Management
Bearing / Gear Design
Motor Selection
Coolant Cleanliness
Manufacturing Consistency
Validation Testing
The pump should be tested under representative conditions rather than only at room temperature with water.
A meaningful test matrix can include:
Test Parameter | Purpose |
|---|---|
Flow | Verify delivery capability |
Differential pressure | Verify hydraulic operating envelope |
Coolant temperature | Evaluate thermal behavior |
Motor current | Monitor load |
Motor temperature | Check thermal stability |
Pump-body temperature | Identify heat transfer |
Inlet pressure | Evaluate suction conditions |
Vibration | Identify mechanical instability |
Noise | Monitor operating condition |
Long-duration operation | Evaluate reliability |
For specialized projects, a P-Q performance map is much more useful than a single maximum-flow number.
A technically credible article should also explain where the technology has limitations.
A micro magnetic gear pump may not be appropriate when:
The required flow may exceed the practical operating range of a compact positive-displacement pump.
Gear meshing and bearing interfaces must be evaluated carefully where contamination limits are exceptionally strict.
Abrasive particles can accelerate wear of gears, bearings and other wetted components.
For unfamiliar dielectric fluids, refrigerants or specialty coolants, material compatibility and viscosity data should be established before selection.
Flashing and gas entrainment can significantly change pump behavior.
Dry-running limits must be verified for the exact model and configuration.
This is not a weakness of one particular product. It is a fundamental part of engineering pump selection.
For a thermal model, separate three quantities:
Power supplied to the motor and drive.
Only part of the total loss necessarily enters the coolant.
Therefore, instead of assuming a universal heat-generation percentage, obtain measured data under the intended operating point.
A useful test record is:
Flow + ΔP + Electrical Power + Coolant Inlet Temperature + Coolant Outlet Temperature + Ambient Temperature
This creates a data set that can be directly used in the system thermal model.
Yes. It can be considered for selected cooling circuits, particularly compact or localized loops where the required flow, differential pressure, coolant properties and installation dimensions fall within the pump's operating envelope.
The published Suofu NP Series ranges from approximately 0–1.5 L/min to 0–65 L/min, depending on the series and model. For liquid-cooling applications, the actual operating point must be determined from the required flow, differential pressure, coolant and pump speed.
There is no single pressure value for the entire NP Series.
Published product pages specify different differential-pressure and pressure-withstanding values by series and configuration. For example, NP42, NP51, NP60, NP98 and NP106 pages publish different system-pressure capabilities. The final operating point must be checked against the relevant model curve.
The pump can be evaluated for glycol-based coolants, but the exact glycol concentration, temperature, viscosity and material compatibility should be confirmed before selection.
Selected configurations can be considered for refrigerant circulation, but refrigerant applications require specific validation of pressure, temperature, viscosity, material compatibility, inlet conditions and gas-liquid behavior.
No pump should be described as absolutely “zero leakage” without defining the entire system and test conditions.
Magnetic drive eliminates the conventional rotating shaft seal interface, which can reduce one potential leakage path. Static seals and external connections still require engineering validation.
It depends on the exact configuration.
For example, Suofu's NP60 documentation specifies limited dry-running conditions, while NP98 documentation states that dry running is not recommended.
There is no single parameter.
The minimum selection data should include:
Flow + Differential Pressure + Coolant + Viscosity + Temperature + Inlet Condition + Motor/Control
For a single-phase coolant:
The required flow increases when the heat load increases or the allowable coolant temperature rise decreases.
Yes.
The pump's losses can contribute to the thermal load of the coolant loop. For compact systems with a relatively small heat exchanger, this can be significant enough to justify direct measurement.
Not automatically.
Different fluids have different viscosity, density, vapor pressure, lubricity and chemical compatibility. The pump configuration should be validated for the specific coolant.
For an OEM liquid-cooling project, provide the following information:
Category | Required Data |
|---|---|
Thermal load | kW |
Coolant | Exact fluid |
Concentration | % if applicable |
Flow | Min / normal / max |
ΔP | Required differential pressure |
Temperature | Min / normal / max |
Viscosity | Operating range |
Density | Operating range |
Inlet pressure | Minimum / normal |
Installation | Flooded / suction / reservoir |
Control | Fixed / analog / PWM / VFD |
Operating time | Continuous / intermittent |
Cleanliness | Filter requirement |
Materials | Wetted-material requirement |
Motor | Voltage / power / speed |
Interface | Ports / dimensions |
Environment | Ambient / vibration / protection |
Certification | Required regional or application certification |
The more complete this data is, the more accurately the pump can be matched to the cooling system.
A liquid cooling pump should be selected as part of the complete thermal and hydraulic system, not as an isolated component.
For a micro magnetic gear pump, the critical design chain is:
Thermal Load
→ Required Coolant Flow
→ System Pressure Drop
→ Pump Operating Point
→ Coolant Compatibility
→ Motor & Speed Control
→ Thermal Loss
→ Long-Term Validation
Suofu's NP Series provides multiple displacement and flow configurations, ranging from small-flow NP42 models to the NP2600 with a published rated flow range up to 65 L/min.
For liquid cooling applications, the engineering objective is not to select the pump with the largest specification. It is to match the pump to the actual flow-pressure-temperature-viscosity operating point, while validating materials, inlet conditions, heat generation, cleanliness and continuous operation.
For an OEM project, the most useful starting information is:
Coolant + Heat Load + Flow + Differential Pressure + Temperature + Viscosity + Inlet Condition + Motor/Control
That data allows the pump configuration and performance curve to be evaluated against the actual cooling-system requirements.
