Subsea EQD’s are required when joining two flexible flow lines or joining a flexible hose to a rigid connection, allowing fluid to be transferred during Subsea operations. The majority of hoses have metallic end fittings commonly known as flanges. Subsea EQD’s allow these flanges to be connected and disconnected efficiently.
Despite rigorous planning and advancements in technology such as Dynamic positioning. Unforeseen events can lead to emergencies. Namely when a vessel loses control. Known as a vessel drift off. Drift off can lead to the transfer being over loaded.
During an emergency it is advantageous to speed up this decoupling often known as an activation or breakaway. The activation sees the Subsea EQD separate and isolate the contents of the flow-line/hose. This activation protects personnel, environment (if valved) and assets.
Passive Subsea EQD’s initiate the activation via an axial pull from an external force such as vessel drift off, whereas active Subsea EQD’s initiate the activation via a hydraulic or electrical override. Secc’s Subsea EQD’s can be a combination of both; this allows the system to disconnected prior to an emergency commencing (active) or during an emergency when an axial load is applied (passive).
High pressure Subsea EQD’s come with a variety of challenges. Primarily substantial separation forces from internal hydrostatic forces.
Example: An end connector with a 76mm seal ID at 22,500 psi (1.5 x WP) has a separation force of 7.2 tonnes.
Balancing the hydrostatic forces to remove the separation loads is essential to allow the Subsea EQD to remain lightweight and offer low break load to protect the flow-lines/hoses .
Secc’s pressure balanced Subsea EQD’s can have break loads as low as 250 kg-f whilst operating at 15,000psi working pressure.
Secc’s unique centralised (single) 1 x tension pin in the Midline Weak Link Subsea EQD removes risk of stress when subjected to bending moments; Unlike inferior Subsea EQD’s that use multiple or offset Tension Pins.
The full-bore design allows for a variety of hazardous and course medias to be transferred without damage to internal components.
100% leak free sealing.
Activation under pressure, flow and load. Secc design, develop, manufacture and supply high-pressure, full-bore Subsea EQD’s globally for over 20 years.
Secc offer the most robust and efficient pressure balanced technology. Unlike pressure compensated and stabilised Subsea EQD’s, which use complex pistons and chambers. Secc’s pressure balanced seal and Subsea EQD technology uses patent geometry to ensure the piston effect from hydrostatic pressure is counteracted (balanced). How it works:
| HOT MAKE HOT BREAK | MIDLINE WEAK LINK | MAXFLOW MIDLINE | |
| TYPE | QUICK CONNECT DISCONNECT (QCDC) | EMERGENCY QUICK DISCONNECT (EQD) | EMERGENCY QUICK DISCONNECT (EQD) |
| OPERATION | ACTIVE & PASSIVE | PASSIVE (ACTIVE OVERRIDE AVAILABLE) | PASSIVE (ACTIVE OVERRIDE AVAILABLE) |
| BORE | FULL | FULL | FULL |
| FLOW PATH | 90° or 45° | 45° | STRAIGHT |
| VALVED | DUAL | DUAL | NONE |
| MAX PRESSURE | 15,000 PSI | 15,000 PSI | 15,000 PSI |
Secc’s patented technology has led the subsea and marine coupling industry in Passive emergency quick disconnects (EQD) and Active Quick Connect Disconnects (QCDC) with unrivalled design attributes (See Secc 19).
Secc’s range have been integrated onto a variety of fixed and flexible systems.
Secc has a clear and proven design philosophy ranging from MAXFLOW to HIGHFLOW to ECOFLOW.
