Patent Publication Number: US-2023141092-A1

Title: Watertightness testing device and watertightness testing method

Description:
TECHNICAL FIELD 
     The present invention relates to a watertightness testing device and a watertightness testing method for performing a watertightness test of a joined section of pipes. 
     BACKGROUND ART 
     Conventionally, as a watertightness testing device of this type, as shown in  FIG.  16   , there is a watertightness testing device including a testing device body  124  which performs a watertightness test of a joined section  123  of pipes  121  and  122  inside the pipes  121  and  122  and a moving operation rod  125  for moving the testing device body  124  inside the pipes  121  and  122  in a pipe axial direction B. 
     The testing device body  124  includes a cylindrical member  127  and a pair of annular water stop bags  128  which are provided in the cylindrical member  127  and of which a diameter-expanding operation can be performed. An annular sealed space  129  enclosed by both water stop bags  128  of which a diameter-expanding operation has been performed to a water-stopping state, an outer circumferential surface of the cylindrical member  127 , and inner circumferential surfaces of the pipes  121  and  122  is formed in the joined section  123 . 
     The testing device body  124  inspects water leakage from an elastic seal  131  of the joined section  123  by supplying water  130  for a water pressure test from a water filling pipe  132  to inside of the sealed space  129 , filling the sealed space  129  with the water  130 , and applying water pressure. 
     The moving operation rod  125  is attached to the cylindrical member  127  of the testing device body  124  and extends along the pipe axial direction B. 
     Accordingly, by performing an operation of pushing or pulling the moving operation rod  125  in the pipe axial direction B, a worker can move the testing device body  124  in the pipes  121  and  122  in the pipe axial direction B and position the testing device body  124  at the joined section  123 . In addition, after performing a watertightness test with respect to the joined section  123  of the pipes  121  and  122 , the worker can move the moving operation rod  125  in the pipe axial direction B and take the testing device body  124  outside from an opening end section of the pipe  122 . 
     Refer to Japanese Patent Laid-Open No. 2013-40866 for information on the watertightness testing device described above. 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in the watertightness testing device described in Japanese Patent Laid-Open No. 2013-40866, since the moving operation rod  125  is an elongated member, the moving operation rod  125  is disadvantageously susceptible to downward deflection due to its own weight. In addition, due to stress acting on an attaching portion between the moving operation rod  125  and the cylindrical member  127 , a base of the moving operation rod  125  is disadvantageously susceptible to damage. 
     Therefore, the moving operation rod  125  must be supported by a support table or the like before joining the pipe  122  to the pipe  121 , and there is a risk that the support table may become a hindrance to pipe-joining work when joining the pipe  122  to the pipe  121 . 
     An object of the present invention is to provide a watertightness testing device and a watertightness testing method capable of preventing a moving operation rod from becoming deflected or damaged. 
     Solution to Problem 
     A watertightness testing device for performing a watertightness test of a joined section between joined pipes according to the present invention includes: 
     a testing device body which performs a watertightness test of the joined section of the pipes in the pipes and a moving operation rod for moving the testing device body in the pipes in a pipe axial direction from outside an end section of the joined pipes, wherein the moving operation rod is provided in the testing device body and extends along the pipe axial direction, 
     a main supporting member for supporting the moving operation rod is provided on the moving operation rod outside of the pipes, and 
     the main supporting member has a rotatable main rolling member in a lower end section, the main supporting member is switchable between a supporting posture in which the main supporting member supports the moving operation rod outside of the pipes and a folded posture in which the main supporting member is folded inside the pipes, and the main supporting member is urged from the folded posture toward the supporting posture. 
     Accordingly, when joining the pipes to each other, the main supporting member is switched to the supporting posture in a state where the testing device body is inserted into the pipes and the main supporting member supports the moving operation rod protruding outside from an end section of the pipes. As result, the moving operation rod can be prevented from becoming deflected or damaged. 
     In addition, by operating the moving operation rod in the pipe axial direction in a state where the main supporting member is switched to the supporting posture and supports the moving operation rod protruding outside from an end section of the pipes, the testing device body inside the pipes can be moved in the pipe axial direction. In doing so, since the main rolling member of the main supporting member rotates along the pipe axial direction on a pipe installation surface outside of an end section of the pipes, the moving operation rod can be readily operated in the pipe axial direction. 
     Furthermore, when inserting the moving operation rod into the pipes, the main supporting member retreats into the pipes by being switched to the folded posture. Therefore, the moving operation rod can be readily inserted into the pipes to join the pipes to each other. Accordingly, when joining the pipes to each other, the main supporting member does not become a hindrance to joining the pipes. 
