Patent Publication Number: US-9422696-B2

Title: Fluid connectors

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a U.S. National Stage Application of International Application No. PCT/GB2011/050810 filed Apr. 21, 2011, which claims the benefit of and priority to Great Britain Patent Application No. 1006898.9 filed Apr. 26, 2010. The entire disclosures of International Application No. PCT/GB2011/050810 and Great Britain Patent Application No. 1006898.9 are incorporated herein by reference. 
     This invention relates to fluid connectors for connecting a supply pipe to a fitting. The invention has particular, but not exclusive application for connecting a mixing valve to supply pipes for hot and cold water. 
     Conventional mixing valve design requires two pipes to extrude through the wall surface which are then attached to the mixing valve using compression nuts and olives. These usually have pipe concealing plates to hide the hole for the pipe and the edges of cut tiles. 
     The mixing valve is usually attached to the wall surface using a mounting or backplate via screws into wall plugs (depending on wall type). This has the disadvantage that the olives compress onto the pipes preventing future removal of the nuts, olives and pipe concealing plates. A further disadvantage is that the mixing valve has a large footprint. 
     The present invention has been made from a consideration of the foregoing and seeks to mitigate the aforementioned disadvantages. 
     According to a first aspect of the invention, there is provided a mixing valve assembly comprising a mixing valve having inlets for supply pipes for hot and cold water, a mounting plate for securing to a support surface such that the supply pipes extend through the mounting plate for reception in the inlets, wherein the mixing valve is releasably connectable to the mounting plate, and the assembly further comprises means co-operable with the inlets to secure releasably the supply pipes and wherein the pipe securing means and mounting plate can be removed from the supply pipes when the mixing valve is detached from the mounting plate. 
     The securing means is positionable on the supply pipes and co-operable with the inlets in response to reception in the inlets to grip and secure releasably the supply pipes in the inlets. 
     The securing means may comprise sleeves that are a sliding fit on the pipes and are compressed by engagement with the inlets to secure the pipes when fitting the valve. The sleeves are released when the valve is detached and can be removed from the pipes together with the mounting plate. 
     Preferably, the mounting plate conceals the pipe entry holes and the sleeves are slidable over the ends of the pipes so as to extend into the inlets when the valve is attached to the mounting plate. This allows the valve, sleeves and mounting plate to be removed completely at a later date and provides a smaller foot print for the valve. 
     Preferably, the sleeves are made of a material such as plastics and are resilient so as to return towards their original shape when the valve is disconnected from the mounting plate and release the pipes so that the sleeves and mounting plate can be removed from the pipes. The sleeves may be integral with the mounting plate or separate from the mounting plate. 
     In some forms, each sleeve is separate from the mounting plate and comprises a cylindrical body with an external flange at one end that may locate against the mounting plate and the body is received in and co-operates with the inlet to secure the pipe and prevent the pipe being pushed back through the opening in the mounting plate. 
     In other forms, each sleeve is integral with the mounting plate and comprises a cylindrical body that is received in and co-operates with the inlet to secure the pipe and prevent the pipe being pushed back through the opening in the mounting plate. 
     In one arrangement, the inlets are provided within the valve body. Preferably, the inlets are a push fit on the pipes and a fluid-tight seal is provided between the pipes and the valve body within the inlets. For example sealing members such as O-rings may be located within the inlets to seal against the outer or inner surface of the pipes. Preferably, the valve body is releasably secured to the mounting plate and conceals the mounting plate. For example, the valve body may be secured by means of a retainer, such as a locking pin or grub screw that may be inserted through an opening in the valve body to engage the mounting plate to secure releasably the valve body to the mounting plate. Alternatively, the retainer may comprise a detent such as a tongue, clip or lug on one of the valve body and mounting plate that engages the other to secure releasably the valve body to the mounting plate. The detent may engage with a snap action to provide a positive indication that the valve body has been secured to the mounting plate. 
     In another arrangement, the inlets are provided by inlet connectors. Preferably, the inlet connectors fit over the pipes and a fluid tight seal is provided between the pipes and the inlet connectors within the inlets. For example sealing members such as O-rings may be located within the inlets to seal against the outer or inner surface of the pipes. 
     In one embodiment, the inlet connectors are releasably attached to the mounting plate by engagement of screw threads on the mounting plate and inlet connectors. In this embodiment, the inlet connectors are preferably rotatable relative to the valve body to attach and detach the valve body. Alternatively or additionally, the valve body may be detachable from the inlet connectors. 
     In another embodiment, the inlet connectors are a push-fit on the pipes and releasably secured to the mounting plate. For example, the inlet connectors may be secured by means of retainers, such as clamps. The valve body may be detachable from the inlet connectors. 
