Patent Publication Number: US-2023139386-A1

Title: Watertightness testing method and assembling device

Description:
TECHNICAL FIELD 
     The present invention relates to a watertightness testing method of a joined section of pipes and to an assembling device used in the watertightness testing method. 
     BACKGROUND ART 
     Conventionally, examples of a watertightness testing method of this type include a method using a watertightness testing device  201  as shown in  FIG.  16   . Specifically, the watertightness testing device  201  includes a testing device body  205  which performs a watertightness test of a joined section  204  of pipes  202  and  203  inside the pipes  202  and  203  and a moving operation rod  206  for moving the testing device body  205  inside the pipes  202  and  203  in a pipe axial direction B. 
     The testing device body  205  includes a cylindrical member  207  and a pair of annular water stop bags  208  which are provided in the cylindrical member  207  and of which a diameter-expanding operation can be performed. An annular sealed space  209  enclosed by both water stop bags  208  of which a diameter-expanding operation has been performed to a water-stopping state, an outer circumferential surface of the cylindrical member  207 , and inner circumferential surfaces of the pipes  202  and  203  is formed in the joined section  204 . 
     The testing device body  205  inspects water leakage from an elastic seal  211  of the joined section  204  by supplying water  210  for a water pressure test to inside of the sealed space  209  and applying water pressure. 
     The moving operation rod  206  is attached to the cylindrical member  207  of the testing device body  205  and extends along the pipe axial direction B. 
     Accordingly, after joining a second pipe  203  to a first pipe  202 , the moving operation rod  206  is operated to move the testing device body  205  to the joined section  204 . Subsequently, diameters of both water stop bags  208  are expanded, the water  210  for a water pressure test is supplied to the inside of the sealed space  209 , and water pressure is applied in order to inspect water leakage from the elastic seal  211  of the joined section  204 . 
     Refer to Japanese Patent Laid-Open No. 2013-40866 for information on the watertightness testing device  201  described above. 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in the conventional form described above, when performing a watertightness test, there is a risk that the second pipe  203  may become pressed in a separating direction H by water pressure acting inside the annular sealed space  209  and that the second pipe  203  may become detached from the first pipe  202 . 
     An object of the present invention is to provide a watertightness testing method and an assembling device capable of preventing a second pipe from becoming detached from a first pipe during a watertightness test. 
     Solution to Problem 
     A watertightness testing method according to the present invention for testing watertightness of a joined section where one end section of a second pipe is joined to a first pipe includes: 
     inserting, into the first pipe, a testing device body of a watertightness testing device for performing a watertightness test inside a pipe; 
     attaching an assembling device to another end section of the second pipe; 
     attaching a pulling device to the assembling device and connecting the pulling device to a strap-shaped member having been wound in advance around an outer circumference of the first pipe; 
     operating the pulling device and pulling the strap-shaped member in a separating direction of the second pipe to have a reaction force generated in the second pipe cause the second pipe to be pulled in a joining direction, the one end section of the second pipe to be inserted into an end section of the first pipe, and the one end section of the second pipe to be joined to the first pipe; and 
     operating a moving operation rod provided in the testing device body from outside of the other end section of the second pipe in a state where the second pipe is being pulled in the joining direction to move the testing device body to the joined section inside the pipe and performing a watertightness test of the joined section. 
     Accordingly, since a watertightness test of a joined section is performed using the testing device body in a state where, after the second pipe is joined to the first pipe, the second pipe is being pulled in a joining direction, the second pipe is restrained by the first pipe via the assembling device, the pulling device, and the strap-shaped member in the pipe axial direction while the watertightness test is in progress. As a result, the second pipe can be prevented from becoming detached from the first pipe. 
     With the watertightness testing method according to the present invention, preferably, when operating the moving operation rod from outside of the other end section of the second pipe to move the testing device body to the joined section inside the pipe, the moving operation rod is passed through a passage space secured in a central part of the other end section of the second pipe and pulled outside from the other end section of the second pipe without interfering with the assembling device. 
     Accordingly, since the moving operation rod does not interfere with the assembling device when the moving operation rod is operated from outside of the other end section of the second pipe, the moving operation rod can be readily pulled outside from the other end section of the second pipe. 
