Patent Description:
Loading arms transfer almost any liquid and compressed gas product to and from vessels. Transferring fluid between land and a vessel typically requires a safety device for quick and safe disconnection to prevent damage to personnel or property as well as to reduce the amount of product spillage.

The disclosures of <CIT> and <CIT> may be helpful for understanding the present invention. <CIT> concerns emergency disconnection systems for loading systems, in particular for loading/unloading arms, for example for the transfer of liquefied natural gas. <CIT> refers to an emergency separation device in a fluid cargo handling device.

The present invention refers to an emergency release system for a fluid transfer system according to claim <NUM>.

The invention further refers to a method using such an emergency release system according to claim <NUM>.

Advantageous embodiments may include features of depending claims.

<FIG> illustrates a schematic of a loading arm <NUM> including a riser <NUM>, an inboard arm <NUM>, and an outboard arm <NUM>. The outboard arm <NUM> includes an outboard swivel <NUM> that permits rotational movement of the arm <NUM> for connection with a vessel (e.g., a ship, a railcar, or a vehicle such as a truck) via a manifold <NUM> that mates with a manifold (not shown) on the vessel to facilitate the transfer of product to or from the vessel. The loading arm <NUM> is configured to operate within a defined operating envelope. That is, the loading arm <NUM> is configured such that the inboard arm <NUM> and the outboard arm <NUM> can only extend to a predetermined distance from the riser <NUM>. As shown in <FIG>, the loading arm <NUM> has a position monitoring system <NUM> that measures the position of the inboard arm <NUM> and the outboard loading arm <NUM>, and therefore the position of vessel, relative to the riser <NUM>.

With reference to <FIG>, the loading arm <NUM> also includes an emergency release system <NUM>. The emergency release system <NUM> is positioned at a location between the outboard swivel <NUM> and the manifold <NUM> to provide a mechanism that quickly and safely disconnects the loading arm <NUM> from a vessel with minimal product spillage due to relative movement between the loading arm <NUM> and the vessel (e.g., due to an emergency situation such as drift of the vessel, an example of which is described in detail below). The emergency release system <NUM> includes a first valve <NUM>, a second valve <NUM> that is aligned with the first valve <NUM> along axis A and that is selectively secured to the first valve <NUM> by an emergency release coupler <NUM>, and an actuator assembly <NUM> that has an actuator mechanism <NUM> (e.g., a scotch-yoke mechanism) and a double-stroke hydraulic cylinder <NUM> (e.g., a piston-cylinder assembly).

The first and the second valves <NUM>, <NUM> can be block valves (e.g., ball valves) or other types of valves that are suitable for closing off flow of fluid. As will be understood, each valve <NUM>, <NUM> is manipulatable between an open position permitting fluid flow through the emergency release system <NUM> and a closed position that inhibits fluid flow. With reference to <FIG>, <FIG>, <FIG>, and <FIG>, the first valve <NUM> has a flange <NUM> (best seen in <FIG>) that is sized and shaped to abut a flange <NUM> (best seen in <FIG>) on the second valve <NUM>. The first valve <NUM> also has a first valve actuator <NUM> (best seen in <FIG>) that is manipulatable (e.g., pivotable <NUM> degrees) to vary the first valve <NUM> between open and closed positions. The second valve <NUM> also has a second valve actuator <NUM> (best seen in <FIG>) that is manipulatable to vary the second valve <NUM> between open and closed positions (e.g., pivotable <NUM> degrees). Each of the first and the second valve actuators <NUM>, <NUM> is movable between a first position in which the respective first and valves <NUM>, <NUM> are open (see <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>), and a second position in which the respective first and the second valves <NUM>, <NUM> are closed (see <FIG>, <FIG>, <FIG>, <FIG>).

As shown in <FIG> and <FIG>, the coupler <NUM> includes a first clamp member <NUM> and a second clamp member <NUM> that are coupled together and define a breakaway coupler mechanism. The first clamp member <NUM> has a first end <NUM> and a second end <NUM> opposite the first end <NUM>, and an arcuately shape portion <NUM> that is disposed between the first and second ends <NUM>, <NUM> and that has an arcuate channel <NUM>. The second clamp member <NUM> has a first end <NUM> and a second end <NUM> opposite the first end <NUM>, and an arcuately shape portion <NUM> that is disposed between the first and second ends <NUM>, <NUM> and that has an arcuate channel <NUM>. The channels <NUM>, <NUM> are complementary to and engage the abutting flanges <NUM>, <NUM> of the first and second valves <NUM>, <NUM> to secure the valves <NUM>, <NUM> together when the emergency release system <NUM> is assembled.

