Mid Line Weak Link (MLWL)

The MIDLINE WEAK LINK (MLWL) is a full-bore, pressure-balanced Breakaway Coupling. Designed to be situated between two flexible hoses. Facilitating Emergency Quick Disconnect (EQD).

It is designed to breakaway in an emergency. The patented design automatically seals the bore, providing 100% zero leak. Protecting assets, safety and preventing fluid loss to the marine environment.

The balanced geometry provides the low pressure drop possible across the Coupling and zero axial hydrostatic force on the retention system. Allowing for relatively low breakloads to be set: protecting assets and systems.

Where other subsea offerings are comprised of complex “compensated” (not balanced) mechanical/hydraulic chambers and pistons.

The MLWL is retained by a 1 x “Tension Pin” set to the specified break load. Utilising 1 x centralised, Tension Pin reduces uneven and over loading over tension pins when multiple tension pins are used.

Its mid-hose installation provides operators and service companies complete flexibility to position the MLWL system subsea, marine or topside. This makes it an ideal solution in a variety of applications, and an excellent alternative when a fixed/mounted EQD is not appropriate.

Secc’s pressure balanced geometry has been utilised for over 20 years.


✅ Passive Breakaway – Set to specified Break load up to 5 Tonne
✅ Integrated valve closure – 100% Zero Leak
✅ Activation under full pressure and flow
✅ Full-bore, HIGHFLOW, minimal pressure drop across the Coupling (No Valve trim in bore)
✅ Pressure balanced design
✅ High Pressure up to 15,000Psi WP
✅ Flexible installation between flexible hoses/flow lines
✅ Designed and tested in line with API6A 17D to PSL3 PR2 for Other End connections (OEC)
✅ Option protection jacket
✅ Quick to reset
✅ Lifting Lugs
✅ Tether points
✅ Field proven
✅ Patented
✅ Hydraulic or Electrical override (Optional)
✅ Transit protection (Optional)
✅ Position indication (Optional)
✅ Secc Global service, parts and support

Compatible with a wide range of fluid media, including but not limited to:

  • Gas
  • Oil
  • Gasoline
  • Water
  • Hydraulic fluid
  • Acid stimulation
  • Scale inhibitors
  • Cement for P&A work
  • Mud/slurry


  • Intervention
  • Ship to Ship fluid transfer
  • Cementing and P&A work
  • Work over & well stimulation
  • Drilling operations
  • Pipeline pre-commissioning and commissioning
  • Vessel to rig fluid transfer
Bore Size

1” - 4”

Design Pressure

Up to 15,000 psi [1034 bar]

Water Depth

Up to 10,000 ft [3048m]

Operating Temperature

0ºC to 60ºC

End Connections

API, Norsok or ASME Flange,
Destec or Grayloc Hubs
Fig 1502 Hammer Union
H.P. Autoclave
Threaded (JIC or NPT)
Weld Preparation


HNBR, Viton (FKM) or Perfluoroelastomer (FFKM)


Super Duplex, Inconel and S316 Stainless Steel

Design Standard

API 6A and API17D to PSL3G PR2

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