The present invention relates to a safety and arming unit for initiation of underwater charges, comprising: a housing; a detonator; an interrupter slidable within the housing from a first position in which a firing chain from the detonator to a charge is interrupted, to a second position, in which the firing chain is complete; a first member configured to cooperate with the housing and the interrupter to form a first interlock, wherein, upon the first member being in a first position, said interlock locks said interrupter in said first position, and upon the first member being in a second position, said interrupter is free to slide relative to said first member; a second member configured to cooperate with the housing and the interrupter to form a second interlock, mechanically independent of said first interlock, wherein, upon the second member being in a first position, the interlock locks said interrupter in said first position, and upon the second member being in a second position, said interrupter is free to slide relative to said second member; and a plurality of electrical switches arranged in series, switchable from a first configuration in which the detonator is electrically isolated from a remote initiation firing system, to a second configuration in which the detonator is in electrical communication with a remote initiation firing system; wherein, upon the first member being in the second position, and the second member being in the second position, the interrupter is slidable from the first position to the second position upon being subjected to an external water pressure of at least a predefined threshold value. Upon the interrupter being in the second position, the interrupter acts on the plurality of electrical switches to switch said plurality of switches to said second configuration.

The present invention relates to a safety and arming unit for initiation of underwater charges, comprising: a housing; a detonator; an interrupter slidable within the housing from a first position in which a firing chain from the detonator to a charge is interrupted, to a second position, in which the firing chain is complete; a first member configured to cooperate with the housing and the interrupter to form a first interlock, wherein, upon the first member being in a first position, said interlock locks said interrupter in said first position, and upon the first member being in a second position, said interrupter is free to slide relative to said first member; a second member configured to cooperate with the housing and the interrupter to form a second interlock, mechanically independent of said first interlock, wherein, upon the second member being in a first position, the interlock locks said interrupter in said first position, and upon the second member being in a second position, said interrupter is free to slide relative to said second member; and a plurality of electrical switches arranged in series, switchable from a first configuration in which the detonator is electrically isolated from a remote initiation firing system, to a second configuration in which the detonator is in electrical communication with a remote initiation firing system; wherein, upon the first member being in the second position, and the second member being in the second position, the interrupter is slidable from the first position to the second position upon being subjected to an external water pressure of at least a predefined threshold value. Upon the interrupter being in the second position, the interrupter acts on the plurality of electrical switches to switch said plurality of switches to said second configuration.

The present invention relates to a safety and arming unit for initiation of underwater charges, comprising: a housing; a detonator; an interrupter slidable within the housing from a first position in which a firing chain from the detonator to a charge is interrupted, to a second position, in which the firing chain is complete; a first member configured to cooperate with the housing and the interrupter to form a first interlock, wherein, upon the first member being in a first position, said interlock locks said interrupter in said first position, and upon the first member being in a second position, said interrupter is free to slide relative to said first member; a second member configured to cooperate with the housing and the interrupter to form a second interlock, mechanically independent of said first interlock, wherein, upon the second member being in a first position, the interlock locks said interrupter in said first position, and upon the second member being in a second position, said interrupter is free to slide relative to said second member; and a plurality of electrical switches arranged in series, switchable from a first configuration in which the detonator is electrically isolated from a remote initiation firing system, to a second configuration in which the detonator is in electrical communication with a remote initiation firing system; wherein, upon the first member being in the second position, and the second member being in the second position, the interrupter is slidable from the first position to the second position upon being subjected to an external water pressure of at least a predefined threshold value. Upon the interrupter being in the second position, the interrupter acts on the plurality of electrical switches to switch said plurality of switches to said second configuration.

