Abstract:
A connector for underwater connection of two fluid carrying conduits comprises initial engagement means to provide an initial engagement between a male component and a female receptacle. The final connection is made by operating a drive which reacts against the initial engagement means to move the component into a fully connected position. A number of sealing means may be provided to enable a pressure tight connection.

Description:
BACKGROUND 
   a. Field of the Invention 
   The present invention relates to a connector and in particular to a male/female connector for use in underwater applications. Such connectors are often referred to as “stab” connectors. 
   b. Related Art 
   It is conventional to use a remotely operated vehicle (ROV) to make a connection to a pipeline head for test purposes, For example, sending a pig along the pipeline to remove detritus or to confirm the diameter of the pipeline. Such a connection is made using a relatively small hose when compared to the pipelines used for transporting oil or gas. Typically, the ROV is used to introduce a male component into a female component (or receptacle) and then to force the component into the receptacle to provide a suitable, pressure tight connection. 
   SUMMARY OF THE INVENTION 
   According to the invention there is provided a connector comprising a male component and a female receptacle, wherein the male component is to be connected into the female receptacle to establish a fluid flow path between the male component and the female receptacle, the male component having means for making initial engagement with the receptacle and means for pulling itself fully into the receptacle by pushing against the initial engagement means. 
   The male component can be gripped and manipulated underwater by a ROV, and stabbed into the female receptacle sufficiently far to make initial engagement. Initial engagement can be achieved without the male component encountering the sealing means in the receptacle, and thus without encountering any substantial resistance to insertion. The ROV does not therefore have to exert significant axial force to the male component. 
   The male component is preferably at the end of a flexible hose and the female receptacle is part of a manifold assembly for a subsea pipeline. 
   The female receptacle may have an outwardly flared end to assist in guiding the male component into the receptacle, and the male component can have a rounded end to assist in guiding the male component into the receptacle. 
   The female receptacle preferably comprises a tubular body with a branch passage between its ends, and the male component has a central bore, a closed end and a lateral opening or openings at one point around its circumference, the lateral openings being adapted to communicate with the branch passage when the male and female components are fully engaged with one another. Sealing means are preferably provided between the male and female components in the fully engaged position. 
   The means for making initial engagement with the receptacle can comprise bayonet slots on the female receptacle, and radial projections on the male component (or vice versa). Alternatively the means for making initial engagement with the receptacle can comprise expanding collets on the male component which expand to lock behind ridges on the female receptacle. 
   The means for pulling the male component fully into the receptacle can comprise a rack and pinion arrangement working between a part of the male component which Is initially engaged with the female receptacle, and a part of the male component which incorporates a fluid flow passage and is to be driven fully into the receptacle. 
   In an alternative embodiment, the means for pulling the male component fully into the receptacle can comprise hydraulic rams working between a part of the male component which is initially engaged with the female receptacle, and a part of the male component which incorporates a fluid flow passage and is to be driven fully into the receptacle. 
   The invention also extends to a method of connecting a male component into a female receptacle in a subsea environment where the male component is to be connected into the female receptacle to establish a fluid flow path between the male component and the female receptacle, wherein part of the component is introduced into the female receptacle to engage initial engagement means, and then the male component drives Itself fully into the female receptacle by reacting against the initial engagement means. 
   The male component preferably carries a drive mechanism to drive itself fully into the receptacle. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a schematic depiction of a male component according to the present invention; 
       FIG. 2  shows a schematic depiction of a female receptacle for use with the component shown in  FIG. 1 ; 
       FIGS. 3 to 7  show the different stages by which a male component according to a first embodiment of the present invention is coupled to a receptacle as shown in  FIG. 2 ; 
       FIG. 8  Is a perspective view of a second embodiment of the invention, with the female receptacle shown mounted on a scrap section of pipeline; 
       FIG. 9  is a cross-section through a third embodiment of the invention, similar in principle to the second embodiment; and 
       FIG. 10  is a cross-section through the embodiment of  FIG. 10 , showing the component fully connected. 