As shown in <FIG> and <FIG>, the first ends <NUM>, <NUM> of the first and second clamp members <NUM>, <NUM> are pivotally coupled to a coupler bracket <NUM> that attaches to the first valve <NUM>. As shown, a first support <NUM> couples the first clamp member <NUM> to the coupler bracket <NUM> (e.g., via a threaded shaft or another attachment device), and a second support <NUM> couples the second clamp member <NUM> to the coupler bracket <NUM> (e.g., via a threaded shaft or another attachment device) opposite the first support <NUM>. The first support <NUM> includes a hinged connection <NUM> (e.g., a pinned connection) so that the first clamp member <NUM> can pivot or otherwise move relative to the second clamp member <NUM> and the coupler bracket <NUM>. Likewise, the second support <NUM> includes a hinged connection <NUM> (e.g., a pinned connection) so that the second clamp member <NUM> can pivot or otherwise move relative to the first clamp member <NUM> and the coupler bracket <NUM>. Fasteners <NUM>, <NUM> help secure the supports <NUM>, <NUM> to the coupler bracket.

As shown in <FIG>, the second end <NUM> of the second clamp member <NUM> includes gate brackets <NUM> that are attached to opposite sides of the clamp member <NUM> and that cooperate to define a channel <NUM>. Each gate bracket <NUM> also defines an arcuate pocket <NUM>. The second ends <NUM>, <NUM> of the first and second clamp members <NUM>, <NUM> are selectively coupled to each other by a gate <NUM>. The gate <NUM> has a first end <NUM> that is pivotally coupled to the second end <NUM> of the first clamp member <NUM>, and a second end <NUM> that is removably coupled to the second end <NUM> of the second clamp member <NUM> via the gate brackets <NUM>. As shown in <FIG>, the gate <NUM> includes lock elements <NUM> that are coupled to and movable relative to the second end <NUM> (e.g., rotatable or pivotable movement). The lock elements <NUM> engage the pockets <NUM> when the gate <NUM> is closed to secure the coupler <NUM> to the valves <NUM>, <NUM>. More specifically, the illustrated lock elements <NUM> pivot to clear the edges of the gate brackets <NUM>, and then pivot back to engage the pockets <NUM>. The complementary shapes and arrangement between the pockets <NUM> and the lock elements <NUM> define an over-center mechanism that holds the gate <NUM> in place and inhibits back-driving or release of the gate <NUM> from the gate brackets <NUM> absent a force applied to the gate <NUM>. With this arrangement, the gate <NUM> snaps down into the locked position (best seen in <FIG>) after the lock elements <NUM> engage the pockets <NUM> (one of the equilibrium states of the over-center mechanism; the other equilibrium state being the unlocked position shown in <FIG>) to hold the gate <NUM> in place and secure the clamp members <NUM>, <NUM> to each other at the second ends <NUM>, <NUM>.

Referring back to <FIG>, <FIG>, and <FIG>, the actuator mechanism <NUM> includes a dual rod <NUM> that has a first rod member <NUM> selectively coupled to a second rod member <NUM> by a rotatable latch <NUM>. The first rod member <NUM> includes a first pin or projection <NUM> that engages and rotates the first valve actuator <NUM> about an axis of rotation between the first and the second positions. Similarly, the second rod member <NUM> includes a second pin or projection <NUM> that engages and rotates the second valve actuator <NUM> about an axis of rotation between the first and the second positions. The axes of rotation are perpendicular to the page with respect to <FIG>.

The first rod member <NUM> is defined by plates <NUM> that are spaced apart to define a gap <NUM> (<FIG>) and that move together when the dual rod <NUM> is actuated. As shown in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, a safety plate <NUM> is attached to the first rod member <NUM> via spacers <NUM>, and a stop <NUM> is coupled to an end of the first rod member <NUM> and is engageable with a bracket <NUM> (e.g., coupled to the first valve <NUM>) to stop further movement of the actuator mechanism <NUM> in the downward direction (as viewed in the Figures).

The second rod member <NUM> has a latch receiver <NUM> (<FIG>) that is engageable by the latch <NUM>. As shown in <FIG>, the latch <NUM> has a first end <NUM> that is disposed in the gap <NUM> and that is pivotably secured to the first rod member <NUM> as described in detail below. With respect to <FIG>, the latch <NUM> has a second end <NUM> that defines a latch feature <NUM> (e.g., a projection that has is wider or thicker than a central portion <NUM> of the latch <NUM>) that selectively couples with the latch receiver <NUM>. The latch feature <NUM> engages the latch receiver <NUM> to secure the rod members <NUM>, <NUM> together.

