Abstract: A method of installing a socket with a socket contact on an underwater plug with a plug contact is provided so as to establish conductive contact between the socket contact and the plug contact. The socket is disconnectably attached to a recoverable fluid exchange unit and the socket engages with the plug to establish the conductive contact between the socket contact and plug contact. The recoverable fluid exchange unit is then operated to substantially replace a first fluid within the socket with a second fluid from the recoverable fluid exchange unit.

Abstract: A substantially underwater system comprises a plurality of retrievable substantially autonomous subsea modules (12, 13, 17, 18) and switchgear (15, 16, 21a . . . h). A host facility (6) and the modules are connected in series so as to form a circuit, the host facility providing power to all of the modules. Operation of the switchgear electrically isolates a module or a plurality of serially adjacent modules so that the module or modules can be removed without cutting off the power supply to any of the remaining modules of the system. Module based parts of the switchgear (21a . . . h) only or a combination of module based parts (21a . . . h) and host facility based parts (15, 16) of the switchgear are actuated depending on which module or modules are isolated and removed.

Abstract: To install a modular seabed processing system (1) on a seabed, a monopile foundation (3) is first lowered down and driven into the seabed. A docking unit (4) is lowered towards the installed foundation (3) so that a mating clamp system (6) mounted on the docking unit is aligned with a spigot (5) on the foundation. The clamp system then clamps the spigot to fix the docking unit onto the foundation. Flowlines (2) and an electrical power connector plug (18) are connected to the docking unit. A first retrievable substantially autonomous module (8) is lowered and connected to the docking unit (4) by a multi-bored connector (10, 11) and the plug (18) on the docking unit is engaged by a corresponding socket (17) on the module. Isolation valves (14, 16) in the docking unit and module are opened so that the module (8) is able to act on fluid received from the flowlines (2) via the multi-bored connector (10, 11).

Abstract: A retrievable fluid separation module (2) for a seabed processing system to which flow lines are connected includes one portion (60) of a multi-ported valve isolation connector (5) and a separator chamber (6) for separating a plurality of fluids from a received fluid mixture. The separator chamber has an inlet flow line (12) for the received fluid mixture and an outlet flow line (15, 16) for each separated fluid. The flow lines are connected to the one portion of the connector (5) which selectively isolates the module from or connects it to the flow lines by means of a second complementary portion (61) of the multi-ported valve isolation connector with which the first portion is adapted to engage. There may be a modulating valve (25) in at least one outlet flow line (16) for controlling flow therethrough and a control actuator (63) for controlling the or each modulating valve.

Abstract: A two-part connector (1) is provided for use in connecting and disconnecting fluid carrying conduits. The connector comprises lower and upper parts (2, 3) each having four fluid carrying duct (15) therethrough, and a valve member (17) for each duct. Each duct in the lower part (2) is aligned with its respective duct in the upper part (3) when the two connector parts are connected together. The connector has clamps (24) for retaining the lower and upper parts (2, 3) together in sealing engagement. The clamps are mounted on the upper connector part (3) and are pivotable thereabout. Hydraulic pistons are used to move the clamps, the clamps being located in a first position pivoted away from the connector whilst the lower and upper parts (2, 3) are being aligned relative to each other.

Abstract: A valve actuator (1) is provided which comprises an actuator stem (4) extending from a housing (2) which contains a sleeve (17). The actuator stem (4) is driven so as to cause the sleeve to compress a stack of springs (22) within the housing until bolts (25) engage the sleeve, locking the springs in a compressed state. At the same time an armature (28) on the actuator stem is attracted to an electromagnet (29) within the housing. The actuator stem can then be driven to open or close a valve in a controlled manner without first compressing or releasing the springs. In an emergency, the electromagnet is switched off, releasing the armature thus unlocking the stack of springs. The released springs push the piston which partially retracts the actuator stem into the housing causing the valve to be closed.