Systems approach is used to determine the types of disturbances arising in a linear pipe component during its functioning and their effect causing disruption of leakproofness of composite pipes. A physical model of the permeation process where the pipe wall is considered to be a porous medium penetrated by parallel capillaries is proposed and the results of estimation of the permeability of the wall of a nonequilibrium spiral-screw wound composite pipe based on the leakproofness criterion are presented. The conceptual approaches to the solution of the problem of composite pipeline leakproofness are validated.