IMPROVED PIPE SECTION AND COUPLING ABSTRACT OF THE DISCLOSURE A pipe section is provided having means on the end thereof for use in assembly in the section in series in a pipe system. The pipe section has a compressible seal mounted in a groove in the end. A frusto-conical shaped seal surface is formed on the interior of the female end adjacent the threads. The apex angle of the frusto-conical sealing surface, the lead of the screw threads and the allowable diametric clearance of the seal means are related to provide a pipe joint which allows 360 degrees or a full turn of relative rotation between coupled sections while providing an effective seal therebetween. The compressibility of the seal, the apex angle of the sealing surface and lead of the screw are also related to provide a makeup torque for interconnecting the sections which is in the range which can be applied by an ordinary worker by hand to the section without tools. Indicia means are provided on the exterior of the pipe to indicate allowable interengagernent of the sections for effective sealing.