     An assembling device used in the watertightness testing method according to the present invention includes: 
     a frame body attachable to and detachable from the other end section of the second pipe and an attaching section for attaching the pulling device to the frame body, wherein 
     the attaching section is provided on the frame body, and 
     the frame body can be attached to the other end section of the second pipe to be arranged in a periphery of the passage space for pulling out the moving operation rod. 
     Accordingly, the passage space is secured in the other end section of the second pipe in a state where the frame body is attached to the other end section of the second pipe. As a result, the moving operation rod is passed through the passage space and pulled outside from the other end section of the second pipe without interfering with the assembling device. 
     With the assembling device according to the present invention, preferably, the attaching section is provided outside in a pipe diameter direction of the frame body, 
     a fall prevention device for preventing the frame body attached to the other end section of the second pipe from falling outward in the pipe diameter direction is provided on the frame body, and 
     the fall prevention device has a rolling element that can be brought into contact with a wall surface surrounding the pipe. 
     Accordingly, by attaching the frame body of the assembling device to the other end section of the second pipe and attaching the pulling device to the attaching section of the frame body, the pulling device is arranged outside in the pipe diameter direction of the frame body. 
     When the strap-shaped member is pulled in the separating direction of the second pipe by operating the pulling device in this state, an outward external force in the pipe diameter direction acts on the frame body. However, due to the rolling element of the fall prevention device coming into contact with the wall surface against the external force, the frame body is supported on a side of the wall surface by the fall prevention device. Accordingly, the frame body can be prevented from falling outward in the pipe diameter direction. 
     In addition, when joining the second pipe to the first pipe, since the rolling element of the fall prevention device rolls in the joining direction while maintaining contact with the wall surface as the second pipe moves in the joining direction, the assembling device smoothly moves together with the second pipe in the joining direction. 
     With the assembling device according to the present invention, preferably, the fall prevention device has a position adjuster that moves a position of the rolling element in the pipe diameter direction. 
     Accordingly, by moving the position of the rolling element in the pipe diameter direction in accordance with a position of the wall surface, the rolling element can be reliably brought into contact with the wall surface. 
     Advantageous Effects of Invention 
     As described above, according to the present invention, a watertightness test of a joined section is performed using the testing device body in a state where, after joining the second pipe to the first pipe, the second pipe is being pulled in a joining direction. Therefore, while the watertightness test is in progress, the second pipe is restrained by the first pipe via the assembling device, the pulling device, and the strap-shaped member in the pipe axial direction. Accordingly, the second pipe can be prevented from becoming detached from the first pipe. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a sectional view of a testing device body of a watertightness testing device used in a watertightness testing method according to a first embodiment of the present invention showing a state where indentation of first and second sealing members has been released. 
         FIG.  2    is a sectional view of the testing device body of the watertightness testing device according to the first embodiment of the present invention showing a state where the first and second sealing members have been indented. 
         FIG.  3    is an arrow view taken along X-X in  FIG.  1   . 
         FIG.  4    is a side view showing a procedure of the watertightness testing method using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  5    is a side view showing a procedure of the watertightness testing method using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  6    is a side view showing a procedure of the watertightness testing method using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  7    is a side view showing a procedure of the watertightness testing method using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  8    is an arrow view taken along X-X in  FIG.  6   . 
         FIG.  9    is an arrow view taken along X-X in  FIG.  8   . 
         FIG.  10    is an arrow view taken along X-X in  FIG.  9   . 
         FIG.  11    is a front view of one of two frame bodies of an assembling device used in the watertightness testing method according to the first embodiment of the present invention. 
         FIG.  12    is a rear view of one of the frame bodies of the assembling device according to the first embodiment of the present invention. 
         FIG.  13    is a plan view of one of the frame bodies of the assembling device according to the first embodiment of the present invention. 
         FIG.  14    is a side view of one of the frame bodies of the assembling device according to the first embodiment of the present invention. 
         FIG.  15    is a front view of an assembling device according to a second embodiment. 
         FIG.  16    is a sectional view for describing a watertightness testing method using a conventional watertightness testing device. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the drawings. 
     First Embodiment 
     In the first embodiment, as shown in  FIGS.  1  to  3   , reference numeral  1  denotes a watertightness testing device for performing a watertightness test of a joined section  4  between joined pipes  2  and  3 . The pipes  2  and  3  are each a PN type ductile pipe having a spigot  6  at one end section and a socket  7  at another end section. The pipes  2  and  3  are joined and arranged inside a conduit installation tunnel  9  (refer to  FIG.  4   ) formed underground and constitute a conduit  10  (refer to  FIG.  4   ). The pipes  2  and  3  are surrounded by an inner wall surface  9   a  of the conduit installation tunnel  9 . 