The latch <NUM> is movable (pivotable or rotatable) from a latched position (in which the first and second rod members <NUM>, <NUM> are attached to each other) to an unlatched position (in which the first and second rod members <NUM>, <NUM> are detached from each other) by a latch actuator <NUM>.

The latch <NUM> is pivotally coupled to the first rod member <NUM> by a latch actuator <NUM>. As shown in <FIG>, the latch actuator <NUM> has an eccentric pin <NUM> including a post <NUM> with an axis B onto which the latch <NUM> is mounted for movement with the latch actuator <NUM> and an eccentric portion <NUM> coupled to the post <NUM>. The eccentric pin <NUM> is rotatable about an axis C, which is offset from the axis B (<FIG> and <NUM>), when the eccentric portion <NUM> engages a projection <NUM> on the first valve <NUM>, as will be discussed in greater detail below.

The second rod member <NUM> also includes a gate actuator <NUM>. As shown, the gate actuator <NUM> is wedge-shaped, although other shapes are possible. In general, the gate actuator <NUM> is shaped or positioned to engage the gate <NUM> and move the gate <NUM> to the unlocked position.

The actuator mechanism <NUM> includes a connected state and a disconnected state. With regard to <FIG>, <FIG>, <FIG> and <FIG>, in the connected state, the first and the second rod members <NUM>, <NUM> are coupled to one another via the latch <NUM>, which is aligned with both the first and the second rod members <NUM>, <NUM> along an axis D. With regard to <FIG>, <FIG>, and <FIG>, in the disconnected state, the latch <NUM> is disengaged from the latch feature <NUM> and the first and the second rod members <NUM>, <NUM> are separated from one another. As shown, the latch <NUM> is rotated out of alignment relative to the axis D (e.g., perpendicular to the axis D).

The cylinder <NUM> is configured to move the actuator mechanism <NUM> from the connected state to the disconnected state. Referring to <FIG>, the cylinder <NUM> is coupled to the second valve <NUM> by a bracket <NUM>. The cylinder <NUM> includes a housing <NUM> with a first end <NUM> that is coupled to the bracket <NUM>, and a second end <NUM> that extends from the bracket <NUM>. With respect to <FIG>, <FIG>, and <FIG>, the housing <NUM> also has a first piston <NUM>, a second piston <NUM>, a first port <NUM>, a second port <NUM>, and a third port <NUM>. The first piston <NUM> extends from the first end <NUM> of the housing <NUM> and is received by and secured to the second rod member <NUM>. The first and second pistons <NUM>, <NUM> are movable relative to the housing <NUM> and each other. That is, the pistons <NUM>, <NUM> of the cylinder <NUM> are movable among first, second, and third positions to selectively move the dual rod <NUM>. In the first position (shown in <FIG> and <FIG>), the first piston <NUM> extends beyond the housing <NUM> by a first distance <NUM>, and the second piston <NUM> is retained entirely within the housing (i.e., a distance between the second end <NUM> of the housing <NUM> and the second piston <NUM> is negligible). In the second position (shown in <FIG> and <FIG>), the first piston <NUM> extends beyond the housing <NUM> to a second distance <NUM>, and the second piston <NUM> is spaced apart from the second end <NUM> of the housing <NUM>. In the third position (shown in <FIG> and <FIG>), the first piston <NUM> extends beyond the housing <NUM> to a third distance <NUM>, and the second piston <NUM> remains spaced apart from the second end <NUM> of housing <NUM>.

The emergency release system <NUM> is configured to respond to a first shutdown condition (ESD1), a first shutdown condition override, and a second shutdown condition (ESD2). The first shutdown condition occurs if the position monitoring system <NUM> determines that the vessel has drifted away from the riser <NUM> by a first distance from the riser <NUM>. The first shutdown condition override occurs if the position monitoring system <NUM> determines that the vessel's drift has ceased, or the vessel has drifted back toward the riser <NUM> (i.e. drifted back to a distance between the initial distance and the first distance). The second shutdown condition occurs if the position monitoring system <NUM> determines that the vessel has drifted from the riser and reached a second distance from the riser <NUM> that is farther than the first distance and up to the predetermined distance that the loading arm <NUM> can extend. Additionally or alternatively, a user may actuate another mechanism (not shown) to achieve the first shutdown condition, the first shutdown condition override, or the second shutdown condition.

