Abstract: A rigid metal framework includes parallel u-shaped guides which are spaced apart and lined with a resilient material for supporting the edges of a solar absorber or core, which guides are connected with separate transverse members at their opposite ends together with intermediate cross-supports to increase the rigidity of the framework and a clamp in one of the housings to secure a manifold of a solar absorber, thereby allowing expansion and contraction of the core to occur in the guides, thereby providing support of the core without creating stress in the absorber. The framework can be fixed to the installation site but allows the absorber to float in a controlled manner within the framework without damage, as thermal conditions change. In addition, the framework design allows glazing (transparent covers) to be placed over the absorber, enhancing the efficiency of the resulting collector unit.

Abstract: A self-tapping coupling for plastic piping has a hollow cylindrical section with external self-tapping threads and a sealing member with an O-ring whereby the sealing member is retained in the end of the plastic pipe by the threads cut by the cylindrical section when the latter is inserted in the end of the pipe with rotation.

Abstract: A modular plastic heat exchanger includes at least one thermal exchange element having parallel outer and inner plastic sheets separated by a plurality of parallel ribs extending between said sheets and connected thereto to form a plurality of channels generally rectangular in cross-section with a plastic insulating foam sized to be co-extensive with said outer sheet and secured to the exterior surface of said outer sheet, and a pair of cylindrical manifolds, each having a large central flow tube oriented normal to such channels in said thermal exchange element and fixedly secured to said thermal exchange element on opposite edges thereof, each of said manifolds being operably connected to fluidly communicate said channels to its flow tube at the ends of said channels, whereby the inner sheet can be tightly faced against a cylindrical member to be thermally controlled and temperature controlled fluids can be passed from one manifold to the other to control the temperature of the member.