     Preferably, a fluid tight seal is provided between the pipes and the mounting plate. For example the pipes may pass through openings in the mounting plate and sealing members such as O-rings may be located within the openings to seal against the pipes. 
     The seals between the pipes and the mounting plate preferably provide a back-up to the seals between the pipes and the inlets. As a result, any fluid that leaks past the seals within the inlets is prevented from passing back along the pipes into the support surface where it may remain undetected for a period of time sufficient to cause damage to the support surface or surrounding structure. 
     Preferably the inlets are in the form of bores in the valve body or in the inlet connectors. The bores may be of uniform cross-section, i.e. cylindrical, producing a substantially constant gripping force as the sleeves move further into the bores. Alternatively, the bores may increase in cross-section towards the outer end, i.e. taper, producing an increased gripping force as the sleeves move further into the bores. 
     According to a second aspect of the invention, there is provided a method of connecting supply pipes for hot and cold water to inlets of a mixing valve, the method comprising the steps of providing a mounting plate with holes for passage of the pipes, attaching the mounting plate to a support surface so that the pipes pass through the holes and project from gripping means positionable on the projecting ends of the pipes, inserting the projecting ends of the pipes into inlets of the mixing valve so that the gripping means co-operates with the inlets to secure the pipes, and connecting the mixing valve to the mounting plate. 
     Preferably, the gripping means comprises sleeves that are slidable on projecting ends of the pipes and co-operate with the inlets to compress the sleeves to grip the pipes. The compression force is released when the inlets are detached from the pipes allowing the sleeves to be slid off the pipes and the mounting plate removed. The sleeves may be separate from or integral with the mounting plate. 
     According to a third aspect of the invention, there is provided a fitting for connection to a water supply pipe, wherein the fitting has an inlet co-operable with means positioned on the pipe to grip and secure releasably the pipe when the pipe and gripping means are received in the inlet. 
     Preferably, the gripping means comprises a sleeve that is slidable on the pipe and co-operates with the inlet to compress the sleeve to grip the pipe. The compression force is released when the inlet is detached from the pipe allowing the sleeve to be slid off the pipe. The inlet may comprise a cylindrical bore or a tapered bore. 
     Preferably, the fitting is connectable to a mounting plate through which the pipe extends and the fitting is connectable to the mounting plate. The mounting plate can be attached to a support surface such as a wall to conceal entry of the pipe through an opening in the support surface. 
     Removal of the sleeve allows the mounting plate to be detached from the support surface and slid off the pipe. The sleeve may be separate from or integral with the mounting plate. The sleeve may take any of the forms described previously. 
     The fitting may be a mixing valve having separate inlets for supply pipes for hot and cold water and separate gripping means to secure each pipe. 
     According to a fourth aspect of the invention, there is provided a mounting plate for a mixing valve, the mounting plate being adapted for securing to a support surface and having openings adapted for passage of supply pipes for hot water and cold water in a fluid-tight manner for connection to a mixing valve. 
     Preferably, the mounting plate is provided with gripping means positionable on the supply pipes passing through the openings and co-operable with inlets of the mixing valve to grip and secure releasably the supply pipes in the inlets for connecting the supply pipes to the mixing valve. 
     The gripping means may comprise sleeves separate from or integral with the mounting plate as described previously. The sleeves are preferably compressed within the inlets to grip and secure the pipes. The sleeves may take any of the forms described previously. 
     Preferably, the openings are provided with seal members such as O-rings for sealing engagement with the supply pipes passing through the openings. 
     Preferably, the mounting plate is adapted for attaching a mixing valve having inlets for connection to the supply pipes passing through the openings. The mixing valve may be releasably attached to the mounting plate. The inlets may be provided by a body of a mixing valve or by inlet connectors connected to the body. The body may be secured by any of the means described previously. 
     According to a fifth aspect of the invention, there is provided a system for mounting a mixing valve on a support surface to connect inlets on the mixing valve to supply pipes projecting from the support surface, the system comprising a mounting plate for securing to the support surface so that the supply pipes pass through openings in the mounting plate, and retainers configured to fit over the supply pipes and co-operate, in use, with the inlets of a mixing valve attached to the mounting plate to grip the supply pipes. 
     Preferably, the mounting plate is adapted for releasably attaching the mixing valve such that the mounting plate and retainers can be removed from the supply pipes when the mixing valve has been detached. 
     Preferably, the supply pipes and retainers are received in the inlets and the retainers are compressed to grip the supply pipes. The retainer may be separate from or integral with the mounting plate. 
     The retainers may comprise sleeves through which the supply pipes extend. The sleeves may take any of the forms described previously. 
