Abstract: A device for manufacturing a welded connection of tubular components of plastics material. The ends of the components to be connected are axially aligned and held to abut with the end surfaces. The ends of the tubular components can be heated by a foldable heating device which surrounds the tubular components. A support device is arranged in the interior of the tubular components. A heating device which can be fastened on a frame in a determined position is provided for each pipe diameter dimensioned to be welded. Electrical contacts are provided for each heating device. A welding program of a program control predetermined for each dimension can be selected by the contacts when the heating device is placed on the frame.

Abstract: A heating arrangement (2) embracing tubular parts (1a, 1b) of plastic material which have to be joined by welding, comprises electrically heatable jaws (26).A bladder (50) expandable by compressed air is arranged inside the tubular parts (1a, b), which includes a centrally arranged tensile part (56) such as, for instance, cable for the purpose of limiting the length. The air pressure in the bladder is higher than the pressure generated by the material when melting, this for the purpose of producing an adequate welding pressure.

Abstract: A shut-off valve assembly includes a housing which has a spherical plug arranged in a chamber. The housing has an internal thread into which a support element for a sealing member is screwed. On the outer end face of the support element is supported a flange bushing by means of a retaining nut. The pitches of the internal thread and of an external thread for the retaining nut are directed in opposite directions, so that the support element cannot be loosened when the retaining nut is unscrewed.

Abstract: An actuating device operated by a pressure medium, such as compressed air, acting within a housing, can be secured to a valve by a mounting member attached to the valve. The actuating device includes a first piston guided in a cylinder part positioned on one side of the center part of the housing. A toothed rack is attached to the first piston and is in meshed engagement with a pinion shaft located within the center part of the housing. The pinion shaft is connected by a coupling part to the valve shaft. The same actuating device can be used for a larger valve by placing a second piston in another cylinder part on the opposite side of the center part from the first piston with a toothed rack attached to the second piston and in meshed engagement with the pinion shaft. The first and second pistons act in opposite directions and double the torque acting on the pinion shaft as compared to the torque delivered by the first piston.

Abstract: In a board holding device for a board (1) provided with a circuit, in which the board (1) is inserted in the groove (3, 3') of an elongate frame part (2, 2'), the mechanical and electrical connection between the board (1) and the frame part (2, 2') is produced by a solder connection which is carried out by means of solder ducts (4, 4') filled with a solder. The board holding device can be supplemented in a simple manner by cover plates to give a complete screening or resonance casing which has good electrical and mechanical properties. The holding device is very suitable for automated manufacture.