     In the joined section  4 , joining is achieved by inserting the spigot  6  of a second pipe  3  into the socket  7  of a first pipe  2 . A locking-ring housing groove  12  and a sealing body mounting depression  13  are formed on an inner circumferential surface of the socket  7 . 
     A locking-ring  15  for preventing separation is housed in the locking-ring housing groove  12 . In addition, an annular sealing body  16  made of an elastic material such as rubber is mounted to the sealing body mounting depression  13 . The sealing body  16  is sandwiched between an outer circumferential surface of the spigot  6  and the inner circumferential surface of the socket  7  and compressed in a pipe diameter direction A. Accordingly, sealing is achieved between the spigot  6  and the socket  7 . 
     As shown in  FIG.  4   , the watertightness testing device  1  includes a testing device body  21  which performs a watertightness test of the joined section  4  inside the pipes  2  and  3  and a moving operation rod  22  for moving the testing device body  21  inside the pipes  2  and  3  in a pipe axial direction B by a remote operation. 
     The testing device body  21  will be described below. 
     As shown in  FIGS.  1  to  3   , the testing device body  21  has a cylindrical core  25 , first and second sealing members  26  and  27 , first and second indenting members  29  and  30 , a moving device  32 , a testing fluid supplying device  33 , and a supporting device  34 . 
     The first sealing member  26  is an annular member made of an elastic material such as rubber and provides a seal between an outer circumferential surface of the core  25  and an inner circumferential surface of the second pipe  3 . In addition, the second sealing member  27  is an annular member made of an elastic material such as rubber and provides a seal between the outer circumferential surface of the core  25  and an inner circumferential surface of the first pipe  2 . 
     An engaging depression  36  is respectively formed around a whole circumference on an outer circumferential surface of a proximal end section of the first and second sealing members  26  and  27 . 
     A first sealing member insertion space  37  is formed around a whole circumference between the outer circumferential surface of the core  25  and the inner circumferential surface of the second pipe  3 . In addition, a second sealing member insertion space  38  is formed around a whole circumference between the outer circumferential surface of the core  25  and the inner circumferential surface of the first pipe  2 . 
     The first indenting member  29  indents and compresses the first sealing member  26  into the first sealing member insertion space  37  and has an engaging protrusion  40  formed around a whole circumference. 
     In addition, the second indenting member  30  indents and compresses the second sealing member  27  into the second sealing member insertion space  38  and has the engaging protrusion  40  in a similar manner to the first indenting member  29 . 
     The engaging protrusion  40  of the first indenting member  29  is fitted into the engaging depression  36  of the first sealing member  26 . Accordingly, the first sealing member  26  and the first indenting member  29  engage each other in the pipe axial direction B. In addition, the engaging protrusion  40  of the second indenting member  30  is fitted into the engaging depression  36  of the second sealing member  27 . Accordingly, the second sealing member  27  and the second indenting member  30  engage each other in the pipe axial direction B. 
     The moving device  32  is a device that moves the first indenting member  29  and the second indenting member  30  in an indenting direction C (refer to  FIG.  2   ) in which both indenting members  29  and  30  approach each other in the pipe axial direction B and an indentation releasing direction D (refer to  FIG.  1   ) in which both indenting members  29  and  30  separate from each other in the pipe axial direction B. 
     Specifically, the moving device  32  has a pipe-like mobile rod  42  which is attached to the second indenting member  30  and which is movable in the pipe axial direction B, a receiving member  43  provided in a tip section of the mobile rod  42 , and a plurality of double-acting jacks  44  that are extensible and retractable in the pipe axial direction B. The double-acting jacks  44  are attached between the first indenting member  29  and the receiving member  43 . As shown in  FIG.  7   , a hydraulic oil pump  59  is connected to the double-acting jacks  44  via hydraulic oil piping  58 . By activating the hydraulic oil pump  59 , a plunger  45  of the double-acting jacks  44  is extended and retracted. 
