Hermetic magnetic drives for pumps and agitators · Torque and speed, can pressure, magnet material and temperature, eddy-current loss, bearings and solids
A magnetic coupling transmits torque through a closed, non-magnetic can by means of permanent magnets on an outer and an inner rotor, so a pump or agitator shaft needs no dynamic seal and the medium stays hermetically enclosed. Settle three things before ordering: the torque, speed and duty the coupling must transmit, the pressure and temperature the can and magnets must withstand, and the can design, bearings and medium properties that set losses and wear.
Permanent-magnet synchronous couplings with a containment can for sealless pumps, agitators, mixers and reactors, including their product-lubricated bearings. Open magnetic couplings without a can, eddy-current couplings and drives, hydrodynamic fluid couplings and mechanical seals are outside this page; mechanical seals and shaft couplings have their own pages.
01
EagleBurgmann describes its magnetic couplings as a hermetic sealing solution for pumps, agitators and aerators that keeps dangerous or precious media isolated in a closed circuit, with no contact between the torque-transmitting elements. Its MAK66 for standard applications is rated for shaft diameters up to 40 mm, 25 bar, 3,600 rpm and a maximum torque of 462 N·m. Its temperature range is −40 to +250 °C with samarium-cobalt magnets but up to +120 °C with NdFeB magnets. [1]
Its NMB series for applications to API 685 is rated for 45 bar, torques of 18 to 1,879 N·m and the same temperature limits by magnet material. [2] Its SMAK coupling for mixers and agitators — top, bottom or side entry, with electropolished wetted parts — covers vacuum to 7 bar, −40 to +150 °C, up to 400 rpm and 270 N·m (bottom drive) or 330 N·m (top drive). [3]
A linked supplier of high-pressure magnetic drives for reactors quotes maximum torques from 1 to 12,000 N·m (for reference) with wetted parts in stainless steels, Hastelloy, titanium, nickel, Inconel or Monel. [5]
Editorial note: a magnetic coupling decouples (slips) if the load torque exceeds its rating, and the magnet temperature limit — not only the process temperature — decides between SmCo and NdFeB. Include start-up torque and the hottest can temperature in the request. [6]
Give the supplier the pump or agitator type and drive arrangement, motor power and speed, maximum and start-up torque, design pressure, process and can temperature, medium (pH, viscosity, solids content and size), shaft diameter, required standard (for example API 685), can material and any monitoring (temperature or speed).
02
EagleBurgmann's NMB series uses a can of PTFE-sealed insulated rings with a slotted outer can, which it says keeps eddy-current losses to about 2% of motor power, giving energy savings compared with solid Hastelloy cans. [2] Its MAK66 offers Hastelloy or Inconel cans for high performance, an optional high-efficiency can and a product-lubricated sliding bearing. [1]
The MAK66 operating range lists pH 0–14, viscosity 0.3–5,000 mPa·s with silicon-carbide bearings, and solids of at most 0.1 mm, 5% by weight and 700 HV grain hardness. [1] EagleBurgmann's overview adds single- and double-walled cans and an additively manufactured can with an integrated temperature-sensor hole for condition monitoring, for temperature-sensitive applications up to 40 bar. [4]
Editorial calculation: at about 2% eddy-current loss, a 55 kW motor would put about 1.1 kW of heat into the can region (0.02 × 55 kW). The flow through the can space must carry that heat away, which matters with media near their boiling point or temperature-sensitive products. [2]
A linked magnet maker describes magnetic couplings as an outer rotor, an inner rotor and an isolating cover, with alternating magnet poles on ferromagnetic carriers, and lists torque limiting and handling of shaft misalignment among their properties. [6]
03
Suppliers linked to this page list magnetic couplings; each card links to the page reviewed.
The listings reviewed range from pump and agitator couplings with metallic and high-efficiency cans to high-pressure magnetic stirrer drives for reactors and custom NdFeB coupling assemblies; ask each for the torque at your temperature, can material and loss, and bearing material.
04
This is a functional reference built from the sources cited; it is not one maker's specification.
| Part | Role | Fix in the order |
|---|---|---|
| Outer rotor | Motor-side magnets. [1] [6] | Magnet material. |
| Inner rotor | Process-side magnets, in the medium. [1] | Magnet; encapsulation. |
| Can | Pressure boundary; eddy-current loss. [2] [4] | Material; design; pressure. |
| Bearings | Product-lubricated sliding or roller. [1] [4] | Material (SiC). |
| Monitoring | Can temperature or speed. [4] [3] | Sensor type. |
| Flanges | Weld-in or screw-in on vessels. [3] | Connection. |
05
A magnetic coupling quotation needs values for your pump or agitator. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Rated Torque (N·m) | Up to 462 (MAK66); 18–1,879 (NMB). [1] [2] | Torque at temperature. |
| Maximum Speed (rpm) | 3,600 (MAK66); 400 (SMAK). [1] [3] | Limit. |
| Operating Temperature (°C) | −40 to +250 SmCo; to +120 NdFeB. [1] | Range by magnet. |
| Torque Transmission Efficiency (%) | Eddy-current loss about 2% (NMB can). [2] | Loss at duty. |
| Shaft Diameter Range (mm) | Up to 40 (MAK66, SMAK). [1] [3] | Bore. |
| Air Gap (mm) | Rotor-to-can clearances. | Gap; can thickness. |
| Magnet Material | Samarium cobalt or NdFeB. [2] | Grade. |
| Housing Material | Can in Hastelloy or Inconel; wetted alloys. [1] [5] | Material. |
| Weight (kg) | Per coupling. | Weight; inertia. |
06
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Equipment: [pump; agitator; reactor; drive position] Drive: [kW; rpm; start-up torque] Pressure: [design; test] Temperature: [process; can] Medium: [pH; viscosity; solids] Standard: [API 685; other] Can: [material; high-efficiency] Monitoring: [temperature; speed]
These companies list magnetic couplings.
Lists MAK, NMB, SMAK and other magnetic couplings and bearings for sealless pumps and agitators.
Product scope checked 2026-10-11
Lists high-pressure magnetic coupling drives for reactors from lab to industrial scale.
Product scope checked 2026-10-11
Lists NdFeB magnetic coupling designs for pumps and agitators.
Product scope checked 2026-10-11
Lists magnetic couplings among its magnetic assemblies.
Product scope checked 2026-10-11
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
EagleBurgmann lists −40 to +250 °C with samarium-cobalt magnets and up to +120 °C with NdFeB. [1]
EagleBurgmann says its NMB high-efficiency can keeps eddy-current losses to about 2% of motor power. [2]
EagleBurgmann lists 25 bar for MAK66 and 45 bar for its NMB series. [1] [2]
EagleBurgmann's SMAK series serves mixers and agitators in top, bottom or side-entry drives. [3]
Sources checked 2026-10-11. EagleBurgmann is a seal and magnetic-coupling maker publishing operating ranges; Huixin and Tongchuang are linked suppliers.
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