Abstract: A heat exchanger assembly for use with concentrating solar collectors of the type employing an elongated conduit for transporting a heat exchange fluid, the heat exchanger being positioned within an opening in the upper surface of the conduit and operating to transfer heat to the heat exchange fluid. The heat exchanger includes a plurality of stacked heat conducting heat exchanger plates having grooves oriented to form flow passage extending in the direction of fluid flow. The heat exchanger includes an alignment feature to insure proper alignment of the flow passages with the direction of heat exchange fluid flow. The grooved heat exchange plates may be fabricated by stamping from a sheet of heat conducting material to facilitate manufacturing of the heat exchanger. In another embodiment, the plates are positioned normal to the fluid flow direction with openings in the plates serving to form flow channels.

Abstract: A valve operator for controlling the movement of a valve member carried by a rotatable valve shaft of a valve. The valve operator limits the movement of the valve member between a predetermined opened position and a closed position, the valve operator being adjustable without complete disassembly of the same to adjust the closing position of the member when necessary without affecting the overall amount of movement of the valve member as limit stops are operatively positioned on an operating shaft or stem of the valve operator with one of the stops being adjustable to axially move the operating shaft or stem and, thus, simultaneously adjust the other stop. Additionally, the valve operator is provided with coupling means for coupling the same to the rotatable shaft of the valve member, the coupling means being so arranged as to include a coupling sleeve which may be easily replaced by another coupling sleeve to accommodate the valve operator for valves having different diameter valve shafts.