A fluid flow closure device for a liquid natural gas tank, comprising: a fluid conduit attachable to an outlet nozzle of a liquid natural gas tank, the fluid conduit having a breakable region that is inclined to break upon application of a predetermined amount of force to the fluid conduit; a valve assembly entirely inside the fluid conduit, the valve assembly configured to transition between an open state that permits fluid flow in a distal direction and a closed state that inhibits fluid flow in a distal direction through the fluid conduit and wherein the valve assembly comprises; a valve retainer attached to an inside wall of the fluid conduit on a first side of the breakable region, the valve retainer having a support surface that extends from the first side of the breakable region to a second side of the breakable region; a seat positioned on a second and opposite side of the breakable region entirely inside the fluid conduit, wherein the seat is arranged to rotate about an eccentric pivot point along the seat, wherein the support surface of the valve retainer is arranged to support the seat in an orientation that enables fluid flow when the valve retainer is in a first state, and wherein the valve retainer is arranged to move away from the seat to a second state where the valve retainer no longer supports the seat such that the seat rotates to inhibit fluid flow in the fluid conduit when the valve retainer is in the second state; and characterized by: an actuator assembly arranged to cause the valve retainer to transition from the first state to the second state, wherein the actuator assembly includes a biased member that maintains the valve assembly in the open state until the actuator assembly is actuated and wherein the biased member is coupled to a piloted chamber. a fluid conduit attachable to an outlet nozzle of a liquid natural gas tank, the fluid conduit having a breakable region that is inclined to break upon application of a predetermined amount of force to the fluid conduit; a valve assembly entirely inside the fluid conduit, the valve assembly configured to transition between an open state that permits fluid flow in a distal direction and a closed state that inhibits fluid flow in a distal direction through the fluid conduit and wherein the valve assembly comprises; a valve retainer attached to an inside wall of the fluid conduit on a first side of the breakable region, the valve retainer having a support surface that extends from the first side of the breakable region to a second side of the breakable region; a seat positioned on a second and opposite side of the breakable region entirely inside the fluid conduit, wherein the seat is arranged to rotate about an eccentric pivot point along the seat, wherein the support surface of the valve retainer is arranged to support the seat in an orientation that enables fluid flow when the valve retainer is in a first state, and wherein the valve retainer is arranged to move away from the seat to a second state where the valve retainer no longer supports the seat such that the seat rotates to inhibit fluid flow in the fluid conduit when the valve retainer is in the second state; and characterized by: an actuator assembly arranged to cause the valve retainer to transition from the first state to the second state, wherein the actuator assembly includes a biased member that maintains the valve assembly in the open state until the actuator assembly is actuated and wherein the biased member is coupled to a piloted chamber. a valve retainer attached to an inside wall of the fluid conduit on a first side of the breakable region, the valve retainer having a support surface that extends from the first side of the breakable region to a second side of the breakable region; a seat positioned on a second and opposite side of the breakable region entirely inside the fluid conduit, wherein the seat is arranged to rotate about an eccentric pivot point along the seat, wherein the support surface of the valve retainer is arranged to support the seat in an orientation that enables fluid flow when the valve retainer is in a first state, and wherein the valve retainer is arranged to move away from the seat to a second state where the valve retainer no longer supports the seat such that the seat rotates to inhibit fluid flow in the fluid conduit when the valve retainer is in the second state; and characterized by: an actuator assembly arranged to cause the valve retainer to transition from the first state to the second state, wherein the actuator assembly includes a biased member that maintains the valve assembly in the open state until the actuator assembly is actuated and wherein the biased member is coupled to a piloted chamber.