     With the watertightness testing device according to the present invention, preferably, an auxiliary supporting member which supports the moving operation rod inside the pipes is provided on the moving operation rod, and 
     the auxiliary supporting member has a rotatable auxiliary rolling member in a lower end section. 
     Accordingly, when the moving operation rod is being inserted into the pipes, the auxiliary supporting member supports the moving operation rod inside the pipes. As result, the moving operation rod can be prevented from becoming deflected or damaged. 
     In addition, when operating the moving operation rod in the pipe axial direction, since the auxiliary rolling member rotates along the pipe axial direction on a pipe inner surface, the moving operation rod can be readily operated in the pipe axial direction. 
     With the watertightness testing device according to the present invention, preferably, a tip section of the moving operation rod protrudes outside from an end section of the joined pipes in a state where the testing device body is positioned in the joined section of the pipes. 
     Accordingly, after positioning the testing device body at the joined section of the pipes and performing a watertightness test of the joined section, the tip section of the moving operation rod can be readily operated from outside an end section of the pipes. 
     With the watertightness testing device according to the present invention, preferably, the testing device body has a rotatable moving rolling member for moving inside the pipes in the pipe axial direction. 
     Accordingly, by operating the moving operation rod in the pipe axial direction, the testing device body readily and smoothly moves inside the pipes in the pipe axial direction in conjunction with the moving operation rod. 
     A watertightness testing method using the watertightness testing device according to the present invention includes: 
     supporting a moving operation rod protruding outside from an end section of a first pipe with a main supporting member in a supporting posture in a state where a testing device body is being inserted into the first pipe; 
     moving a second pipe in a joining direction toward the end section of the first pipe; 
     causing the main supporting member to be switched from the supporting posture to a folded posture and to retreat into the second pipe by having one end section of the second pipe come into contact with the main supporting member and push the main supporting member in the joining direction; 
     joining the one end section of the second pipe to the end section of the first pipe in a state where the moving operation rod is inserted into the second pipe; operating the moving operation rod from outside of another end section of the second pipe to move the testing device body to a joined section between the first pipe and the second pipe; and 
     after performing a watertightness test of the joined section with the testing device body, by operating the moving operation rod from outside of the other end section of the second pipe to move the testing device body from the joined section toward the other end section of the second pipe, causing the main supporting member to protrude outside from the other end section of the second pipe, to be switched from the folded posture toward the supporting posture, and to support the moving operation rod protruding outside from the other end section of the second pipe. 
     Accordingly, since the moving operation rod protruding outside from the end section of the first pipe is supported by the main supporting member in the supporting posture in a state where the testing device body is being inserted into the first pipe, the moving operation rod can be prevented from becoming deflected or damaged. 
     In addition, since the main supporting member is switched to the folded posture and retreats into the second pipe when joining the one end section of the second pipe to the end section of the first pipe, the main supporting member does not become a hindrance to joining the pipes. 
     In addition, after joining the pipes to each other and performing a watertightness test, by operating the moving operation rod in the pipe axial direction from outside of the other end section of the second pipe to move the testing device body from the joined section toward the other end section of the second pipe, the main supporting member is switched to the supporting posture and supports the moving operation rod protruding outside from the other end section of the second pipe. In doing so, since the main rolling member of the main supporting member rotates along the pipe axial direction on a pipe installation surface outside of the other end section of the second pipe, the moving operation rod can be readily operated in the pipe axial direction. 
     With the watertightness testing method according to the present invention, preferably, the auxiliary supporting member provided on the moving operation rod supports the moving operation rod in the second pipe in a state where the moving operation rod is being inserted into the second pipe. 
     Accordingly, when the moving operation rod is being inserted into the second pipe, the auxiliary supporting member supports the moving operation rod inside the second pipe. As result, the moving operation rod can be prevented from becoming deflected or damaged. 
     Advantageous Effects of Invention 
     As described above, according to the present invention, when joining the pipes to each other, the main supporting member is switched to the supporting posture in a state where the testing device body is inserted into the pipes and the main supporting member supports the moving operation rod protruding outside from an end section of the pipes. As result, the moving operation rod can be prevented from becoming deflected or damaged. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a sectional view of a watertightness testing device 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 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 diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  5    is an enlarged side view of a first main supporting member and a first auxiliary supporting member of the watertightness testing device according to the first embodiment of the present invention showing a state where the first main supporting member has been switched to a supporting posture. 
