Klaus Union Gmbh & Co. KG - Logo
Blumenfeldstraße 18
D-44795 Bochum
Tel: +49 234 4595-0
Fax: +49 234 4595-7000

Magnet drive pump according to API 685

This API 685 compliant pump for refineries and petrochemical plants is based on our non-shaft seal and modular centrifugal pumps with magnetic couplings.

Design Features:

  • Process oriented design
  • Magnet drive
  • Leakproof
  • Horizontally mounted
  • Modular system
  • Center mounting bracket 
  • Oiled ball bearing

Single-stage pumps

Technical data
Q up to 3500 m³/h with 50Hz / up to 4200 m³/h with 60Hz
H up to 150 m with 50Hz / up to 215 m with 60Hz
t from -120°C up to +450°C
p up to PN 50 / Class 300
Special constructions and higher outputs are available.

The performance characteristics can be downloaded here

Standard construction




Pump casing

316 austenite

Cast steel


316 austenite

316 austenite

Isolation shell

Hastelloy C

Hastelloy C

Pump shaft

316 austenite

316 austenite / C-steel

Bearing lantern/bearing carrier

Cast steel

Cast steel

Drive shaft



Further materials such as the following are available: H-2 (Hastelloy C), A-9 (alloy-20), T-1 (titanium), D-1 (duplex).

Performance data for multi-stage pumps

Technical data
Q up to 450 m³/h with 50Hz / up to 540 m³/h with 60Hz
H up to 900 m with 50Hz / up to 1300 m with 60Hz
t from -120 °C up to +450 °C
p up to PN 150
Special constructions and higher outputs are available.

Identification code:

Suffixes (designs):


heated pump casing


jacketed bearing lantern


internal filter


external feeding, internal secondary-flow boring enclosed


external flushing and venting; internal secondary-flow boring non-enclosed


external secondary flow with main flow filter per DGRL


double isolation shell




Design variants

Heated pump H1 and/or H2
The pumps are outfitted with a heat jacket and pump casing (H1) and/or a heat jacket in the bearing lantern (H2). Both heat jackets can be realized either separately or in conjunction with a bypass line. The heat jackets in the standard construction are rated for operating pressure of 16 bar at 200 °C (steam) or 6 bar at 350 °C. The heat jackets can also be used for cooling.

Internal filter F
When solids-containing liquids are being transported, the internal filter prevents inadmissibly large particles from entering the flow channels, and from there the magnetic coupling and internal bearings.

External feed and flushing connections E1 and E2
These external connections allow for external flushing, feeding and/or venting. Connection E1 is used in situations where a continuous feed into the magnet drive is desired. Connection E2 is used suitable for short-term flushing, or for external venting of the magnetic coupling.

Double isolation shell D
The double isolation shell should be used in situations requiring a high level of safety. The unit consists of two interlocking isolation shells, both of which are rated for the relevant operating conditions. If one of the two units is damaged, the casing still remains leaktight. The gap between the two units can be monitored.

Inducer J
Inducers are often used in cases where the installation's NPSH values are extremely low. Inducers substantially reduce pump NPSH throughout the installation without altering pump characteristics. Inducer J can be retrofitted on existing pumps, in most cases with only a minimum amount of pump modification.