What is marine breakaway coupling?

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A Marine Breakaway Coupling (MBC) is a crucial safety device used during fluid transfer in offshore environments, whether it’s for loading or discharging a vessel.

  1. Purpose and Function:
    • The MBC is installed into hose transfer systems at offshore tanker discharging or loading terminals.
    • Its primary purpose is to prevent oil spills and protect the transfer system from damage in two critical scenarios:
      • Tanker Breakout: This occurs when a vessel moves off station and breaks its mooring hawser or experiences a similar incident.
      • Excessive Pressure Surge: This results from the inadvertent closure of the export tanker manifold valve during full flow conditions.
    • When the pre-set parting load is exceeded, the MBC activates:
      • The valves close and shut off the line on one or both sides of the parting point as required.
      • The coupling separates, relieving tension in the hose system before it can rupture.
      • The closure may be controlled or instantaneous, depending on the MBC’s specification for the system.
  2. Benefits of Installing an MBC:
    • Environmental Protection: Minimizes the risk of oil spills, reducing pollution and costly cleanup efforts.
    • Equipment Safeguarding: Protects the hose string, mooring buoy structure, storage vessel off-take arm, sub-sea P.L.E.M., shuttle tanker, or barge manifold.
    • Downtime Reduction: Minimizes costly vessel and transfer system downtime caused by spills and damage.
    • Unaffected by Pressure Fluctuations: The MBC remains functional during normal transfer operations, even with pressure fluctuations.
  3. Types of MBC:
    • Petal Valve MBC: Suitable for heavy products like crude oil and heavy fuel oil.
    • Flip-Flap MBC: Ideal for low-viscosity products such as gasoline, kerosene, diesel, and LPG.
    • The Gall Thomson team collaborates with users to determine the exact specification based on factors like terminal type, product being transferred, flow rate, and product viscosity.

What is the function of breakaway coupling

The function of a breakaway coupling is to safeguard fluid transfer systems by preventing spills and minimizing damage in critical scenarios. Here are the key functions:

  1. Preventing Spills:
    • Breakaway couplings are installed in fluid transfer lines (such as hoses) at offshore terminals or loading/unloading points.
    • They activate when specific conditions are met, such as excessive tension or pressure fluctuations.
    • By closing valves and separating the coupling, they prevent spills during incidents like tanker breakout or sudden valve closure.
  2. Protection Against Damage:
    • Breakaway couplings protect various components:
      • Hose String: Prevents hose rupture due to excessive tension.
      • Terminal Infrastructure: Safeguards mooring buoys, storage vessel off-take arms, and sub-sea P.L.E.M. (Pipeline End Manifold).
      • Shuttle Tankers or Barge Manifolds: Ensures their integrity.
    • Reduces downtime caused by spills and repairs.
  3. Activation Mechanism:
    • When tension or pressure exceeds a pre-set limit:
      • Valves close to isolate the system.
      • The coupling separates, relieving tension.
      • Closure can be controlled or instantaneous based on the coupling’s design.
  4. Types of Breakaway Couplings:
    • Petal Valve MBC: Suitable for heavy products (e.g., crude oil).
    • Flip-Flap MBC: Ideal for low-viscosity products (e.g., gasoline, diesel).

Who makes marine breakaway couplings

Gall Thomson is a leading manufacturer of Marine Breakaway Couplings (MBCs), which play a crucial role in ensuring safety during fluid transfer operations in offshore environments.

Gall Thomson Marine Breakaway Couplings:

    • Purpose: MBCs serve as an identifiable safety fuse in offshore fluid transfer systems.
    • Activation Mechanism:
      • When there’s undue tensile load on the hose string or an unacceptable surge in flow, the MBC automatically activates.
      • It shuts off product flow and separates to prevent spills and damage.
    • Evolution and Design:
      • Gall Thomson MBCs have evolved over nearly 40 years based on operational and environmental factors.
      • Variables considered include media type, flow conditions, hose characteristics, maintenance, and more.
      • The latest generation MBCs are designed and manufactured based on real-world experience and consistent investment.
    • Industry Standard: Gall Thomson MBCs are compact, lightweight, durable, and proven worldwide for operational efficiency.
    • Protection and Benefits:
      • Reduces spill risk, protecting the environment and minimizing cleanup costs.
      • Minimizes damage to transfer systems and assets.
      • Enhances workforce safety.
    • Valve Types:
      • Petal Valve Type: Suitable for higher viscosity products like crude oil. Offers zero headloss and full piggability.
      • Flip-Flap Valve Type: Designed for low-viscosity products such as kerosene and LPG.
  2. Other Manufacturers:
    • MIB Italiana: They produce the MIBreak and Flip Flap, emergency disconnection systems for the oil and gas industry.
    • Stäubli: Known for safety breakaway couplings, including those for marine applications.

