Abstract: A steel service pipe is connected to a main by a tee. A flexible assembly is inserted through the open end of the pipe and through the tee into the main. The flexible assembly includes a section of lower stiffness and a ball and socket connection of even lower stiffness at its leading end. The ball is connected to a weight. The weight falls down on entering the tee and creates a turning moment on the assembly. A plastic pipe is inserted through the open end of the pipe over the assembly and is inserted through the tee into the main. The pipe has a corrugated leading end which is more flexible than the remainder of the pipe and has a tapered nose terminating in a cylindrical mouth which enters an aperture in a liner in the main.

Abstract: A self-centering suspension for use in supporting a vehicle or vehicles intended to travel in a pipeline includes a body and two sets of three wheels spaced apart along the length of the body. Each wheel is mounted on a lever arm biased by torsion springs against the inner surface of the pipeline. Each lever arm has a stub arm which is eccentrically arranged relatively to a rotary joint in the form of a pin, and the stub arm slidingly engages a circumferential groove in a ring. Each ring slides on the body. A set of three wheels are thus constrained to move inwards and outwards together.

Abstract: Apparatus for cutting a hole through a plastic liner in a gas or other main comprises a body forming module of a train of modules adapted to travel through the main. The body has a radially movable platform carrying a cutter. The platform has four cams engaging four cams pivotally mounted on tie-bars. Advancing movement of the platform pushes the cams outwardly causing support legs to move outwardly and to cause four slave legs carried by the support legs to engage the plastic liner. Further advancing movement of the platform causes the cutter to engage the liner and also holds the support legs in their advanced position as noses on the cams traverse the faces of the cams.

Abstract: The apparatus comprises a frame having a die pivotally connected to it at one end and anchorage means pivotally connected to it at the other end. The anchorage means carries a first roller. A second roller is adjustable transverse to the frame. A pipe pusher is integral with the die. The frame has adjustable legs to set the angle of the fame. A plastic pipe is pulled through the die and through the host pipe and is bent between the first roller, the second roller and the die. The frame fully contains the reactions arising owing to the bending of the pipe.

Abstract: A fluid flow control valve has a body enclosing a transfer passageway whose bounding surface is profiled to provide streamline flow conditions. The passageway is constricted by means of a piston-like valve moving transverse to the direction of fluid flow. A profiled shield protects the valve from direct impingement of fluid.

Abstract: A sealable pressure vessel 5 has a closure member 8 held on by means of a bayonet fixing member which is movable between two positions while retaining the mechanical linkage between the vessel 5 and the closure member 8 forming a container 1. The bayonet fixing comprises a vessel lug 19 which co-operates with a stepped slot 18 in a locking ring 9 secured to the closure member. In one position of the lug 19 in the slot 18 the closure member is sealed on the vessel and the container is closed to atmosphere while in another position the seal is broken and the container is open to atmosphere. The closure member 8 incorporates a sliding valve 29 which has a spring urged piston 32 carrying a locking pin 33 to lock the lug 19 within the slot 18 when the container is closed to atmosphere.

Abstract: A regulator installation, for controlling the pressure and/or flow of gas in a gas transmission or distribution system, comprising a compact module (10) having an inlet (32) and an outlet (33) adapted to be fitted in a pipeline (1) and containing within its outer shell (21,22,23) a removable assembly secured by locking means (29,30) and which carries the essential elements (2 to 9 and 43 to 45) of the regulator installation such that the gas flow path from the inlet (32) passes through the elements (2 to 5) to the outlet (33). The shell is provided with a removable cover (23) for gaining access to the control elements (6 to 9 and 43 to 45) and to the locking means (30) for enabling the assembly (31) to be removed for servicing and replacement.FIG. 2 is suggested as the drawing to accompany the Abstract.