     As shown in  FIGS.  1  to  3   , the supporting device  34  is a device that supports the core  25 , the first and second indenting members  29  and  30 , and the moving device  32  and has a shaft  46  inserted into the mobile rod  42 , a plurality of leg frames  47  provided in both end sections of the shaft  46 , and a moving wheel  48  rotatably provided in a lower end section of the leg frames  47 . The moving wheels  48  are distributed in a pipe circumferential direction E and are capable of rolling on the inner circumferential surfaces  2   a  and  3   a  of the pipes  2  and  3  in the pipe axial direction B. 
     As shown in  FIG.  2   , when the first and second indenting members  29  and  30  move in the indenting direction C and reach an indenting position P 1 , the first and second sealing members  26  and  27  are indented into the first and second sealing member insertion spaces  37  and  38 . 
     In addition, as shown in  FIG.  1   , when the first and second indenting members  29  and  30  move in the indentation releasing direction D and return to an indentation releasing position P 2 , the indentation of the first and second sealing members  26  and  27  is released. 
     As shown in  FIGS.  1  and  2   , when the testing device body  21  is set to the joined section  4  in the pipes  2  and  3 , a test space  50  is formed around a whole circumference between the outer circumferential surface of the core  25  and the inner circumferential surfaces  2   a  and  3   a  of the pipes  2  and  3  in the pipe diameter direction A and between the first sealing member  26  and the second sealing member  27  in the pipe axial direction B. The test space  50  is communicated with the sealing body mounting depression  13  via a gap  51  between a deep end of the socket  7  and a tip of the spigot  6 . 
     The testing fluid supplying device  33  is a device that supplies the test space  50  with water  53  (an example of a testing fluid) from inside the core  25  and has a water supply hose  54  connected to a lower part of an inner circumference of the core  25  and a hydraulic pump  55  (refer to  FIG.  7   ) provided at a tip of the water supply hose  54 . 
     In addition, an air vent hose  57  for deaerating an inside of the test space  50  is connected to an upper part of the inner circumference of the core  25 . The water supply hose  54  and the air vent hose  57  penetrate the first indenting member  29 . 
     As shown in  FIG.  4   , the moving operation rod  22  has an elongated operation rod main body  60  which is attachably and detachably coupled to a tip section of the shaft  46  of the testing device body  21  and which extends in the pipe axial direction B, first and second main supporting members  61  and  62  which support the operation rod main body  60  on an inner wall surface  9   a  of the conduit installation tunnel  9  outside of the pipes  2  and  3 , and first and second auxiliary supporting members  64  and  65  which support the operation rod main body  60  on the inner circumferential surface  3   a  inside the second pipe  3 . The water supply hose  54 , the air vent hose  57 , and the hydraulic oil piping  58  are arranged along the moving operation rod  22  from the testing device body  21 . 
     Each of the first and second main supporting members  61  and  62  has a leg frame  67  suspended downward from the operation rod main body  60  and a pair of main wheels  68  provided in a lower end section of the leg frame  67 . The pair of main wheels  68  are distributed in the pipe circumferential direction E. 
     In addition, the leg frame  67  can be switched between a supporting posture K (refer to  FIG.  4   ) in which the leg frame  67  extends in the pipe diameter direction A and a folded posture L (refer to  FIG.  5   ) in which the leg frame  67  is folded inside the pipe  3 . The leg frame  67  is urged from the folded posture L to the supporting posture K by a spring cylinder  69 . 
     Each of the first and second auxiliary supporting members  64  and  65  has an attached frame  71  attached to a lower side of the operation rod main body  60  and a pair of auxiliary wheels  72  provided in a lower end section of the attached frame  71 . As shown in  FIG.  8   , the pair of auxiliary wheels  72  are distributed in the pipe circumferential direction E. 
     In addition, when a watertightness test of the joined section  4  of the pipes  2  and  3  is to be performed, an assembling device  80  such as that shown in  FIGS.  8  to  14    is used. 
     As shown in  FIGS.  6  to  10   , the assembling device  80  has a pair of frame bodies  81   a  and  81   b  which are attachable to and detachable from an opening end section (an example of an other end section) of the socket  7  of the second pipe  3  and which are divided left and right and attaching plates  83   a  and  83   b  (an example of an attaching section) for attaching a pair of left and right lever hoists  82   a  and  82   b  (an example of a pulling device) to the frame bodies  81   a  and  81   b.    
     Each of the lever hoists  82   a  and  82   b  has an anchor hook  141  provided on a main body side and a connecting hook  143  provided on a tip of a chain  142 . 
