Compact Body, Core Power for Computing — The JONSN MGA Magnetic Gear Pump Dedicated to Liquid Cooling The microchannel hydraulic diameter of a modern GPU cold plate is typically only 200–500 μm. Particles larger than 50 μm can cause blockage, while contin
2026-10-16
The microchannel hydraulic diameter of a modern GPU cold plate is typically only 200–500 μm. Particles larger than 50 μm can cause blockage, while continuous flow pulsation accelerates erosion and creates a risk of local dry-out. When dozens of cold plates are piped in parallel on a single loop, any flow deviation in one branch translates directly into a higher temperature on that GPU — and triggers throttling. Passive resistance balancing is approaching its limit; active branch metering is becoming a new requirement for cold-plate-level hydraulic systems.
Once a single rack pushes past 100 kW, the real difficulty is no longer “is the total flow rate enough?” but “is the flow delivered to every cold plate consistent?”. At the same time, the space available for the pump keeps shrinking. Inside the rack, alongside the cold-plate manifold, or in the micro CDU of an edge node, there is no longer any room for a “fist-sized” pump. The industry needs a more compact, controllable and zero-leakage end-point power unit.
▼01 Five Real Challenges in Cold-Plate-Level Pumping
Item | Issue | JONSN Solution |
①Refrigerant viscosity is low | Low viscosity leaves the pump’s friction pairs in boundary lubrication, leading to wear and shortened service life | Friction-pair materials and pressure-bearing structure selected for low-viscosity media; micron-level clearance control and stable meshing keep wear under control |
② Micro leakage can cause safety incidents | Refrigerant escaping causes fluid imbalance, GPU burnout and greenhouse gas emissions, creating safety risks in a live IT environment | Fully sealed magnetic coupling structure with no dynamic seal; the medium is confined inside the pump cavity for zero external leakage |
③ Branch flow competition raises remote cold-plate temperature | Passive distribution relies on uniform branch resistance; once operating conditions change, flow becomes unbalanced and is difficult to correct online | Positive-displacement output with stable displacement; adding a small controllable pump to each branch provides an independent, stable flow reference |
④ 200–500 μm microchannels cannot tolerate pressure shocks | Microchannels are sensitive to pressure fluctuation; pulsation erodes the flow path and easily causes local dry-out in high-heat-flux zones | Optimized gear profile reduces pulsation and delivers near-continuous DC output, protecting the microchannels and ensuring uniform temperature |
⑤ Rack space is tight and pump mounting is constrained | CDU and cold-plate piping are compact, requiring a miniaturized pump body that still allows for maintenance | Compact body with a 38 mm diameter supports a one-pump-per-loop layout; even in dense rack installations, maintenance clearance is preserved |
Below are the questions most frequently raised by liquid-cooling integrators and server OEMs during pump selection, together with the corresponding JONSN solutions.
▼02 A Pump Dedicated to Liquid Cooling Systems: JONSN-MGA Specifications
Item | Specification |
Model | MGA micro magnetic gear pump |
Delivery medium | Refrigerant / fluorinated fluid |
Rated flow | 1200 mL/min |
Working differential pressure | 1.5–3 bar |
Pressure resistance | 2.5 MPa |
Medium temperature | 25–60 °C |
Sealing type | Magnetic coupling, static seal |
Material options | SS316L |
Shielded brushless motor | 24 V / 15 W / 30 W |
Compact dimensions | Ø38 mm, 65 mm length |
Continuous operating life | >30,000 hours |
▼03 Application Boundaries: A Side-by-Side Comparison with Common Pump Types
Comparison dimension | JONSN Magnetic Gear Pump (MGA) | Small Centrifugal Pump | Diaphragm Pump | Peristaltic Pump |
Behaviour with low-viscosity media | Positive-displacement output; excels at maintaining predictable displacement at low viscosity | Low efficiency at low specific speed; easily drifts away from the best efficiency point | Can transfer fluid, but check-valve sealing degrades at low viscosity | Relies on tubing rebound; low viscosity does not affect displacement, but tubing is a consumable |
Leakage boundary | Magnetic-coupled static seal, zero external leakage | Depends on the shaft seal type; seals have a wear cycle | The diaphragm is a static seal, but fatigue life is finite | Tubing is the weak point; a rupture means external leakage |
Output pulsation | Low pulsation, close to direct current | Smooth | Significant pulsation; usually requires a damper | Pulsed output with a pronounced cycle |
Size and integration | 38 mm diameter; can be embedded directly into the manifold or at board level | Constrained by impeller and volute geometry; difficult to compress | Includes a drive mechanism; bulky overall | Pump head is small, but an external drive assembly is required |
▼04 Customer Feedback and Application Scenarios
The R&D team of JONSN has collaborated with a North American customer for technical research and development. Through customized design, the JONSN MGA magnetic drive gear pump has been successfully developed. Mass production has been realized, and over 1,000 pumps have been successively delivered for a large liquid-cooled computing power center project of the North American client. The duty requires refrigerant delivery accurate to 1200 mL/min at a differential pressure of 2 bar, with a working temperature of 25–60 °C.
Customer feedback: The flow accuracy and pressure stability of the JONSN MGA magnetic gear pump fully meet the project design targets. Compared with the previously imported UK pump solution, it performs outstandingly in precision refrigerant delivery for liquid cooling. On-site operation and maintenance are simple, providing a reliable guarantee for the continuous and stable operation of the computing center’s liquid cooling system. Future capacity expansion projects will continue to use JONSN fluid products.
A typical liquid cooling loop: CDU outlet → distribution manifold → [ JONSN-MGA (independently driven on this branch) ] → cold-plate microchannels → return manifold → plate heat exchanger → back to the CDU. In this topology, the flow of each branch is set directly by that branch’s pump and is no longer entirely dictated by the parallel resistance distribution.
JONSN has long served application sites with hard requirements for “micro flow, low pulsation and zero leakage”: semiconductor advanced packaging and CMP, chromatography and biological laboratory fluid preparation, medical devices, fine chemical metering, and electrolytic hydrogen production. What these fields share is that the flow rates are very small, but the cost of error is very high. Migrating a micro gear pump platform already proven in low-viscosity, low-shear and corrosion-resistant duties to the cold-plate end of liquid-cooled servers is JONSN’s natural path into the computing thermal management arena.
38 mm is only the MGA’s physical size. What has truly been compressed are the tolerances, the leakage and the uncertainty at every single step.