Abstract: The present invention provides a method and apparatus for adapting standard threaded fasteners for use with a standard stud tensioner. An adapter has internal and external threads. The internal threads mate with the external thread of the stud to be tensioned. The external threads of the adapter engage the internal threads of a fastening nut having slots on the top thereof for engagement with a turning wrench of the tensioner. The adapter has a central threaded bore on the top portion thereof which is adapted to threadably engage the puller bar of a tensioning apparatus. The stud is elongated by actuation of the tensioner, via the puller bar, lifting the adapter as the stud is tensioned. When appropriate strain is achieved on the stud, the fastening nut is turned down to a fastened position and the stud then can be relaxed.

Abstract: A power driven stud tensioner device which connects to an engaging member integral with or connected to a stud to be placed in tension after which a nut on the stud is tightened. The device for placing the stud in tension is a cam actuated clamping assembly having a plurality of layers wherein motion of one component translates into a different motion in another component. The device includes a helically slotted actuating sleeve which receives cam pins passing through an axially slotted stationary ring which are then received in one of two inner camming rings which are axially shifted by the pins in response to rotation of the sleeve. Rotation of the actuating sleeve, which is driven externally by a power drive including a gear assembly connected to the sleeve, will cause the camming rings to move into and out of engagement with cam followers formed on, or attached to, a four segmented clamp which is thus moved into, and out of, locking engagement with the engaging member.

Abstract: A stud drive tool for threading and unthreading a stud in a head of a vessel, such as a reactor, including a base plate adapted to rest on a flange on the head of vessel. The tool includes means for inserting the stud into a hole in the vessel and to thread and unthread the stud therein.The base plate effectively absorbs any counter-torque produced by the turning of the stud while it is being driven because handles, which serve as reaction rods and guides, are rotatable and rest against the outside of the flange.The tool for threading and unthreading the stud means includes a moveable jaw clamp insertable into a threaded hole in the top of the stud and moveable into a position to clasp the stud and pneumatic means in which the pressure is manually regulated to equalize the weight of the stud as it is being threaded into or unthreaded out of the vessel, and an air motor which turns the stud.

Abstract: An integral tensioner assembly mountable on a stud selectively to insert and remove the stud as from a pressure vessel or the like, or to place the stud under tension so that a holding nut can be freely turned on the stud to tighten or loosen the stud connection to the pressure vessel. The assembly includes a housing which carries a plurality of nuts operable in selective pairs. Each of the pairs of nuts has a separate nut turning mechanism which is carried by the housing.The integral stud assembly is fastened to the vessel to operate on the stud without the need of extra bulky temporary connection systems.

Abstract: A stud tensioner device which connects to a engaging member integral with or connected to a stud to be placed in tension to permit a nut on the stud to be tightened. The stud is usually in a high pressure application such as a pipe line or various types of pressure vessel. The device for connecting to the engaging member is a cam actuating and clamping assembly having multilayers and partaking of translatory motion wherein the motion of one component translates into a different motion in another component. The device includes an actuating sleeve helically slotted to receive cam pins which pass through an axially slotted stationary ring to be received in one of two inner camming rings which are axially shifted by the pins responsive to rotation of the sleeve. Rotation of the actuating sleeve will cause the camming rings to move into and out of engagement with cam followers formed on or attached to a four segment clamp which is thus moved into and out of locking engagement with the engaging member.

Abstract: A bolt tensioner has a cylinder and piston assembly whose piston is connected to a puller bar on which is mounted a socket formed with segments for connecting the puller bar to a bolt to be tensioned, and the inner surface of a sleeve reciprocable on said puller bar and the outer surfaces of said segments have coactive circumferential ridges and grooves with beveled sides to actuate and hold the segments into cooperative relation to the bolt and means to actuate the segments out of said cooperative relation upon movement of the sleeve into lower and upper positions, respectively. A reciprocable power operated apparatus connected to the upper end of the sleeve reciprocates the sleeve.