     As shown in  FIGS.  11  and  12   , one frame body  81   a  has a mounting plate  86  which is attachable to and detachable from the opening end surface of the socket  7 , a strut  87  which is provided on a front surface of the mounting plate  86  and which extends in the pipe axial direction B, two sets of clamping mechanisms  88  which sandwich the opening end section of the socket  7  in the pipe diameter direction A, and a fall prevention device  89  for preventing the frame bodies  81  attached to the opening end section of the socket  7  of the second pipe  3  from falling toward outside  90  in the pipe diameter direction A. 
     Each of the two clamping mechanisms  88  has a pair of a fixed plate  91  and a mobile plate  92  which oppose each other in the pipe diameter direction A and a moving member  93  which moves the mobile plate  92  relative to the fixed plate  91  in the pipe diameter direction A. The fixed plate  91  is fixed to a rear surface of the mounting plate  86 . 
     The moving member  93  has a bolt body  94  having a male screw on an outer circumference thereof, an engaging piece  95  provided on a tip of the bolt body  94 , an engaging member  96  provided on the mobile plate  92 , and a supporting plate  97  which supports the bolt body  94 . 
     The supporting plate  97  is provided on the rear surface of the mounting plate  86  and a screw hole  98  having a female screw is formed on the supporting plate  97 . The bolt body  94  is rotatably inserted through the screw hole  98  in a state where the male screw and the female screw are screwed and the bolt body  94  is supported by the supporting plate  97 . A diameter of the engaging piece  95  is larger than that of the bolt body  94  and the engaging piece  95  and the engaging member  96  engage each other in an axial center direction of the bolt body  94 . 
     As shown in  FIG.  13   , one of the attaching plates  83   a  has an attaching hole  100  and is provided on an outside surface of the strut  87  of one of the frame bodies  81   a  in the pipe diameter direction A. 
     As shown in  FIGS.  8  to  10  and  13   , the fall prevention device  89  has a roller  101  (an example of a rolling element) which can come into contact with the inner wall surface  9   a  of the conduit installation tunnel  9  and a position adjuster  102  which moves a position of the roller  101  in the pipe diameter direction A. 
     The position adjuster  102  has a screw shaft  103  which penetrates the strut  87  of the frame bodies  81  in the pipe diameter direction A, a bracket  104  provided on a tip of the screw shaft  103 , and an operating handle  106  for rotationally operating the screw shaft  103 . The roller  101  is rotatably provided on the bracket  104 . 
     In addition, the screw shaft  103  has a male screw on an outer circumference thereof and screws with a female screw of a nut body  105  provided on the strut  87 . The screw shaft  103  and the bracket  104  are relatively rotatably coupled to each other around an axial center of the screw shaft  103 . 
     While the one frame body  81   a  is configured as described above, the other frame body  81   b  is also configured in a same manner as the one frame body  81   a.    
     According to the assembling device  80  described above, as indicated by an imaginary line in  FIG.  12   , the opening end section of the socket  7  is inserted between the fixed plate  91  and the mobile plate  92  of the clamping mechanism  88  of the one frame body  81   a  and the bolt body  94  is rotated in one direction to bring the mobile plate  92  close to the fixed plate  91 . Accordingly, a distance between the fixed plate  91  and the mobile plate  92  in the pipe diameter direction A is reduced, the opening end section of the socket  7  is sandwiched between the fixed plate  91  and the mobile plate  92 , and the one frame body  81   a  is attached to the opening end section of the socket  7  as shown in  FIGS.  8  to  10   . 
     In addition, in a similar manner to attaching the one frame body  81   a , the other frame body  81   b  can be attached to the opening end section of the socket  7 . 
     A watertightness testing method of testing watertightness of the joined section  4  of the pipes  2  and  3  using the watertightness testing device  1  described above will be described below. 
     As shown in  FIG.  4   , the first pipe  2  is a pipe at a tail end of the conduit  10  which has already been joined inside the conduit installation tunnel  9  and is supported by a support table  111  made of crossties or the like. In this state, first, the testing device body  21  of the watertightness testing device  1  is inserted into the first pipe  2 . 
     At this point, the operation rod main body  60  of the moving operation rod  22  protrudes outside of an end section of the first pipe  2  from the socket  7  of the first pipe  2  and is supported on the inner wall surface  9   a  of the conduit installation tunnel  9  by the first and second main supporting members  61  and  62  having been switched to the supporting posture K. 