    
    
     
       The invention will now be described in more detail by way of example only with reference to the accompanying drawings in which: 
         FIG. 1  shows a prior art installation of a mixing valve; 
         FIG. 2  is a longitudinal section through a mixing valve installation according to a first embodiment of the invention; 
         FIG. 3  is a perspective view of the mounting plate of the installation of  FIG. 2 ; 
         FIG. 4  shows the mounting plate of  FIG. 3  and the inlet pipes for connection to inlets of the mixing valve of  FIG. 2 ; 
         FIG. 5  shows the mounting plate and inlet pipes of  FIG. 4  with sleeves for retaining the inlet pipes; 
         FIG. 6  shows the mounting plate, inlet pipes and sleeves of  FIG. 5  ready for receiving the mixing valve of  FIG. 2 ; 
         FIG. 7  shows the installed position of the mixing valve of  FIG. 2  ready for inserting the locking pin to secure the mixing valve to the mounting plate; 
         FIG. 8  is a longitudinal section showing a modification to the mixing valve of  FIG. 2 ; 
         FIG. 9  is a longitudinal section showing a modification to the mounting plate of  FIG. 3 ; 
         FIG. 10  is perspective view of a mixing valve installation according to a second embodiment of the invention; 
         FIG. 11  is a perspective view of the mounting plate of the installation of  FIG. 10 ; 
         FIG. 12  is a perspective view, partly cut away, showing the mounting plate of  FIG. 11  and the inlet pipes for connection to the mixing valve of  FIG. 10 ; 
         FIG. 13  is a perspective view, partly cut away, showing the mounting plate and inlet pipes of  FIG. 12  with sleeves for retaining the inlet pipes; 
         FIG. 14  is a sectional view, partly cut away, showing inlet connectors for the mixing valve of  FIG. 10  connected to the mounting plate of  FIG. 13 ; 
         FIG. 15  is a perspective view, partly cut away, of the inlet connections for installation of the mixing valve of  FIG. 10 ; 
         FIG. 16  is a perspective view showing a modification to the mounting plate of  FIG. 11 ; 
         FIG. 17  shows a detail of the one of the clamps shown in  FIG. 16 ; 
         FIG. 18  shows a detail of the engagement between the clamp of  FIG. 17  and an inlet connector; 
         FIG. 19  is a sectional view, showing the engagement between the clamp and inlet connector of  FIG. 18 ; and 
         FIG. 20  is a perspective view, partly cut away, showing the mixing valve connected to the mounting plate of  FIG. 16   
     
    
    
     Referring first to  FIG. 1  of the drawings, a typical prior art installation of a mixing valve  1  shown. The mixing valve  1  has a cylindrical body  3  housing a control valve (not shown) coupled to a rotatable control knob  5  at the front end for starting/stopping water flow and selecting water temperature. The control valve may be thermostatic or non-thermostatic. The body  3  has a pair of inlet connectors  7  for connection to inlet pipes (not shown) for hot and cold water and an outlet connector  9  for connection to a flexible hose (not shown) or supply pipe (not shown) to deliver mixed water to an ablutionary fitting such as a shower handset (not shown) or shower head (not shown). 
     The rear end of the body  3  fits over and is releasably connected to a mounting plate (not shown) that is secured to a support surface (not shown) such as a wall. Holes (not shown) in the support surface for passage of the inlet pipes are covered by concealing plates  11  that fit over the inlet pipes and the inlet connectors  7  are secured to the inlet pipes by compression nuts  13  that compress olives (not shown) mounted on the inlet pipes to provide a fluid tight seal. When the mixing valve  1  is removed, the concealing plates  11  and compression nuts  13  are retained by the tight fit of the olives on the inlet pipes. This can complicate replacing the mixing valve if the compression nuts  13  do not fit the inlet connectors of the new mixing valve. 
     Referring now to  FIGS. 2 to 7  of the drawings, there is shown installation of a mixing valve  101  according to a first embodiment of the invention. The mixing valve  101  is adapted for mounting on a wall or similar support surface  102  by means of a mounting plate  103 . 
     The mounting plate  103  has the shape of an ellipse with two apertures  105 ,  107  for passage of water supply pipes  109 ,  111  for connecting the mixing valve  101  to supplies of hot and cold water. It will be understood the shape of the mounting plate  103  could be other than an ellipse. The mounting plate  103  is secured to the wall by screws or similar fixings (not shown) that pass through holes  113 ,  115  in the mounting plate. It will be understood that the number and position of the screw holes may be altered. The mounting plate  103  may be plastic or metal. The mounting plate may be used as a template to mark the positions on the wall  102  for entry of the pipes  109 ,  111  and for securing the plate  103  to the wall  102 . 
     The mixing valve  101  has a body  117  housing a control valve  118  for mixing hot and cold water for delivery to an outlet  119  on the underside of the valve body  117 . A rotary control knob  121  at the front end of the valve body  117  is operable to control the temperature and flow rate of the water delivered to the outlet  119 . 
