The GMC Mechanical Connector sets a new industry standard for the mechanical connection of tubular products.

Utilised for multiple high-fatigue applications, GMC’s connector offers higher fatigue-resistance, faster connectivity, no torquing, and reusability, whilst employing a variety of multifunctional vessels.

ISO 21329 certified and DNV witnessed, the GMC Connector is one of the first mechanical connectors to meet this high standard.

GMC Mechanical Connector Benefits

  • Stronger
  • Longer Fatigue Life
  • Rapid Connection
  • Reusable Make/Break
  • Consistent Quality
  • Available in a Range of Sizes
  • Dynamic Applications
  • DNV Approval to ISO:21329:2004 & API Standard 2RD:2013
  • Patent Protection

GMC Mechanical Connector Applications

  • TLP Tendons (ITC)
  • Caisson Replacements
  • HPHT Well Conductors
  • Drilling / Marine Risers
  • Completion & Work Over Risers (CWOR)
  • FLNG Water Intake Risers (WIR)
  • Intelligently Connected Pipe (ICP)
  • Free Standing Hybrid Riser (FSHR)
  • Steel Catenary Risers (SCR)
  • CRA Clad Risers
  • Pipeline Repair Systems
  • Conductor Supported Platforms
  • Rotating Latch Connector (RLC)

ISO:21329 Testing and Qualification

ISO 21329:2004 specifies requirements and provides guidance for the testing of mechanical connectors for use in pipeline transportation systems for the petroleum and natural gas industries as defined in ISO 13623.

The tests specified in ISO 21329:2004 are intended to form part of the design verification process for connectors. They provide objective evidence that connectors conform to a defined performance envelope.


ISO 21329 was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore structures for petroleum, petrochemical and natural gas industries, Subcommittee SC 2, Pipeline transportation systems.

Click to read a preview of the ISO21329 from the website.

The GMC Mechanical Connector successfully completed all DNV ISO:21329 required testing and was awarded certification in 2010.

  • Fatigue Cycle Testing – All tested connectors met or exceeded DNV “C1” curve. The fatigue life tested 10X better than field welded pipe (DNV E) in all series of tests.

(Read the OTC 2011 paper, “Improved Concentric Thread Connectors for SCRs and Pipelines“)

As of September 2013, ISO:21329:2004 is also classified to meet the API Standard 2RD:2013, Dynamic Risers for Floating Production Systems.

GMC Connector Make-Break Tooling System

Two piece hinge design with three clamp plates:

  • Top Clamp Plate – Holds the cylinders for makeup and breakout
  • Middle Clamp Plate – Engages the box clamp groove during connector and sleeve makeup and breakout
  • Bottom Clamp Plate –
    • Engages the clamp groove on the pin connector during connector makeup and breakout
    • Engages the clamp groove on the sleeve during sleeve makeup and break out


Contact GMC for a live demonstration to see how quick and efficient the process is to connect, as well as, disconnect. [email protected]

GMC Connector Make-Break Tooling System