     The locking-ring  15  has been housed in advance in the locking-ring housing groove  12  and the sealing body  16  has been mounted in advance to the sealing body mounting depression  13  inside the socket  7  of the first pipe  2 . 
     In addition, the plunger  45  of the double-acting jack  44  of the testing device body  21  is shortened and the first and second indenting members  29  and  30  are returned to the indentation releasing position P 2  (refer to  FIG.  1   ). 
     Furthermore, as shown in  FIG.  4   , two sling belts  112   a  and  112   b  (an example of a strap-shaped member) are wound around an outer circumference of the socket  7  of the first pipe  2  in advance in a state of being distributed left and right (refer to  FIG.  9   ). At the same time, a recovery rope  113  for recovering both sling belts  112   a  and  112   b  is connected to each of the sling belts  112   a  and  112   b . Each of the sling belts  112   a  and  112   b  has eye sections  145  and  146  at both ends thereof. 
     Next, as shown in  FIG.  5   , the second pipe  3  is loaded on a transfer carriage  115  and the transfer carriage  115  is caused to travel in a joining direction G to transfer the second pipe  3  up to a front side of the first pipe  2 . 
     In doing so, due to an opening end section of the spigot  6  of the second pipe  3  coming into contact with the first and second main supporting members  61  and  62  of the moving operation rod  22  of the watertightness testing device  1 , the leg frames  67  of the first and second main supporting members  61  and  62  are switched from the supporting posture K to the folded posture L and the moving operation rod  22  is inserted into the second pipe  3 . At this point, the operation rod main body  60  is supported on the inner circumferential surface  3   a  of the second pipe  3  by the first and second auxiliary supporting members  64  and  65 . 
     Subsequently, the assembling device  80  is attached to the opening end section of the socket  7  of the second pipe  3 . Specifically, as indicated by an imaginary line in  FIG.  12   , by inserting the opening end section of the socket  7  of the second pipe  3  between the fixed plate  91  and the mobile plate  92  of the one frame body  81   a  and rotating the bolt body  94  in one direction to bring the mobile plate  92  close to the fixed plate  91 , the opening end section of the socket  7  of the second pipe  3  is sandwiched between the mobile plate  92  and the fixed plate  91  in the pipe diameter direction A. Accordingly, as shown in  FIGS.  6  and  8  to  10   , the one frame body  81   a  is attached to the opening end section of the socket  7  of the second pipe  3 . 
     By attaching the other frame body  81   b  to the opening end section of the socket  7  of the second pipe  3  in a similar manner, the assembling device  80  is attached to the opening end section of the socket  7  of the second pipe  3 . 
     In doing so, as shown in  FIGS.  8  and  9   , a passage space  117  for pulling out the moving operation rod  22  is secured between the one frame body  81   a  and the other frame body  81   b  in a central part of the socket  7  (the other end section) of the second pipe  3  and in the pipe diameter direction A. The one and the other frame bodies  81   a  and  81   b  are arranged around the passage space  117 . 
     In addition, as shown in  FIGS.  9  and  10   , the anchor hook  141  of one lever hoist  82   a  is hooked to the attaching hole  100  of one attaching plate  83   a  and the connecting hook  143  is hooked to the eye section  146  of one sling belt  112   a . Furthermore, the anchor hook  141  of the other lever hoist  82   b  is hooked to the attaching hole  100  of the other attaching plate  83   b  and the connecting hook  143  is hooked to the eye section  146  of the other sling belt  112   b.    
     Accordingly, both left and right lever hoists  82   a  and  82   b  are attached to the assembling device  80  and connected to both left and right sling belts  112   a  and  112   b . In doing so, as shown in  FIG.  9   , the one lever hoist  82   a  is positioned toward outside in the pipe diameter direction A of the one frame body  81   a  and the other lever hoist  82   b  is positioned toward outside in the pipe diameter direction A of the other frame body  81   b.    
     Subsequently, as shown in  FIGS.  6 ,  9 , and  10   , due to a worker  118  operating a lever  144  of both lever hoists  82   a  and  82   b , both sling belts  112   a  and  112   b  are pulled in the separating direction H of the second pipe  3  and a reaction force F is generated in the second pipe  3  in reaction thereto. The second pipe  3  is pulled in the joining direction G by the reaction force F and the spigot  6  (the one end section) of the second pipe  3  is inserted into the socket  7  of the first pipe  2 . Accordingly, the second pipe  3  is joined to the first pipe  2 . 