         FIG.  6    is an arrow view taken along X-X in  FIG.  5   . 
         FIG.  7    is an enlarged side view of the first main supporting member and the first auxiliary supporting member of the watertightness testing device according to the first embodiment of the present invention showing a state where the first main supporting member has been switched to a folded posture. 
         FIG.  8    is an arrow view taken along X-X in  FIG.  7   . 
         FIG.  9    is a diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  10    is a diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  11    is a diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  12    is a diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  13    is a diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  14    is a diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  15    is a diagram showing a procedure when performing a watertightness test using the watertightness testing device according to the first embodiment of the present invention. 
         FIG.  16    is a sectional view of 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  4   , 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 pipe made of ductile cast iron (an example of a ductile cast-iron 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  formed underground and constitute a conduit  10  (refer to  FIG.  12   ). 
     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 . 
     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. 
     The testing device body  21  will be described below. 
     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 formed around a whole circumference on each 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 . 
     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 an example of a moving rolling member for moving the testing device body  21  in the pipe axial direction B and are capable of rolling on pipe inner 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 sealing member  26  is indented into the first sealing member insertion space  37  and the second sealing member  27  is indented into the second sealing member insertion space  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 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 (not illustrated) 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 . 
     The moving operation rod  22  is attachably and detachably coupled to a tip section of the shaft  46  of the testing device body  21  and extends along the pipe axial direction B. The water supply hose  54  and the air vent hose  57  are arranged along the moving operation rod  22  from the testing device body  21 . 
     As shown in  FIG.  4   , the moving operation rod  22  is provided with first and second main supporting members  61  and  62  which support the moving operation rod  22  on an inner wall surface  9   a  (an example of a pipe installation surface) 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 moving operation rod  22  on the pipe inner surface  3   a  inside the second pipe  3 . 
     As shown in  FIGS.  5  to  7   , the first main supporting member  61  is provided in a tip section of the moving operation rod  22  and has a leg frame  67  suspended downward from the moving operation rod  22 , a pair of main wheel devices  68  provided in a lower end section of the leg frame  67 , and a spring cylinder  69  (an example of an urging device) provided on the moving operation rod  22 . The leg frame  67  has an upper frame  70  attached to the moving operation rod  22 , a lower frame  72  pivotably coupled to a lower end section of the upper frame  70  via a coupling shaft  71 , and an attached frame  73  provided in a lower end section of the lower frame  72 . 
     In addition, the pair of main wheel devices  68  are distributed in a pipe circumferential direction E and has a bracket  74  attached to the attached frame  73  and a main wheel  75  (an example of a main rolling member) rotatably provided on the bracket  74 . 
     The spring cylinder  69  has an extensible and retractable piston rod  77  and a tip of the piston rod  77  is coupled to the lower frame  72 . The piston rod  77  is urged in an extending direction J by a spring built into the spring cylinder  69 . 
     The first main supporting member  61  can be switched between a supporting posture K (refer to  FIGS.  4  to  6  and  15   ) in which the first main supporting member  61  protrudes outside the socket  7  (an example of an end section of a pipe) of the pipes  2  and  3  and supports the moving operation rod  22  and a folded posture L (refer to  FIGS.  7  and  12   ) in which the first main supporting member  61  is folded inside the pipe  3 , and the first main supporting member  61  is urged toward the supporting posture K from the folded posture L by the spring cylinder  69 . Due to the lower frame  72  pivoting around the coupling shaft  71 , the lower frame  72  faces directly downward in the supporting posture K as shown in  FIG.  5    but the lower frame  72  faces obliquely downward in the folded posture L as shown in  FIG.  7   . 
     The upper frame  70  of the leg frame  67  is provided with a regulating plate  78  which regulates pivoting of the lower frame  72  in the supporting posture K. When the lower frame  72  pivots in one direction from the folded posture L to be switched to the supporting posture K, the lower frame  72  is prevented from further pivoting in the one direction by coming into contact with the regulating plate  78 . 
     As shown in  FIG.  4   , the second main supporting member  62  is positioned between the first main supporting member  61  and the testing device body  21  and has a similar configuration to the first main supporting member  61 . 
     As shown in  FIGS.  4 ,  5 ,  7 , and  8   , the first auxiliary supporting member  64  is provided between the tip of the moving operation rod  22  and the first main supporting member  61  and has an attached frame  81  attached to a lower side of the moving operation rod  22  and a pair of auxiliary wheel devices  82  provided in a lower end section of the attached frame  81 . 