     The rear end of the body valve  117  is provided with a countersink  123  having the shape of an ellipse to receive the mounting plate  103 . The depth of the countersink is such that the rear end of the valve body  117  locates against the wall  102  to conceal the mounting plate  103 . It will be understood that the elliptical shape of the mounting plate  103  and countersink  123  in the valve body  117  is not limiting and that other shapes may be employed. Matching shapes for the mounting plate and countersink may assist location and alignment of the valve body on the mounting plate for installation purposes but it will be understood, this is also not limiting and the mounting plate and countersink may have non-matching shapes. 
     The valve body  117  is releasably secured to the mounting plate  103  by means of a locking pin  125  ( FIG. 7 ). The locking pin  125  is inserted through a hole  127  in the underside of the valve body  117  adjacent to the outlet  119  and through aligned holes  131  in two spaced flanges  129  on the mounting plate  103  to engage a threaded bore (not shown) in the valve body  117 . The locking pin  125  has a head  133  with a recessed drive formation  135  that requires a tool with a matching formation to engage/disengage the locking pin  125  to prevent inadvertent or unauthorised removal of the valve body  117 . Any other suitable means for releasably securing the valve body  117  to the mounting plate  103  may be employed such as a grub screw. 
     The rear end of the body  117  is also provided with a pair of axially extending inlets  137 ,  139  to receive the supply pipes  109 ,  111 . The inlets  137 ,  139  are similar and one inlet will now be described in more detail with reference to  FIG. 2 , it being understood that the description applies to the other inlet. 
     The inlet  137  comprises a stepped bore having an inner end portion  141  and an outer end portion  143 . The outer end portion  143  terminates in a shoulder  145  leading to the inner end portion  141 . The inner end portion  141  is cylindrical and has an internal groove in which an elastomeric O-ring  147  is received. The outer end portion  143  is tapered to increase in diameter from the shoulder  145  towards the rear end of the valve body  117 . 
     The inner end portions  141  of the inlets  137 ,  139  communicate with inlet chambers  149 ,  151  for delivery of hot and cold water to the control valve. In this embodiment, the control valve  118  is a shuttle valve having a valve shuttle  153  axially movable between hot and cold seats for controlling the relative proportions of hot and cold water delivered to a mixing chamber  155  communicating with the outlet  119 . Also in this embodiment, a thermostat  157  responsive to the water temperature in the mixing chamber  155  is operable to adjust the position of the shuttle  153  to maintain a selected water temperature constant. Shuttle valves of this type are well known to those skilled in the art and are not further described herein. It will be understood that the control valve may be of any suitable type and may be thermostatic or non-thermostatic as well known to those skilled in the art. 
     During installation, the mounting plate  103  is fitted over the supply pipes  109 ,  111  and secured to the wall so that the pipes  109 ,  111  project from the mounting plate  103  ( FIG. 4 ). If necessary, the projecting length of the pipes  109 ,  111  can be reduced to allow fitment of the valve body  117 . Sleeves  159 ,  161  are then fitted over the ends of the supply pipes  109 ,  111  projecting through the holes  105 ,  107  in the mounting plate  103  and slid along the pipes  109 ,  111  to seat in counterbores  163 ,  165  in the mounting plate  103  concentric with the holes  105 ,  107 . 
     The sleeves  159 ,  161  are similar and have a cylindrical body sized to slide over the pipes. A plurality of slots  167  extend axially from one end of the body towards the other end. The body has an external collar  169  at one end that is split in the circumferential direction by the slots  167  and an external flange  171  at the other end. The slots  167  terminate before the flange  171 . The flange  171  is of increased diameter relative to the collar  169 . The sleeves  159 ,  161  may be made of plastics or other materials such as elastomers or metals. 
     Also during installation, the supply pipes  109 ,  111  are provided with filters  173 ,  175 . The filters  173 ,  175  are similar and one filter will now be described in more detail with reference to  FIG. 2 , it being understood that the description applies to the other filter. 
     The filter  173  has a tubular sieve portion  177  that is a clearance fit in the end of the supply pipe  109  and a head portion  179  that is a close fit in the end of the supply pipe  109 . The outer end of the head portion  179  is enlarged to be a radial tight fit in the inner bore portion  141 . The tubular sieve portion  177  provides a large surface area for water to flow through so that there is a reduced risk of the filter  173  becoming blocked to restrict flow. The filters  173 ,  175  fit in the end of the supply pipes  109 ,  111  and can be removed for cleaning and/or replacement. 
     With the sleeves  159 ,  161  and filters  173 ,  175  in place, the valve body  117  is presented to the mounting plate  103  to align the inlets  137 ,  139  with the supply pipes  109 ,  111  ( FIG. 6 ). The valve body  117  is then moved towards the mounting plate  103  to connect the supply pipes  109 ,  111  to the inlets  137 ,  139 . Each connection is similar and one connection will now be described in more detail with reference to  FIG. 2 , it being understood that the description applies to the other connection. 
