Abstract: An inflatable plug within a fragile streamlined cover attached to a rigid lance tube is pushed through a leakage hole to plug it on an upstream end by being inflated with pressurized fluid conducted through the lance tube to rupture the fragile cover and position the plug against the wall sealingly covering the upstream end of the hole.

Abstract: A fluid flow control device includes a support brace fixably mounted in a uid flow tube. An actuator rod is slidably supported by the support brace. A plurality of conical washers are mounted in sliding engagement on the rod between a stop mechanism on the rod and the support brace. The conical washers are arranged along the rod in an abutting configuration such that adjacent conical washers abut alternately at an apex or base of the conical washers. In operation, the rod is moved so that a compressive force is applied to the conical washers. In this way, the conical washers expand in a radial fashion to reduce the fluid flow area between the device and the tube.

Abstract: A throttle or fluid control valve uses at least one compressible multi-wave asher as a fluid control element. The apertures formed by the multi-wave washer are short and of low aspect ratio when the valve is fully open to limit pressure drop across the valve, thus substantially preventing cavitation and flow-related noise to high flow velocities. As the valve is closed, the aspect ratio of the apertures increases but surfaces of the apertures remain angled to each other to provide noise cancellation and damping. Several multi-wave washers spaced by sliders are preferably used to further limit pressure drop in any stage and to form a serpentine path in the general direction of flow to provide further noise cancellation and damping. The sliders also enhance the self-purging action of the valve structure. A closure structure is also provided for assuring full closure of the valve.

Abstract: An E-R hydraulic control valve that has two or more surfaces that can be moved relatively to one another to adjust a flow orifice size while maintaining a control voltage gradient across the E-R fluid and to seat one surface against the other to shut off fluid flow. Combining movable mechanical fluid flow elements with E-R fluid control allows initial tuning of the valve to a particular application by mechanical restriction of an orifice, and E-R operating control of the fluid. Seating the mechanical surfaces provides a fail-safe shut-down mode.

Abstract: A variable capacity centrifugal pump capable of directly varying capacity, r output, in response to existing back pressure. The pump comprises a axially movable shroud having female grooves in fluid tight communication with male impeller vanes. The shroud has a top face surface in fluid communication with a control cavity which in turn is in fluid communication with pump back pressure.

Abstract: A variable breadth centrifugal pump arrangement includes two intermeshing peller sections that are mounted to a common pump shaft so that one of the impeller sections is axially moveable relative to the other impeller section. The impeller sections are rotationally interconnected by a torque transmitting member in the form of a bellows element, which may comprise an axially resilient metal tube formed with a plurality of pleats or a plurality of radially spaced pleated metal tubes that are separated by elastomeric material. Another form of torque transmitting bellows element comprises a plurality of dish-shaped element connected together at their central and peripheral edge portions.

Abstract: A hydraulic machine comprising a rotor concentrically supported in a fluid hamber of the housing wherein upper and lower annular fluid spaces defined between the rotor and housing include upper cavity regions formed radially adjacent the rotor axis and lower cavity regions declined radially therefrom. Fluid supply ports in the upper cavity regions of the annular spaces permit flow of a relatively low density pressurized fluid into the annular spaces to control the level of pumped fluid therein and seal elements span the upper regions of the annular spaces for maintaining pressure differentials between the annular spaces and fluid passages of the housing. Clearance gaps, defined by circumferential edges of the rotor and adjacent surfaces of the fluid chamber, radially bound the lower cavity regions of the annular spaces for limiting the flow of pumped fluid into and out of the annular spaces.

Abstract: Netting constructed from strong elongated tubular elements encloses optic fiber signal lines. Such netting is anchored at spaced locations underwater adjacent to a dock to establish a protection zone for sea vessels within the zone from terrorist threats to be delivered underwater by penetration or attempted penetration of the netting which may also block damaging impact inflicted on sea vessels within the zone by missiles. If a missile however penetrates the netting for impacting the sea vessel, the location of such netting penetration is then indicated through the signal lines so as to enable rapid threat response.