     The pair of auxiliary wheel devices  82  are distributed in the pipe circumferential direction E and have a bracket  84  attached to the attached frame  81  and an auxiliary wheel  85  (an example of an auxiliary rolling member) rotatably provided on the bracket  84 . 
     As shown in  FIG.  4   , the second auxiliary supporting member  65  is positioned between the first main supporting member  61  and the second main supporting member  62  and has a similar configuration to the first auxiliary supporting member  64 . 
     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. 
     First, as shown in  FIG.  1   , 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 . In addition, as shown in  FIG.  4   , in a state where the testing device body  21  is inserted into the first pipe  2 , the moving operation rod  22  protruding outside from the socket  7  of the first pipe  2  is supported by the first and second main supporting members  61  and  62  in the supporting posture K. 
     In doing so, as shown in  FIGS.  5  and  6   , since the moving operation rod  22  is supported by the first and second main supporting members  61  and  62  as the main wheel  75  of the first and second main supporting members  61  and  62  comes into contact with the inner wall surface  9   a  of the conduit installation tunnel  9 , the moving operation rod  22  can be prevented from becoming deflected or damaged. 
     While the main wheel  75  appears as though being levitated from the inner wall surface  9   a  of the conduit installation tunnel  9  in  FIG.  5   , this is because the position of the main wheel  75  is displaced in the pipe circumferential direction E with respect to a cross section of the conduit installation tunnel  9  shown in  FIG.  5    (refer to  FIG.  6   ). 
     In addition, the locking-ring  15  is housed in advance in the locking-ring housing groove  12  and the sealing body  16  is mounted in advance to the sealing body mounting depression  13  inside the socket  7  of the first pipe  2 . 
     Next, as shown in  FIG.  9   , the second pipe  3  loaded on a transfer carriage (not illustrated) or the like is moved in a joining direction M toward the socket  7  of the first pipe  2 . 
     Furthermore, as shown in  FIGS.  10  and  11   , due to the spigot  6  (the one end section) of the second pipe  3  coming into contact with the main wheel device  68  of the first main supporting member  61  and pushing the first main supporting member  61  in the joining direction M, as shown in  FIG.  7   , the first main supporting member  61  is switched from the supporting posture K to the folded posture L against an urging force of the spring cylinder  69  and retreats into the second pipe  3 . Subsequently, as the spigot  6  of the second pipe  3  comes into contact with the main wheel device  68  of the second main supporting member  62  and pushes the second main supporting member  62  in the joining direction M, as shown in  FIG.  12   , the second main supporting member  62  is switched from the supporting posture K to the folded posture L against an urging force of the spring cylinder  69  and retreats into the second pipe  3 . 
     In a state where the moving operation rod  22  is inserted into the second pipe  3 , the spigot  6  of the second pipe  3  is inserted into the socket  7  (the end section) of the first pipe  2  to join the second pipe  3  to the first pipe  2 . As shown in  FIGS.  8  and  12   , in a state where the moving operation rod  22  is inserted into the second pipe  3 , the auxiliary wheel  85  of the first and second auxiliary supporting members  64  and  65  comes into contact with the pipe inner surface  3   a  of the second pipe  3  and the first and second auxiliary supporting members  64  and  65  support the moving operation rod  22  inside the second pipe  3 . Accordingly, the moving operation rod  22  can be prevented from becoming deflected or damaged. 
     While the auxiliary wheel  85  appears as though being levitated from the pipe inner surface  3   a  of the second pipe  3  in  FIGS.  7  and  12   , this is because the position of the auxiliary wheel  85  is displaced in the pipe circumferential direction E with respect to a cross section of the second pipe  3  shown in  FIGS.  7  and  12    (refer to  FIG.  8   ). 
     In addition, since the first and second main supporting members  61  and  62  are switched to the folded posture L and retreat into the second pipe  3  when joining the second pipe  3  to the first pipe  2 , the first and second main supporting members  61  and  62  do not become a hindrance to joining the pipes  2  and  3 . 
     After the second pipe  3  is joined to the first pipe  2  as described above, as shown in  FIG.  13   , the worker pulls the moving operation rod  22  from outside of the socket  7  (the other end section) of the second pipe  3  and moves the testing device body  21  to the joined section  4  between the first pipe  2  and the second pipe  3 . 
     In doing so, 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. 