     The supply pipe  109  is received in the outer end portion  143  of the inlet  137  as the valve body  117  is pushed towards the mounting plate  103 . The sleeve  159  is seated against the mounting plate  103  and is compressed radially inwards to grip the supply pipe  109  by engagement with the outer end portion  143  of the inlet  137  to prevent the supply pipe  109  being pushed back into the wall. As a result, the axial relationship between the sleeve  159  and the supply pipe  109  does not change as the valve body  117  is pushed towards the mounting plate  103  and the gripping force increases as the sleeve  159  extends further into the inlet  137  due to the taper of the outer end portion  143 . In this way, the supply pipe  109  is firmly secured and retained within the inlet  137 . 
     In the installed position ( FIG. 2 ), the flange  171  at the end of the sleeve  159  is located between the mounting plate  103  and the valve body  117  and the end of the supply pipe  109  is received in the inner end portion  141  of the inlet  137  where the O-ring  147  provides a fluid-tight seal with the outer surface of the supply pipe  109  in the inner end portion  141 . It will be understood that the supply pipe  111  is likewise firmly secured and retained in a fluid-tight manner within the other inlet  139  by a similar arrangement. 
     The trimmed length of the supply pipes  109 ,  111  should be sufficient to ensure a fluid-tight seal with the O-rings  147  in the installed position of the mixing valve  101 . Variations in the trimmed length of the supply pipes  109 ,  111  can be accommodated by the inner end portion  141  of the inlets  137 ,  139  as shown in  FIG. 2  where the left hand side shows a minimum trimmed length and the right hand side shows a maximum trimmed length 
     With the mixing valve  101  in position on the mounting plate  103 , the locking pin  125  is inserted to secure the valve body  117  to the mounting plate and prevent the mixing valve  101  being detached from the mounting plate  103  ( FIG. 7 ). When it is desired to remove the mixing valve  101 , the locking pin  125  is removed and the valve  101  can be detached from the mounting plate  103 . In a modification (not shown), the locking pin  125  may be replaced by any other means for releasably securing the mixing valve  101  to mounting plate  103 . For example, the mounting plate  103  and valve body  117  may have co-operating formations which engage when the valve body  117  is fitted on the mounting plate  103  to secure the mixing valve  101  and which can be released to allow the valve body  117  to be removed from the mounting plate  103  when it is desired to detach the mixing valve  101 . Suitable co-operating formations may comprise a projection on the mounting plate  103  such as a tongue, lug or clip that engages a recess within the valve body  117  when the valve body  117  is located on the mounting plate  103  to secure the mixing valve and that can be disengaged from the recess by inserting a tool through an opening in the valve body  117  to release the valve body  117  for detaching the valve  101  from the mounting plate  103 . The formations may engage automatically as the valve body  117  is fitted on the mounting plate  103 , for example with a snap or spring action that may provide an indication to the fitter that the valve body  117  has been correctly located and secured. 
     The compression of the sleeves  159 ,  161  is reduced as the valve body  117  is displaced away from the mounting plate  103  reducing the grip on the supply pipes  109 ,  111 . When the valve  101  is detached from the mounting plate  103 , the sleeves  159 ,  161  can be slid-off the pipes  109 ,  111  allowing the mounting plate  103  to be removed by releasing the screws attaching the mounting plate  103  to the wall  102  and leave the ends of the supply pipes  109 ,  111  projecting from the wall for mounting another mixing valve. By the use of sleeves  159 ,  161  to secure and retain the supply pipes  109 ,  111  in the inlets  137 ,  139  when the mixing valve  101  is installed, removal and replacement of the mixing valve  101  is facilitated. In a modification (not shown), the sleeves  159 ,  161  may be integral with the mounting plate  103 . 
     Referring now to  FIG. 8  of the drawings, there is shown a modification to the mixing valve of  FIGS. 2 to 7  in which like reference numerals are used to indicate corresponding parts. 
     As shown, the inlet  137  is modified so that the outer end portion  143  is cylindrical with a chamfer  143   a  at the entry end to assist initial compression of the sleeve  159 . With this arrangement, the gripping force is substantially unchanged as the valve body  117  is pushed towards the mounting plate  103  so that the sleeve  159  extends further into the inlet  137  and the supply pipe  109  is firmly secured within the inlet  137 . The outer end portion of the inlet  139  is likewise cylindrical with a chamfer at the outer end and the supply pipe  111  is secured in the inlet  139  in similar manner. In other respects, the construction and operation of the mixing valve and mounting plate is the same as the embodiment of  FIGS. 2 to 7  and may include any of the modifications thereof. 
