Abstract: A turnaround section for use with a two-pass crossflow heat exchanger. The turnaround section includes an arcuate housing and a plurality of arcuate fluid flow channels radially spaced within the housing, each arcuate channel having a first end configured, in use, to receive a first fluid from flow channels of a heat exchanger core and a second end to return the first fluid to return channels of the core. A plurality of separators are provided between each adjacent pair of arcuate channels to form further channels between the arcuate channels that extend and provide for flow of a second fluid in a plane transverse to the plane of the arcuate channels.

Abstract: An actuator release mechanism comprising a longitudinal member, e.g. a piston, which is moveable axially to permit or prevent axial movement of the lock bolt and hence deployment of the actuator. Movement of the piston is due to the force of the lock bolt, under a spring force, on the one hand, and to the position and force of a linkage assembly on the other hand. The linkage assembly comprises a first link fixed, at one end, e.g. by means of a piston lock pin, to the piston and fixed at a pivot point to a second link. The second link is fixed to a rotational drive means, here a rotary solenoid or stepper motor, so as to rotate about a centre of rotation.