     In addition, when the worker pulls the moving operation rod  22  in the pipe axial direction B from outside of the socket  7  of the second pipe  3  as described above, as shown in  FIGS.  7 ,  8 , and  13   , since the auxiliary wheel  85  of the first and second auxiliary supporting members  64  and  65  rotates on the pipe inner surface  3   a  of the second pipe  3  along the pipe axial direction B, the moving operation rod  22  can be readily operated in the pipe axial direction B. 
     As shown in  FIG.  13   , in a state where the testing device body  21  is positioned in the joined section  4 , the tip section of the moving operation rod  22  protrudes outside from the socket  7  of the second pipe  3  (an end section of the joined pipes). 
     In addition, a watertightness test of the joined section  4  of the pipes  2  and  3  is performed using the testing device body  21 . In doing so, as shown in  FIG.  2   , by 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 G 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 is activated to supply water  53  to the test space  50  from the water suction 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 . 
     After performing the watertightness test of the joined section  4  as described above, by shortening the plunger  45  of the double-acting jack  44  as shown in  FIG.  1   , the first and second indenting members  29  and  30  are each returned to the indentation releasing position P 2  and compression of the first and second sealing members  26  and  27  is released. Accordingly, a switch is made to a state where the testing device body  21  is readily movable in the pipe axial direction B. 
     In addition, as shown in  FIG.  14   , the worker pulls the moving operation rod  22  from outside of the socket  7  of the second pipe  3  and moves the testing device body  21  from the joined section  4  toward the socket  7  of the second pipe  3 . 
     Accordingly, first, the first main supporting member  61  protrudes outside from the socket  7  of the second pipe  3 , the first main supporting member  61  is switched from the folded posture L to the supporting posture K by an urging force of the spring cylinder  69  and, as shown in  FIGS.  5  and  6   , the main wheel  75  of the first main supporting member  61  comes into contact with the inner wall surface  9   a  of the conduit installation tunnel  9 . Subsequently, as shown in  FIG.  15   , furthermore, the second main supporting member  62  protrudes outside from the socket  7  of the second pipe  3 , the second main supporting member  62  is switched from the folded posture L to the supporting posture K by an urging force of the spring cylinder  69 , and the main wheel  75  of the second main supporting member  62  comes into contact with the inner wall surface  9   a  of the conduit installation tunnel  9 . Accordingly, the moving operation rod  22  protruding outside from the socket  7  of the second pipe  3  is supported by the first and second main supporting members  61  and  62  and the moving operation rod  22  can be prevented from becoming deflected or damaged. 
     In addition, after a watertightness test as described above, when the worker pulls the moving operation rod  22  in the pipe axial direction B from outside of the socket  7  of the second pipe  3  as shown in  FIG.  15   , since the main wheel  75  of the first and second main supporting members  61  and  62  rotates in the pipe axial direction B on the inner wall surface  9   a  of the conduit installation tunnel  9  outside of the socket  7  of the second pipe  3 , the moving operation rod  22  can be readily operated in the pipe axial direction B. 
     In addition, according to the watertightness testing method described above, as shown in  FIG.  13   , since the tip section of the moving operation rod  22  protrudes outside from the socket  7  of the second pipe  3  in a state where the testing device body  21  is positioned in the joined section  4  of the pipes  2  and  3 , the worker can readily operate the tip section of the moving operation rod  22  from outside of the socket  7  of the second pipe  3  after performing a watertightness test of the joined section  4 . 
     In addition, due to the moving wheel  48  of the testing device body  21  rotating on the pipe inner surfaces  2   a  and  3   a  of the pipes  2  and  3  when operating the moving operation rod  22  in the pipe axial direction B, the testing device body  21  readily and smoothly moves inside the pipes  2  and  3  in the pipe axial direction B in conjunction with the moving operation rod  22 . 
     While the moving operation rod  22  is provided with the first and second main supporting members  61  and  62  and the first and second auxiliary supporting members  64  and  65  in the embodiment described above as shown in  FIG.  4   , the number of main supporting members  61  and  62  may be singular (one) or plural (three or more). In a similar manner, the number of the first and second auxiliary supporting members  64  and  65  may be singular (one) or plural (three or more). 
     While the two main wheels  75  are provided distributedly in the pipe circumferential direction E in the embodiment described above as shown in  FIG.  6   , one main wheel  75  may be provided directly underneath the moving operation rod  22  without being distributed. 
     While the two auxiliary wheels  85  are provided distributedly in the pipe circumferential direction E in the embodiment described above as shown in  FIG.  8   , one auxiliary wheel  85  may be provided directly underneath the moving operation rod  22  without being distributed. 
     Moreover, while a case where pipes are laid in the 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.