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M Series

Diaphragm Membrane Coupling with Stainless Steel Discs in Factory-assembled Packs

M Series coupling range is particularly suited for electric motor and turbine drives in the oil and gas industry. Torque is normally transmitted through two sets of pre-assembled membrane units, separated by a spacer element. The coupling provides a good level of angular, lateral and axial misalignment, while maintaining a high level of balance integrity. In the unlikely event of membrane failure, due to a torque overload, the coupling will disconnect the drive, thus protecting the associated shafts. Standard options for spark resistance are available.

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  • IMG1326
  • M1
  • M2
  • MHSS 2
  • MHSS 3


  • Easy-to-fit cartridge and membrane units.
  • Meets ATEX 95, API 610, and can be supplied to meet API 671.
  • Intrinsic balance meets AGMA class 9.
  • High misalignment capability.
  • Stainless steel flexible membranes for maximum life.
  • Excellent power-to-weight ratio.
  • Cartridge membrane design reduces stock inventory.
  • The replaceable membrane units can be fitted to any length spacer to maximize the use of inventory held.
  • Low imposed forces on machinery leading to a reduced machinery vibration and maximized bearing life.
  • A bearing is fitted between the guard rings; in the very unlikely event of membrane failure, the spacer will freely rotate, giving no flow indication on the pump permitting the operators to shut down the machinery safely.
  • Anti-fly pretention of the spacer in the unlikely event of membrane failure.
  • Standard API puller holds incorporated into hubs.


Maximum Shaft


Maximum Torque

95,500 Nm (845,000 lbf/in)

Speed Limits

24,000 rpm

Temperature Limits

5°F to 300°F/-15°C to 150°C

Recommended Applications

  • Process Pumps
  • Electric Motors
  • Gearboxes
  • Steam Turbines
  • Gas Turbines
  • Centrifugal Compressors
  • Other Compressors
  • Other Rotating Equipment
  • Generators
Works with:
Type 48HP Type 48HP
Type 48LP Type 48LP
Type 48MP Type 48MP
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