     Referring now to  FIG. 9  of the drawings, there is shown a modification to the mounting plate of  FIGS. 2 to 7  in which like reference numerals are used to indicate corresponding parts. 
     As shown, the mounting plate  103  is provided on the underside with two bosses  181 ,  183  concentric with the holes  105 ,  107 . The bosses  181 ,  183  are received in the openings in the support surface for passage of the supply pipes  109 ,  111  so that the mounting plate  103  locates against the support surface. The supply pipes  109 ,  111  extend through the bosses  181 ,  183  and are sealed relative to the mounting plate  103  by O-rings  185 ,  187  that are located in internal annular grooves within the bosses  181 ,  183 . These O-rings  185 ,  187  provide second or back-up seals to the first or main seals provided by the O-rings  147  within the inlets  137 ,  139 . As a result, any fluid that leaks past the O-rings  147  is prevented from passing back along the supply pipes  109 ,  111  through the openings in the support surface where such leakage may remain concealed from view for a period of time until evidence of the leak is apparent. Instead, the fluid is confined to work its way between the mounting plate  103  and the valve body  117  to appear at the rear edge of valve body  117  on the outside of the support surface so as to be visible and allow appropriate remedial action to be taken before appreciable damage is caused within the support surface and the adjacent structure of the building. In other respects, the construction and operation of this mixing valve and mounting plate is the same as the embodiment of  FIGS. 2 to 7  and may include any of the modifications thereof such as shown in  FIG. 8 . 
     Referring now to  FIGS. 10 to 14  of the drawings, there is shown installation of a mixing valve  201  according to a second embodiment of the invention. The mixing valve  201  is adapted for mounting on a wall or similar support surface (not shown) by means of a mounting plate  203 . 
     The mounting plate  203  is rectangular with two apertures  205 ,  207  for passage of water supply pipes  209 ,  211  for connecting the mixing valve  201  to supplies of hot and cold water. The apertures  205 ,  207  are defined by cylindrical bosses  213 ,  215  on one side of the mounting plate  203 . Each boss  213 ,  215  is similar and one boss will now be described in more detail with reference to  FIG. 12 , it being understood that the description applies to the other boss. 
     The boss  213  has a stepped bore  217  having a first bore portion  219  that terminates in a shoulder  221  leading to a second bore portion  223  of reduced diameter. The second bore portion  223  has an internal annular groove  225  in which an O-ring (not shown) is located to provide a fluid tight seal with the outer surface of the supply pipe  209 . The supply pipe  209  is a clearance fit in the first bore portion  219  and defines an annular gap  227  therewith. The first bore portion  219  is provided with an internal screw thread  229  intermediate the ends. 
     The mounting plate  203  is secured to the wall by screws or similar fixings (not shown) that pass through holes  231 ,  233 ,  235 ,  237  in the mounting plate. The holes  235 ,  237  are elongated in directions normal to one another to allow limited adjustment to be made to the position of the mounting plate  203  on the wall. When secured, the bosses  213 ,  215  extend behind the mounting plate  203  into holes or openings (not shown) provided in the wall for entry of the supply pipes  209 ,  211 . The mounting plate  203  extends over and conceals the holes or openings. The mounting plate  203  may be plastic or metal. It will be understood that the mounting plate  203  may be rectangular as shown or any other shape for concealing the holes or openings in the wall, for example round, elliptical or the like. 
     The mixing valve  201  has a cylindrical body  239  housing a control valve (not shown) for mixing hot and cold water for delivery to an outlet  241  at one end of the valve body  239 . Rotary control members  243 ,  245  provided at the ends of the valve body  239  are operable by means of levers  247 ,  249  to control the flow rate and temperature respectively of the water delivered to the outlet  241 . The control valve may be of any suitable type and may be thermostatic or non-thermostatic as well known to those skilled in the art. 
     Between the ends of the valve body  239  there are two inlet connectors  251 ,  253  that extend normal to the longitudinal axis of the valve body for attaching the mixing valve  201  to the mounting plate  203  and for connecting the mixing valve  201  to the supply pipes  209 ,  211 . Each inlet connector  251 ,  253  is similar and one connector will now be described with reference to  FIGS. 10 and 14 , it being understood that the description applies to the other connector. 
     The inlet connector  251  has a first end portion  255  that is fixed relative to the valve body  239  and a second end portion  257  that is rotatable relative to the first end portion  255  about the longitudinal axis of the connector  251 . An O-ring  259  provides a fluid tight seal between telescopically engaged parts of the end portions  255 ,  257  and a collar  261  axially retains the second end portion  257  relative to the first end portion  255 . 