     In doing so, as shown in  FIGS.  6 ,  8 , and  9   , a tip section of the moving operation rod  22  of the watertightness testing device  1  passes through the passage space  117  and protrudes outside of an end section from the socket  7  of the second pipe  3  without interfering with the assembling device  80 . In addition, the second pipe  3  is supported by the support table  111 . 
     As described above, in a state where the second pipe  3  is being pulled in the joining direction G using the lever hoists  82   a  and  82   b , as shown in  FIG.  7   , the worker  118  operates the tip section of the moving operation rod  22  of the watertightness testing device  1  from outside of an end section of the socket  7  of the second pipe  3  and moves the testing device body  21  to the joined section  4  of the pipes  2  and  3 . 
     In doing so, as shown in  FIGS.  8  and  9   , the moving operation rod  22  passes through the passage space  117  and protrudes outside of the end section from the socket  7  of the second pipe  3  without interfering with the assembling device  80 . Therefore, the moving operation rod  22  can be readily pulled outside from the socket  7  of the second pipe  3 . At this point, as shown in  FIG.  7   , since the first main supporting member  61  is pulled outside of the second pipe  3  and switched from the folded posture L to the supporting posture K, the operation rod main body  60  is supported on the inner wall surface  9   a  of the conduit installation tunnel  9  by the first main supporting member  61 . 
     In addition, as shown in  FIG.  1   , since the first and second indenting members  29  and  30  have been returned to the indentation releasing position P 2 , compression of the first and second sealing members  26  and  27  is released and the testing device body  21  can be readily moved in the pipe axial direction B. 
     Subsequently, a watertightness test of the joined section  4  is performed using the testing device body  21 . In doing so, as shown in  FIG.  2   , by activating the hydraulic oil pump  59  (refer to  FIG.  7   ) and extending the plunger  45  of the double-acting jack  44 , the first indenting member  29  moves in the indenting direction C and reaches the indenting position P 1 . At the same time, the mobile rod  42  of the moving device  32  moves in an opposite direction J to the first indenting member  29  and the second indenting member  30  moves in the indenting direction C and reaches the indenting position P 1 . 
     Accordingly, the first indenting member  29  indents the first sealing member  26  into the first sealing member insertion space  37  and compresses the first sealing member  26  and the second indenting member  30  indents the second sealing member  27  into the second sealing member insertion space  38  and compresses the second sealing member  27 . As a result, a space between the outer circumferential surface of the core  25  and the inner circumferential surface of the second pipe  3  is sufficiently sealed by the compressed first sealing member  26  and a space between the outer circumferential surface of the core  25  and the inner circumferential surface of the first pipe  2  is sufficiently sealed by the compressed second sealing member  27 . 
     Subsequently, the hydraulic pump  55  (refer to  FIG.  7   ) is activated to supply water  53  to the test space  50  from the water supply hose  54 . Accordingly, while air inside the test space  50  and inside the sealing body mounting depression  13  is discharged through the air vent hose  57 , the water  53  supplied to the test space  50  passes through the gap  51  and fills the sealing body mounting depression  13 . In a state where the test space  50  and the sealing body mounting depression  13  are filled with the water  53  with predetermined pressure in this manner, a watertightness test of the joined section  4  of the pipes  2  and  3  is performed by inspecting a presence or absence of leakage or the like of the water  53  from the sealing body  16 . 
     According to the watertightness testing method described above, as shown in  FIG.  7   , since a watertightness test of the joined section  4  of the pipes  2  and  3  is performed using the testing device body  21  in a state where the second pipe  3  is being pulled in the joining direction G after joining the second pipe  3  to the first pipe  2  using the lever hoists  82   a  and  82   b , the second pipe  3  is restrained by the first pipe  2  via the assembling device  80 , the lever hoists  82   a  and  82   b , and the sling belts  112   a  and  112   b  in the pipe axial direction B while the watertightness test is in progress. Accordingly, as shown in  FIG.  2   , the second pipe  3  can be prevented from becoming detached from the first pipe  2  by pressure of the water  53  that fills the test space  50  and the sealing body mounting depression  13  during the watertightness test. 