When the loading arm <NUM> is fluidly connected to the vessel and the vessel is at or near the initial distance from the riser <NUM> the emergency release system <NUM> is in a first state (<FIG> and <FIG>). In the first state, the first and the second valves <NUM>, <NUM> are open thereby allowing product to be transferred to or from the vessel. As shown in <FIG> and <FIG>, the first and the second clamp members <NUM>, <NUM> of the coupler <NUM> engage the abutting flanges <NUM>, <NUM> of the first and second valves <NUM>, <NUM>, and the gate <NUM> is secured between the second ends <NUM>, <NUM> of the first and the second clamp members <NUM>, <NUM>. When the gate <NUM> is secured between the first and the second clamp members <NUM>, <NUM>, the lock elements <NUM> are positioned within the pockets <NUM> of the second clamp member <NUM>. Additionally, the first and second pistons <NUM>, <NUM> are in their first position (<FIG> and <FIG>), the first and the second valve actuators <NUM>, <NUM> are in their first position (<FIG>, <FIG>, and <FIG>), and the actuator mechanism <NUM> is in the connected state (<FIG>, <FIG>, and <FIG>). In the first state, the safety plate <NUM> is adjacent the gate <NUM> of the release coupler <NUM> and the latch <NUM> of the actuator mechanism <NUM> is parallel to the axis D such that the first and second rod members <NUM>, <NUM> are coupled to one another.

Upon detecting the first shutdown condition, the emergency release system <NUM> moves from the first state (<FIG>, <FIG>) to a second state (<FIG>, <FIG>). To achieve the second state, the cylinder <NUM> applies a first stroke such that fluid (i.e., hydraulic fluid, pneumatic fluid, or the like) introduced through the first port <NUM> moves the first and second pistons <NUM>, <NUM> from the first position (<FIG> and <FIG>) to the second position (<FIG> and <FIG>). With respect to <FIG> and <FIG>, such movement of the first and second pistons <NUM>, <NUM> causes the second rod member <NUM> of the actuator mechanism <NUM> to translate the actuator mechanism <NUM> in a first direction <NUM> along the axis D (<FIG>). The movement of the actuator mechanism <NUM> causes the pins <NUM>, <NUM> of each of the respective first and second rod members <NUM>, <NUM> to engage the respective first and second valve actuators <NUM>, <NUM> thereby forcing the first and second valve actuators <NUM>, <NUM> to move from the first position (<FIG>, and <FIG>) to the second position (<FIG>, and <FIG>) to close the respective first and second valves <NUM>, <NUM>. In the second state, the actuator mechanism remains in the connected state, and therefore the latch <NUM> of the actuator mechanism <NUM> remains parallel to the axis D such that the first and second rod members <NUM>, <NUM> remain coupled to one another. Additionally, in the second state, at least a portion of the safety plate <NUM> remains adjacent the gate <NUM> of the coupler <NUM>, the gate <NUM> remains secured between the first and the second clamp members <NUM>, <NUM>, and the lock elements <NUM> remain positioned within the pockets <NUM> of the second clamp member <NUM>.

When in the second state, if the first shutdown condition override is detected, the emergency release system <NUM> moves from the second state (<FIG>, <FIG>) back to the first state (<FIG>, <FIG>). To do so, the cylinder <NUM> is actuated such that fluid (i.e., hydraulic fluid, pneumatic fluid, or the like) introduced through the third port <NUM> moves the first and second pistons <NUM>, <NUM> from the second position (<FIG> and <FIG>) back to the first position (<FIG>, and <FIG>). Such movement of the first and second pistons <NUM>, <NUM> causes the second rod member <NUM> of the actuator mechanism <NUM> to translate in a second direction <NUM> along the axis D (<FIG>). The movement of the actuator mechanism <NUM> causes the pins <NUM>, <NUM> of each of the first and second rod members <NUM>, <NUM> to engage the respective first and second valve actuators <NUM>, <NUM> thereby forcing the first and second valve actuators <NUM>, <NUM> to move from their second position to their first position to re-open the respective first and second valves <NUM>, <NUM>.