The present invention relates to a safety and arming unit for initiation of underwater charges, comprising: a housing; a detonator; an interrupter slidable within the housing from a first position in which a firing chain from the detonator to a charge is interrupted, to a second position, in which the firing chain is complete; a first member configured to cooperate with the housing and the interrupter to form a first interlock, wherein, upon the first member being in a first position, said interlock locks said interrupter in said first position, and upon the first member being in a second position, said interrupter is free to slide relative to said first member; a second member configured to cooperate with the housing and the interrupter to form a second interlock, mechanically independent of said first interlock, wherein, upon the second member being in a first position, the interlock locks said interrupter in said first position, and upon the second member being in a second position, said interrupter is free to slide relative to said second member; and a plurality of electrical switches arranged in series, switchable from a first configuration in which the detonator is electrically isolated from a remote initiation firing system, to a second configuration in which the detonator is in electrical communication with a remote initiation firing system; wherein, upon the first member being in the second position, and the second member being in the second position, the interrupter is slidable from the first position to the second position upon being subjected to an external water pressure of at least a predefined threshold value. Upon the interrupter being in the second position, the interrupter acts on the plurality of electrical switches to switch said plurality of switches to said second configuration.

A method for monitoring a shock strut may comprise measuring a first shock strut pressure, measuring a first shock strut temperature, measuring a second shock strut pressure, measuring a second shock strut temperature, measuring a shock strut stroke, and determining a servicing condition of the shock strut based upon the first shock strut pressure, the first shock strut temperature, the second shock strut pressure, the second shock strut temperature, and the shock strut stroke and taking into account at least one of an absorption of a gas with a fluid and desorption of the gas with the fluid. In various embodiments, the method may further comprises measuring a third shock strut pressure, measuring a third shock strut temperature, wherein the servicing condition is further based upon the third shock strut pressure and the third shock strut temperature.

A method for monitoring a shock strut may comprise measuring a first shock strut pressure, measuring a first shock strut temperature, measuring a second shock strut pressure, measuring a second shock strut temperature, measuring a shock strut stroke, and determining a servicing condition of the shock strut based upon the first shock strut pressure, the first shock strut temperature, the second shock strut pressure, the second shock strut temperature, and the shock strut stroke and taking into account at least one of an absorption of a gas with a fluid and desorption of the gas with the fluid. In various embodiments, the method may further comprises measuring a third shock strut pressure, measuring a third shock strut temperature, wherein the servicing condition is further based upon the third shock strut pressure and the third shock strut temperature.

An energy transfer device (10) is provided that is capable of transferring the energy output from one pyrotechnic device (52) to another device (78) for initiating firing thereof. Device (10) comprises a device housing (12) in which a deformable device insert (14) is received. Device insert (14) comprises a central passageway (34) for transmitting the output from a pyrotechnic device (52), including energy, gasses, and/or solids, to another pyrotechnic device (78). The passageway (34) conducts the pyrotechnic device output to a precise location on the second pyrotechnic device (78) where firing is most effectively initiated. The energy transfer device (10) may be employed as a part of a tool (44) used in well completion operations.

A method for monitoring a shock strut may comprise measuring a first shock strut pressure, measuring a first shock strut temperature, measuring a second shock strut pressure, measuring a second shock strut temperature, measuring a shock strut stroke, and determining a servicing condition of the shock strut based upon the first shock strut pressure, the first shock strut temperature, the second shock strut pressure, the second shock strut temperature, and the shock strut stroke and taking into account at least one of an absorption of a gas with a fluid and desorption of the gas with the fluid.

In various embodiments, the method may further comprises measuring a third shock strut pressure, measuring a third shock strut temperature, wherein the servicing condition is further based upon the third shock strut pressure and the third shock strut temperature.

A method for monitoring a shock strut may comprise measuring a first shock strut pressure, measuring a first shock strut temperature, measuring a second shock strut pressure, measuring a second shock strut temperature, measuring a shock strut stroke, and determining a servicing condition of the shock strut based upon the first shock strut pressure, the first shock strut temperature, the second shock strut pressure, the second shock strut temperature, and the shock strut stroke and taking into account at least one of an absorption of a gas with a fluid and desorption of the gas with the fluid.

In various embodiments, the method may further comprises measuring a third shock strut pressure, measuring a third shock strut temperature, wherein the servicing condition is further based upon the third shock strut pressure and the third shock strut temperature.