     In addition, as shown in  FIG.  6   , when the worker  118  operates the lever  144  of the one lever hoist  82   a  and pulls the one sling belt  112   a  in the separating direction H of the second pipe  3 , as shown in  FIG.  9   , an outward external force f in the pipe diameter direction A acts on the one frame body  81   a . As the roller  101  of the fall prevention device  89  comes into contact with the inner wall surface  9   a  of the conduit installation tunnel  9  against the external force f, the one frame body  81   a  is supported on a side of the inner wall surface  9   a  by the fall prevention device  89 . Accordingly, the one frame body  81   a  can be prevented from falling toward outside  90  in the pipe diameter direction A. 
     In a similar manner, since the other frame body  81   b  is also supported on the side of the inner wall surface  9   a  of the conduit installation tunnel  9  by the fall prevention device  89 , the other frame body  81   b  can be prevented from falling toward outside  90  in the pipe diameter direction A. 
     In addition, when joining the second pipe  3  to the first pipe  2 , since the roller  101  of the fall prevention device  89  rolls in the joining direction G while maintaining contact with the inner wall surface  9   a  of the conduit installation tunnel  9  as the second pipe  3  moves in the joining direction G, the assembling device  80  smoothly moves together with the second pipe  3  in the joining direction G. 
     Furthermore, by operating the operating handle  106  of the position adjuster  102  and rotating the screw shaft  103 , the position of the roller  101  moves in the pipe diameter direction A. Accordingly, by moving the position of the roller  101  in the pipe diameter direction A in accordance with a position of the inner wall surface  9   a  of the conduit installation tunnel  9 , the roller  101  can be reliably brought into contact with the inner wall surface  9   a  of the conduit installation tunnel  9 . 
     In addition, after performing a watertightness test of the joined section  4  as described above, by repetitively performing a procedure including temporarily detaching the assembling device  80 , the lever hoists  82   a  and  82   b , and the sling belts  112   a  and  112   b , joining another pipe to the second pipe  3 , and performing a watertightness test of the joined section, a watertightness test of a joined section can be performed while joining pipes to each other. 
     As shown in  FIG.  12   , by rotating the bolt body  94  of the assembling device  80  in the other direction to separate the mobile plate  92  from the fixed plate  91  and detaching both frame bodies  81   a  and  81   b  from the opening end section of the socket  7  of the second pipe  3 , the testing device body  21  can be taken outside from the opening end section of the socket  7  of the second pipe  3 . 
     Furthermore, by operating the recovery rope  113  after detaching the frame bodies  81   a  and  81   b  and the lever hoists  82   a  and  82   b  of the assembling device  80 , the sling belts  112   a  and  112   b  can be separated from the outer circumference of the socket  7  of the first pipe  2  and can be recovered. 
     Second Embodiment 
     While an assembling device  80  has a pair of frame bodies  81   a  and  81   b  having been divided left and right as shown in  FIG.  8    in the first embodiment described above, as a second embodiment, a mounting plate  86  of one frame body  81   a  and a mounting plate  86  of another frame body  81   b  may be coupled to each other by a pair of upper and lower coupling frames  125  and  126 . In this case, a passage space  117  is secured between the left and right backing plates  86  of the frame bodies  81   a  and  81   b  and between the upper and lower coupling frames  125  and  126 . 
     In addition, in the respective embodiments described above, while the two frame bodies  81   a  and  81   b  are attached to the socket  7  of the second pipe  3  by being distributed at angles that differ by 180 degrees as shown in  FIG.  8   , the number of frame bodies is not limited to two. For example, three frame bodies may be attached to the socket  7  of the second pipe  3  by being distributed at angles that differ by 120 degrees. 
     Furthermore, in the respective embodiments described above, while a moving operation rod  22  has an operation rod main body  60 , main supporting members  61  and  62 , and auxiliary supporting members  64  and  65  as shown in  FIG.  4   , the moving operation rod  22  may not include at least one of the main supporting members  61  and  62  and the auxiliary supporting members  64  and  65 . 
     Moreover, while a case where pipes are laid in a conduit installation tunnel  9  that is an existing pipeline, a tunnel, a shield, or the like has been described in the embodiments presented above, the present invention is not limited to cases inside the conduit installation tunnel  9  and can also be applied to a case (an open-cut method) in which pipes are laid inside a groove cut out from ground.