   

   DETAILED DESCRIPTION 
     FIG. 1  shows a schematic depiction of a male component  10  according to a first embodiment of the present invention. The male component  10  comprises a cylindrical body  60  with a hollow bore  62 . A first end of the body  60  has a rounded nose  56  and the opposite end of the body has a component  48  for onward connection to a line or hose (not shown). First and second arms  64  and  66  are attached to either side of the cylindrical body  60  and first and second hydraulic actuators  44  and  46  are connected to the first and second arms  64  and  66  respectively and to the cylindrical body  60 . The rounded nose  56  projects beyond the first and second arms  64  and  66  so that the first and second arms do not interfere with leading end of the male component when this is inserted into a receptacle. 
   The first hydraulic actuator  44  is coupled to a first collet finger  40  and, similarly, the second hydraulic actuator  46  is coupled to a second collet finger  42 . Near to the first end of the body there is provided one or more apertures  54  that enable a fluid to flow from the hollow bore  62  into a receptacle (see below), or vice versa. The male component  10  comprises a first seal means  50  that is located in between the nose  56  and the apertures  54  and a second seal means  52  is located between the apertures  54  and the collet fingers  40 ,  42 . A handle  30  is provided to allow the component to be manipulated and maneuvered by a remotely operated vehicle (ROV). 
     FIG. 2  shows a schematic depiction of a female receptacle for use with the component shown in  FIG. 1 . The receptacle  20  is a T-component that comprise first and second pipeline apertures  22 ,  24  and a manifold component  26 . In use, a male component  10  will be connected to either the first or the second of the pipeline apertures  22 ,  24  to allow fluid to flow from a line or hose connected to the male component to the manifold, or vice versa. The receptacle further comprises first and second sealing lands  21 ,  23  and the pipeline apertures  22 ,  24  have first and second aperture engagement means  28 ,  29 . 
     FIGS. 3 to 7  show the different stages by which a male component according to a first embodiment of the present invention is coupled to a receptacle.  FIG. 3  shows the initial insertion of the component into a receptacle. The ROV is used to tilt the component relative to the receptacle such that the component is inserted into the receptacle at an angle. Once the nose  56  is received within the receptacle then the component  10  is oriented, through appropriate movement of the ROV, such that it is substantially coaxially aligned with the receptacle. (see  FIG. 4 ) with the first end of the component loosely received within the receptacle. 
     FIGS. 5 and 5   a  show the position of the component once the guide means  56  has passed the second receptacle engagement means  23  (the following description of the present invention is predicated on the insertion of the component into the second pipeline aperture  24 . It will be readily understood that the component could equally be inserted into the first pipeline aperture). The component is inserted up to this point through the action of the ROV on the component  FIG. 5   a  shows that the first collet finger  40  has been brought into close proximity with the second aperture engagement means  29  (although it is not shown in detail it will be understood that the second collet finger  42  has similarly been brought into close proximity with the second aperture engagement means  29 ). 
   At this stage, the ROV has completed its part in making the connection. 
   The next stage in the process of connecting the component to the receptacle is for the hydraulic cylinders  44 ,  46  to be activated to cause the collet fingers to engage with the second aperture engagement means  29  (see  FIG. 6 ). The action of the hydraulic cylinders cause the collet fingers to be deflected away from the body of the component to engage with the engagement surface of the second aperture engagement means  29  (see  FIG. 6   a ). This engagement of the collet fingers  40 ,  42  with the second aperture engagement means  29  the component to be secured to the receptacle. 
