An expansion joint for a waveguide line comprises two telescoping tubular members and a bellows connecting the two members to allow relative movement therebetween while maintaining a uniform continuous electrical surface through the joint with the capability of supporting either positive or negative pressure with respect to atmospheric pressure.

A fitting is be quickly mounted to smooth wall tubes, said fitting having an entry for the tube end, an annular seal within said body, and a ram element within said body which is translated to sealing and release positions by a quick operating actuating means. Means are provided to reduce wear between the ram element and the actuating means. The fitting may be provided as a dead head or may be coupled to a second conduit for conveying fluids therethrough; and the fitting may be adapted for high pressure fluid conveyance by including within the body a split collet member cooperating with said seal to enhance sealing action under high pressure.

A pipe jack for installation in pipe lines adjacent to a piece of equipment, such as, for example, a valve or pump, in order to remove said equipment when it needs to be serviced or replaced. End parts of the jack are threadably connected together by a center member or sleeve. The threads are left and right hand threads so that, as the center member or sleeve is rotated in one direction, the end parts are moved inwardly so that the jack contracts or is shortened and, when the sleeve is rotated in the opposite direction, the end parts are moved outwardly away from each other to lengthen the jack. Thus, a piece of equipment adjacent the jack may be removed when the jack is contracted and, when the serviced or replacement piece of equipment has been replaced, the jack is expanded to tightly and sealingly secure the piece of equipment in place. The inner ends of the end parts are provided with fingers which interlock with each other, but which are adapted to slide longitudinally relative to each other to prevent the end parts from rotating relative to each other when the jack is being shortened or lengthened. A piece of laminated, corrugated flexible tubing or sleeve is placed over the fingers and welded, or otherwise suitably secured to the end parts outwardly of the roots or outer ends of the fingers, to provide a sealing connection between the end parts.