Alternatively, when in the second state, if the second shutdown condition is detected, the emergency release system <NUM> moves from the second state (<FIG> and <FIG>) to a third state (<FIG> and <FIG>). To achieve the third state, the cylinder <NUM> applies a second stroke such that fluid (i.e., hydraulic fluid, pneumatic fluid, or the like) introduced through the second port <NUM> moves the first piston <NUM> such that the first and second pistons <NUM>, <NUM> achieve the third position (<FIG>, <FIG>, and <FIG>). That is, movement of the first piston <NUM> because of the second stroke causes the second rod member <NUM> of the actuator mechanism <NUM> to continue to translate the actuator mechanism <NUM> in the first direction <NUM> along the axis D. Additionally, the safety plate <NUM> is displaced such that it is no longer adjacent to the gate <NUM> of the coupler <NUM>. Further, the continued movement of the actuator mechanism <NUM> causes the eccentric portion <NUM> of the eccentric pin <NUM> to engage the projection <NUM> on the first valve <NUM> thereby rotating the post <NUM> of the eccentric pin <NUM> about the axis C (<FIG>) and therefore, rotating the latch <NUM> therewith. Accordingly, with the rotation of the eccentric pin <NUM> and the latch <NUM>, the actuator mechanism <NUM> is forced into the disconnected state (<FIG>, and <FIG>), and therefore the first and second rod members <NUM>, <NUM> are no longer coupled to one another. With the latch <NUM> no longer coupling the first and second rod members <NUM>, <NUM>, the continued movement of the first and second pistons <NUM>, <NUM> and the second rod member <NUM> causes the gate actuator <NUM> to exert a force on the gate <NUM> thereby disengaging the second end <NUM> of the gate <NUM> from the second clamp member <NUM> and pivoting the gate <NUM> towards the first clamp member <NUM> (<FIG>). In particular, as the gate actuator <NUM> exerts a force on the gate <NUM>, the lock elements <NUM> of the gate <NUM> are biased from the pockets <NUM> until the lock elements are disengaged from the pockets <NUM> entirely. This results in the gate <NUM> popping out of the locked position, releasing the coupler <NUM>. Because the first and second clamp members <NUM>, <NUM> are no longer coupled to one another, the second valve <NUM> is no longer secured to the first valve <NUM> and therefore can disengage from the first valve <NUM>, leaving the coupler <NUM> behind supported by the support <NUM> on the first valve <NUM>.

As discussed in detail above, the emergency release system <NUM> permits closure of the valves without actuating the breakaway coupler <NUM> using the first stroke of a cylinder <NUM>, and permits separation of the dual rod <NUM> of the actuator mechanism <NUM> via the latch <NUM> using the a second stroke of the cylinder <NUM>.

Claim 1:
An emergency release system (<NUM>) for a fluid transfer system having a first valve (<NUM>) and a second valve (<NUM>) that is selectively fluidly coupled to the first valve, the emergency release system (<NUM>) comprising:
a breakaway coupler mechanism engageable with the first valve (<NUM>) and the second valve (<NUM>) to releasably couple the first valve (<NUM>) and the second valve (<NUM>) together, the breakaway coupler mechanism including
a first clamp member (<NUM>) engaged with the first and second valves (<NUM>, <NUM>), the first clamp member (<NUM>) having a first end (<NUM>) and a second end (<NUM>); and
a second clamp member (<NUM>) engaged with the first and second valves (<NUM>, <NUM>), the second clamp member (<NUM>) having a first end (<NUM>) coupled to the first end (<NUM>) of the first clamp member (<NUM>) and a second end (<NUM>), and
a gate (<NUM>), that is releasably coupled to the second end (<NUM>) of the first clamp member (<NUM>) and the second end (<NUM>) of the second clamp member (<NUM>) and that retains the breakaway coupler mechanism on the first valve (<NUM>) and the second valve (<NUM>) when the gate (<NUM>) is positioned in a locked position, in which the gate (<NUM>) is coupled to the second end (<NUM>) of the first clamp member (<NUM>) and the second end (<NUM>) of the second clamp member (<NUM>);
an actuator mechanism (<NUM>) engageable with the first valve (<NUM>) and the second valve (<NUM>), the actuator mechanism (<NUM>) including a gate actuator (<NUM>) and a safety plate (<NUM>), the gate actuator (<NUM>) configured to engage the gate (<NUM>) of the breakaway coupler mechanism as the actuator mechanism (<NUM>) moves from a connected state to a disconnected state, and the safety plate (<NUM>) being positioned adjacent to the gate (<NUM>) when the actuator mechanism (<NUM>) is in the connected state to prevent an inadvertent actuation of the gate (<NUM>) out of the locked position; and
a piston-cylinder assembly configured to engage the actuator mechanism (<NUM>) to selectively and simultaneously close the first and second valves (<NUM>, <NUM>), and to disengage the breakaway coupler mechanism from the first valve (<NUM>) and the second valve (<NUM>).