Abstract: A piping system comprising an inner pipe for carrying fluid and an outer pipe forming a thermal insulation jacket for the inner pipe. The pipe line is formed in sections which are joined together by means of flange members in a manner so as to provide longitudinal compression of the inner pipe such that when the cryogenic fluid is run through the inner pipe and the walls of this pipe contract with the reduction in temperature, minimum stress is placed on the pipe with such contraction, thereby avoiding damage thereto or the formation of leaks therein. Each section is bent to form angulated legs, the bent or elbow portions operating to take most of the precompression. The precompression is achieved in a simple yet highly effective manner by providing a flange on the outer pipe having a circle of fastening means for use in clamping flanges on the ends of the inner pipe sections to each other and to the outer pipe flange, at the same time compressing the inner pipe.

Abstract: A plurality of actuator members are mounted along the surface of a roadway in the path of vehicular traffic, so as to be actuated as the wheels of vehicles pass thereover. Beneath each actuator is a chamber formed of resilient material, one of the walls of this chamber being deflected inwardly in response to an associated actuator. The chambers are filled with gas and connected to each other in series by means of a suitable valving arrangement. The gas contained within the chambers, which is preferably air, is compressed by virtue of the actuation of the chamber, gas being fed from chamber to chamber such that successively higher gas compression levels will be reached at succeeding chamber stages in the chain. To facilitate the actuation of the higher level compression stages the actuation surfaces thereof are made to have a decreased area so that greater force per unit area can be provided for a given weight vehicle.