What is the difference between a breakaway cable and a secondary coupling

Certainly!  The difference between a breakaway cable and a secondary coupling for towing trailers and caravans:

  1. Breakaway Cable:
    • Purpose: A breakaway cable is a vital safety feature for braked trailers and caravans.
    • Function: In the event of the coupling detaching, the breakaway cable is designed to:
      • Apply the handbrake of the towed vehicle.
      • Allow the trailer to break away from the towing vehicle.
      • Bring the trailer to a controlled stop.
    • Scenario: Imagine the ball hitch neck or coupling breaks while towing. The breakaway cable ensures that the trailer doesn’t continue uncontrollably.
    • Replacement: If the cable snaps due to activation, it will need to be replaced.
  2. Secondary Coupling:
    • Purpose: A secondary coupling is required for unbraked trailers (e.g., smaller trailer tents without brakes).
    • Function: Unlike the breakaway cable, a secondary coupling restrains the trailer. It remains intact and unbroken even if the ball hitch neck or coupling breaks.
    • Attachment: The secondary coupling must be securely attached to the towing vehicle’s tow frame.
    • Scenario: When towing a trailer without brakes, the secondary coupling prevents the coupling from touching the ground if the trailer becomes detached from the towing vehicle.

What is the work of coupling

Certainly! A coupling serves the critical function of connecting two separate parts or components. Here are some common contexts where couplings are used:

  1. Mechanical Couplings:
    • Purpose: In mechanical systems, couplings join rotating shafts or components.
    • Function:
      • Transmit Torque: Couplings transfer rotational force (torque) from one shaft to another.
      • Compensate Misalignment: They accommodate slight misalignments between shafts.
      • Dampen Vibrations: Some couplings dampen vibrations and shocks.
    • Examples:
      • Flexible Couplings: Allow for misalignment and absorb shocks.
      • Rigid Couplings: Transmit torque without flexibility.
      • Universal Joints: Connect non-collinear shafts.
      • Gear Couplings: Transmit high torque.
      • Oldham Couplings: Compensate for axial misalignment.
      • Jaw Couplings: Simple and cost-effective.
      • Disc Couplings: Transmit torque while allowing angular misalignment.
  2. Electrical Couplings:
    • Purpose: In electrical systems, couplings connect electrical conductors.
    • Function:
      • Transfer Electrical Signals: Couplings allow signals to pass between components.
      • Isolate Circuits: Some couplings provide electrical isolation.
      • Join Wires: They connect wires or cables.
    • Examples:
      • Wire Nuts: Twist-on connectors for electrical wires.
      • Terminal Blocks: Connect multiple wires.
      • Coaxial Cable Connectors: Join coaxial cables.
      • RJ45 Connectors: Used in Ethernet networking.
      • USB Connectors: Link devices to computers.
  3. Fluid Couplings:
    • Purpose: In hydraulic or pneumatic systems, fluid couplings connect pipes or hoses.
    • Function:
      • Transfer Fluid: Couplings allow fluid (liquid or gas) to flow between components.
      • Seal Joints: Prevent leaks.
      • Disconnect Easily: Some couplings enable quick disconnection.
    • Examples:
      • Camlock Couplings: Quick-connect fittings for hoses.
      • Hydraulic Couplings: Used in hydraulic machinery.
      • Quick-Release Couplings: Rapidly connect and disconnect hoses.
      • Pipe Couplings: Join pipes in plumbing systems.

Why is it called a coupling

The term “coupling” derives from its fundamental purpose: to connect or join two separate components. Whether in mechanical, electrical, or fluid systems, a coupling serves as the essential link that enables efficient transmission of forces, signals, or fluids. The word itself embodies the concept of unity and cohesion, emphasizing the role of these devices in creating a functional whole. So, next time you encounter a coupling, remember its name reflects its vital function.

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