to transfer a fluid at high service temperature and pressure without the limitations of rigid tubing , a flexible tube is provided with a plurality of generally concentric tubular layers for transferring fluids . the innermost layers define a fluid flow path and provide insulation without pressure containment whereas the outermost layers provide fluid containment and resist pressure exerted by the fluid flowing through the tube . by utilizing a plurality of layers of different materials selected to have specific characteristics , the flexible tube operates at a service temperature and pressure providing a high level of energy transfer .