     The second end portion  257  has an external screw thread  263  towards the free end for engagement with the internal screw thread  229  of the boss  213 . The second end portion  257  has a through bore with an internal annular groove  265  in a short cylindrical portion between the ends in which an O-ring (not shown) is located to provide a fluid tight seal with the outer surface of the supply pipe  209 . The cylindrical bore portion leads to an outer end portion  267  that is tapered to increase in diameter towards the free end of the connector  251 . In a modification (not shown), the outer end portion  267  may be cylindrical with a chamfer at the outer end similar to the modification of the previous embodiment shown in  FIG. 8 . 
     During installation, the mounting plate  203  is fitted over the supply pipes  209 ,  211  and secured to the wall so that the pipes  209 ,  211  project from the mounting plate  203  ( FIG. 12 ). If necessary the projecting length of the pipes  209 ,  211  can be reduced to allow fitment of the inlet connectors  251 ,  253 . Sleeves  269 ,  271  are then fitted over the ends of the supply pipes  209 ,  211  and slid along the pipes  209 ,  211  into the annular gap  227  between the pipes  209 ,  211  and the bosses  213 ,  215 . The sleeves  269 ,  271  are similar to the sleeves  159 ,  161  of the previous embodiment with a cylindrical body having an external flange  273  at one end and an external collar  275  at the other end that is split in the circumferential direction by a plurality of slots (not shown) that extend in the axial direction towards and terminate before the flange  273 . The flange  273  is passed over the end of the supply pipe first when fitting the sleeves  269 ,  271 . 
     Also during installation, the supply pipes  209 ,  211  are provided with filters  277 ,  279  similar to the filters  165 ,  167  of the previous embodiment with a tubular sieve portion  281  that is a clearance fit in the end of the supply pipe and a head portion  283  that is a close fit in the end of the supply pipe. The outer end of the head portion  283  is enlarged to be a radial tight fit in the inlet connector. As in the previous embodiment, the filters  277 ,  279  fit in the end of the supply pipes  209 ,  211  and are removable for cleaning, replacement. 
     With the sleeves  269 ,  271  and filters  277 ,  279  in place, the mixing valve  201  is presented to the mounting plate  203  to align the inlet connectors  251 ,  253  with the supply pipes  209 ,  211 . The inlet connectors  251 ,  253  are then attached to the mounting plate  203  to connect the supply pipes  209 ,  211  to the mixing valve  201 . Each connection is similar and one connection will now be described in more detail with reference to  FIG. 14 , it being understood that the description applies to the other connection. 
     The rotatable end portion  257  of the connector  251  is inserted into the gap  227  between the supply pipe  209  and boss  213  until the screw threads  229 ,  263  of the boss  213  and connector  251  engage whereupon the end portion  257  is rotated to secure the connector  251  to the mounting plate  203 . The flange  273  of the sleeve  269  is located between the abutment shoulder  221  and the end of the inlet connector  251 . The split collar  275  of the sleeve  269  is received in the tapered bore portion  267  of the inlet connector  251  and co-operates with the tapered bore portion  267  as the end portion  257  of the connector  251  is screwed into the boss  213  causing the sleeve  269  to be compressed radially inwards to grip the supply pipe  209  and prevent the supply pipe  209  being pushed back into the wall. 
     As a result, the axial relationship between the sleeve  269  and the supply pipe  209  does not change as inlet connector  251  is screwed into the mounting plate  203  and the gripping force increases as the sleeve  269  extends further into the inlet connector  251  due to the taper of the bore portion  267 . In this way, the supply pipe  209  is firmly secured and retained within the inlet connector  251 . In the installed position, the O-ring located in the groove  265  of the inlet connector  251  provides a first or main fluid-tight seal with the outer surface of the supply pipe  209  and the O-ring located in the groove  225  of the boss  213  provides a second or back-up fluid-tight seal with the outer surface of the supply pipe  209 . 
     If any fluid leaks past the main seal, the back-up seal prevents fluid passing back along the supply pipe  209  through the holes in the support surface where such leakage may not visible. Instead any leakage of fluid will tend to work its way forwards between the mounting plate and the connector to appear on the outside of the support surface so as to be visible and allow appropriate remedial action to be taken before appreciable damage is caused within the wall and the adjacent structure of the building. It will be understood that the supply pipe  211  is likewise firmly secured and retained in a fluid-tight manner within the other inlet by a similar arrangement. 
     When it is desired to remove the mixing valve  201 , the inlet connectors  251 ,  253  can be unscrewed from the bosses  213 ,  215  and the valve  201  detached from the mounting plate  203 . The compression of the sleeves  269 ,  271  is reduced as the connectors  251 ,  253  are unscrewed. 
