Page 196 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

“Marsh Marine connectors,” referring to the original manufacturer of these first commercial under- water connectors.
Rubber molded to metal bodies
By molding a rubber connector into a metal body, greater strength and stability are added to the product along with positive and stronger keying and locking. The connector is more robust and able to withstand more abusive environments. This configuration is often implemented as a metal- bodied bulkhead mating to a rubber-molded plug connector.
Metal shells with molded inserts
Molded connector inserts can be O-ring sealed into mating metal shells. This configuration offers secure O-ring sealing technology and isolation of the connector elements from the working environment. They are available in a wide variety of sizes and with a large range of inserts at mod- erate cost.
Metal shells with glass-to-metal seal inserts
Electrical contacts can be glass sealed into metal inserts for more demanding applications of pressure and temperature. In addition, they can withstand high open face pressures. Because elasto- meric seals are not used, these connectors do not typically degrade over time, making them popular in military applications where long-term high reliability is crucial. Due to their tolerance to high temperature, glass-to-metal seal connectors are also common in down-hole applications. Due to the sophisticated manufacturing process, glass-to-metal seal connectors are moderately expensive.
Fluid-filled underwater mateable
This style of connector is typically a PBOF assembly incorporating redundant sealing barriers to the environment. This enables the connector to be wet mated by an ROV. Available in electric, optic, hybrid configurations and in high-voltage and/or high-amperage models, they are often used in offshore oil and gas installations as well as the nodes of ocean observatories. Fluid-filled under- water connectors are at the high end of the cost spectrum.
Penetrators
Where systems do not need to be rapidly disconnected, a penetrator may serve as a cable termi- nation and interface to equipment modules. Penetrator construction follows roughly the same con- figurations as mentioned above for connectors.
8.5.1 Mated pairs
Mated pairs are the assembly created by combining matching halves of a connector combination. In hard shell connectors (both metallic and epoxy), there is an engagement sequence that is fol- lowed. An alignment mark assists with initial orientation. Following that, the engagement sequence should follow the pattern: plug in bore, key aligns with keyway, pins and sockets engage, locking sleeve installed, final tightening to set face seal.
Retention
Once mated, the connector pair should be sufficiently restrained to avoid inadvertent disconnect due to stresses on the cable and connector. Retention mechanisms range from simple friction devices to screwed collars and latches.
8.5 COTS underwater connectors 185