The requirements for pumping hydrocarbons in petrochemical plants and refineries are very high in terms of performance, efficiency, and emission limits. An increasing number of process pumps with API 685 magnetic couplings are being used for these types of applications. For several years, EagleBurgmann and KSB South Africa, a leading supplier of pumps and valves, have been working together to design a magnetic coupling pump. The new zero-leakage RPHmdp API 685 refinery pump was developed utilizing high-efficiency magnetic couplings from the proven EagleBurgmann MAK685 series to seal the shaft.
The EagleBurgmann MAK685 Magnetic Coupling
The universal MAK modular concept for pumps – for initial installation or retrofitting – is based on two proven magnet variants, depending on the requirement: samarium-cobalt for operating temperatures up to 572˚F (300°C), and neodymium ferrum boron up to max. 248˚F (120°C). As a result, the coupling size can be optimally adapted to the required operating conditions and capacities.
Different containment shell materials with low electrical conductivity for minimum eddy current losses are offered as well. A carbon fiber reinforced PEEK containment shell is used for applications up to 248˚F (120°C), which completely eliminates eddy currents and seals with a maximum degree of efficiency. Due to the occurring loads, a metallic high-performance containment shell with a laminated structure, which reduces eddy current losses to a minimum, is used for more demanding applications up to 572˚F (300°Cº) with higher speeds and pressures.
The magnetic couplings are supplied with high-precision sliding bearings to securely support the pump shaft. The bearing absorbs the axial and radial forces of the impeller; an effective product circulation in the interior of the magnetic coupling ensures lubrication and heat dissipation and guarantees high operational safety – even for low-viscosity media.
Bearings that can be cooled or heated are also optionally available. The gas from problematic gas-containing media is removed from the containment shell chamber by a hollow shaft that prevents the risk of the sliding bearings running dry.
Advantages of the MAK685
- Optimized circulation guidance to improve the bearing load capacity and cooling of the containment shell
- High-grade sliding bearing and magnetic materials enable a wide range of use
- No eddy current losses due to carbon fiber reinforced PEEK containment shell and therefore no heating – increased safety, especially for high speeds
- Resistance to a great number of aggressive media
- Resistant to jolts caused by ductile material properties
- High pressure limit with 609 psi (42 bar), in conformance with API 685
Torque: Up to 1,385 ft-lbs (1.879 Nm) (magnet material: NdFeB)
Up to 994 ft-lbs (1.348 Nm) (magnet material: SmCo)
Pressure: Up to 653 psi (45 bar)
Temperature: -40˚F – +572˚F (-40°C - +300°C)
Rotational speed: 3,600 rpm
For more information on the MAK685 series of magnetic couplings, contact us at email@example.com.