     When the valve  201  is detached from the mounting plate  203 , the sleeves  269 ,  271  can be slid-off the pipes  209 ,  211  allowing the mounting plate  203  to be removed by releasing the screws attaching the mounting plate  203  to the wall and leave the ends of the supply pipes  209 ,  211  projecting from the wall for mounting another mixing valve. By the use of sleeves to secure and retain the supply pipes  209 ,  211  in place when the mixing valve  201  is installed, removal and replacement of the mixing valve  201  is facilitated. 
       FIG. 15  shows a modification to the above described method, in which the outer end portions  257  of the inlet connectors  251 ,  253  are detached from the valve and screwed into the mounting plate  203  to secure the pipes  209 ,  211 . The valve  201  is then presented to the mounting plate  203  to engage the end portions  255 ,  257  of the inlet connectors  251 ,  253  and axially retain the outer end portions  257  by means of the sleeves  269 ,  271  to secure the mixing valve  201  to the mounting plate  203 . The valve  201  can be removed by a reverse procedure, for example for servicing or access to the filters. 
     Referring now to  FIGS. 16 to 20 , there is shown an alternative method for securing the mixing valve  201  to the mounting plate  203 , in which like reference numerals are used to indicate corresponding parts. 
     As shown, the mounting plate  203  is provided with a pair of clamps  285 ,  287  mounted on the front of the mounting plate  203  adjacent to the marginal edge of the apertures  205 ,  207  for co-operating with the inlet connectors  251 ,  253  of the mixing valve  201 . The clamps and connectors are similar and one clamp and connector will now be described in more detail, it being understood that the description applies to the other clamp and connector. 
     The clamp  285  includes a clip  289  of generally C-shape to extend partly around the aperture  205  and a grub screw  291  for adjusting the position of the clip  289  relative to the aperture  205 . The clip may be made of plastics or other materials such as elastomers or metals. 
     The grub screw  291  is threadably engaged within a housing  293  and has an enlarged head  295  at one end that is located in a channel  297  on the clip  289 . The other end of the grub screw  291  is accessible through the housing to insert a tool (not shown) for rotating the grub screw  291  to adjust the axial position of the grub screw  291  and move the clip  289  in a radial direction relative to the aperture  205 . The clip  289  has an internal side face  299  provided with an angled surface or chamfer  301  on the underside adjacent to the mounting plate  203 . 
     The inlet connector  251  is a unitary component attached at one end to the valve body  239 . The screw threads on the connector  251  and boss  213  described above are omitted and the other end of the connector  251  is a push-fit in the boss  213 . The connector  251  has an annular groove  303  in the outer surface provided on one side with an angled surface or chamfer  305  that matches the chamfer  301  on the clip  289 . 
     In use, the clamp  285  is adjusted by means of the grub screw  291  to withdraw the clip  289  and provide clearance for the connector  251  to be inserted into the boss  213  to compress the sleeve  269  and grip the end of the supply pipe as described previously. The connector  251  can be inserted until the groove  303  is aligned with the clip  289 . The grub screw  289  is then adjusted to advance the clip  289  towards the connector  251  so that the chamfer  301  on the clip  289  engages the chamfer  305  on the connector  251 . The engagement of the chamfers  301 ,  305  pulls the connector  251  down tight on the mounting plate  203  and secures the connector  251  to the mounting plate  203 . The other connector  253  is secured in similar manner. 
     The connectors  251 ,  253  may be permanently attached to the valve body  239  or may be detachable. Where the connectors  251 ,  253  are detachable, the valve body  239  may be attached to the connectors  251 ,  253  before or after the connectors  251 ,  253  are attached to the mounting plate  203 . The valve body can be removed by a reverse procedure. In other respects, the construction and operation of this mixing valve and mounting plate is the same as the embodiment of  FIGS. 10 to 14  and may include any of the modifications thereof. 
     As will be appreciated from the description of the exemplary embodiments, the invention enables a mixing valve to be connected to and disconnected from hot and cold water supply pipes without the use of compression joints employing olives that are fixed to the pipes when the joints are assembled. The inlets of the mixing valve and sleeves co-operate to clamp the pipes in position and the clamping force is released when the valve is detached allowing the sleeves to be slid off of the pipes and the mounting plate to be detached from the wall. 
     While the invention has been described with reference to particular embodiments, it will be understood that the invention is not limited thereto and that the invention has application for installation of other types of mixing valves. Furthermore, the invention may have application to other installations requiring a releasable fluid connection between a supply pipe and a fitting, for example a tap. 
     Moreover, it will be understood that the exemplary embodiments are not limiting on the scope of protection and that the principles and concepts described herein can be provided in different forms with the same or equivalent means for achieving the desired result. All such forms of the invention and means for achieving same are within the scope of the invention. 
     Additionally or alternatively, features and/or modifications of any of the embodiments described herein may be employed separately or in combination with features and/or modifications of any other embodiment.