MHS Series

M Series Multiple Membrane Straight Diaphragm Coupling with Stainless Steel Discs in Pre-assembled Single Diaphragm Packs

With John Crane’s Metastream® MHS Series coupling range, the torque is transmitted through pre-assembled packs with a built-in safety bush to help protect your equipment. The coupling meets API 610 and provides a strong level of angular, lateral and axial misalignment, while maintaining a high level of balance integrity. In the unlikely event of membrane (disc) failure due to a torque overload or excessive misalignment, the coupling will disconnect the drive and run on the safety bush, permitting the driven machine to safely come to rest without further damage to the equipment. This series is available with a single pre-assembled pack (MHSO) for short shaft separations on three bearing applications and with two pre-assembled packs (MHSS) with a high strength spacer piece between for longer shaft separations on four bearing applications. The pre-assembled pack(s) are available in numerous material combinations, including a spark resistant option.



  • California Residents: PROPOSITION 65 WARNING
  • Easy-to-fit cartridge and membrane units.
  • Meets ATEX, 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 holes incorporated into hubs.

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