   The hydraulic cylinders  44 ,  46  are then activated to retract the pistons into the cylinders. Because the component is secured to the receptacle through the engagement of the collet fingers with the second aperture engagement means, the retraction of the hydraulic cylinders causes the body of the component to be drawn further into the receptacle, such that the first seal means  50  on the body  60  seal on the first sealing lands  21  and the second seal means  52  seal on the second sealing lands  23 . This positioning of the component causes the first and second pipeline apertures to be sealed such that any fluid flowing through from the manifold component  26  will flow through a line or hose (not shown) that is connected to the component  48 , and vice versa. 
     FIG. 8  shows an external view of a connector. In this view, and in  FIGS. 9 and 10 , components which have similar functions to those already described carry the same reference numeral indexed by  100 . 
   The female receptacle  120  has a stem  126  which is fixed in the wall of a pipeline  200 . It will be appreciated that only a part of the pipeline is shown in this figure. The receptacle has two ends  122  and  124 , and in  FIG. 8 , both ends are shown closed with sealing plugs  202 . The receptacle has two ends, although only one end will have a component connected to it at any one time. As the orientation of the pipeline  200  on the seabed can vary, one end may he inaccessible but there will always be one end which is accessible for the connection of the male component. 
   It will be seen that the receptacle  120  has bayonet slots  204  at both ends, and the sealing plugs  202  have radial lugs  206  which engage in the slots. The plugs also have handles  208  which are designed so that they can be gripped by an ROV. 
   The male component  110  has an annular ring bar  210  connected to the component by legs  212 . The positions of the legs and the points at which they connect to the body of the component are set to line up with the bayonet slots  204 . When the sealing plugs  202  have been extracted from the receptacle, the component  110  can be inserted by an ROV so that the legs  212  enter the slots  204  When fully inserted into the slots, a small rotation engages the legs in the ends of the slots. 
   Reference is now made to  FIGS. 9 and 10 .  FIG. 9  shows the position where the component  110  is initially engaged in the receptacle, with the legs  212  engaged in the bayonet slots  204 . At this point, the nose  156  of the component still lies behind the sealing lands  121 ,  123 . A drive mechanism, indicated schematically in  FIGS. 8 to 10 , consists of a sot of circumferential gear tooth shaped grooves  222  formed in the outer surface of the body  160 . A gearbox  224  mounted on the component  110  includes a pinion which engages in the grooves  222 , and which can be rotated to drive the body  160  to the right in  FIG. 9 , until it lakes up the position shown in  FIG. 10 , where the apertures  154  are in communication with the limb  126  of the receptacle. Seals (not shown in detail in  FIGS. 9 and 10 ). will be in place between the sealing lands  121  and  123  and the adjacent surfaces of the body  160 . 
     FIGS. 8 ,  9  and  10  clearly show the flared ends of the receptacle passages which will assist in locating the nose  16  of the component  110  in one or other of the passages. 
   To locate the component fully in the receptacle requires a significant amount of force to push (or “stab”) the component with its sealing rings  50  through the lands  121 ,  123 . The invention allows the initial insertion by ROV up to the point where significant force has to be exerted, and then the further insertion operation is carried out against the engagement of the component with the initial engagement means in the receptacle which provides a reaction surface against which the drive mechanism can operate. 
   It should be understood that although  FIGS. 8 to 10  indicate that the component comprises a male bayonet connecting means that can be connected to a female bayonet connecting means received on the receptacle, this situation may be reversed such that the component comprises a female bayonet connecting means that can be connected to a male bayonet connecting means received on the receptacle. 
   It will be readily understood that the connector may be modified or varied in a number of ways without departing from the teaching of the present invention. For example, the component may be provided with three (or more) hydraulic cylinders and their respective collet fingers to provide the engagement with the receptacle. Alternatives to the hydraulic cylinders may be used, for example electrical or pneumatic drive systems, although hydraulic systems are generally preferred in the subsea environment in which the present invention is to be used. A connector according to the present invention would be used in applications where conventionally that a pipeline has a diameter of 2-4 inches (50-100 mm) but it will be understood that the present invention is also suitable for use with pipelines of a larger or smaller diameter.