Abstract:
A pressure flow stop which can be used for temporarily blocking flow of water from a main water supply line to a residence or business in order to facilitate replacement of a damaged, defective or deteriorated water shutoff valve, or “curbstop”, at the residence or business. The pressure flow stop may include an elongated shaft housing which is removably attached to the damaged, defective or deteriorated water shutoff valve after the water shutoff valve is closed and the water meter is removed from the water shutoff valve, respectively. An elongated inflation shaft, terminated by an inflatable balloon, is slidably disposed in the shaft housing, and the water shutoff valve is opened to facilitate extension of the balloon end of the inflation shaft from the shaft housing, through the water shutoff valve and into the water source pipe leading from the main water line. The balloon is inflated to obstruct the water source pipe and block further flow of water from the pipe into the water shutoff valve as the water shutoff valve is detached from the pipe and removed from over the inflation shaft and as a replacement water shutoff valve is slipped over the inflation shaft and replaced on the pipe. Finally, the balloon is deflated and removed from the pipe and replacement water shutoff valve, the replacement water shutoff valve is closed, the water meter is threaded on the replacement water shutoff valve and the replacement water shutoff valve is opened, respectively, to resume flow of water from the main water line to the residence or business.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation-in-part of my U.S. patent application Ser. No. 09/576,283, filed May 23, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
       Field of the Invention  
         [0002]    This invention relates to a water shutoff valve or “curbstop” changing apparatus and more particularly, to an apparatus which is suitably adapted to temporarily block flow of water through a water shutoff valve of a residence or business in order to facilitate replacing the damaged, deteriorated or defective water shutoff valve, without requiring termination of water flow through the main water line. Accordingly, water service interruption is limited to the residence or business having the damaged, deteriorated or defective water shutoff valve, while water service to the remaining residences or businesses served by the main water line continues during replacement of the valve. The pressure flow stop of this invention may include an elongated shaft housing and an elongated inflation shaft slidably disposed in the shaft housing, which inflation shaft is removably and pneumatically coupled to a balloon stem terminated by an inflatable balloon. In typical application of the pressure flow stop, the water shutoff valve to be replaced is closed, the water meter is unthreaded from the water shutoff valve and the shaft housing is threaded on the water shutoff valve in place of the water meter. The water shutoff valve is opened to facilitate extension of the balloon and inflation shaft from the housing through the water shutoff valve and into the water source pipe leading from the main water line. The balloon is inflated to obstruct the water source pipe and block further flow of water from the pipe into the water shutoff valve. While the water source pipe remains obstructed, the shaft housing is unthreaded from the water shutoff valve, the inflation shaft is uncoupled from the balloon stem, the water shutoff valve is unthreaded from the pipe and slipped over the inflation shaft, a replacement water shutoff valve is slipped over the inflation shaft and threaded on the pipe, the shaft housing is threaded on the replacement water shutoff valve and the inflation shaft is again coupled to the balloon stem After the balloon is deflated, the balloon and inflation shaft are removed from the replacement water shutoff valve, the replacement water shutoff valve is closed and the shaft housing is unthreaded from the replacement water shutoff valve. Finally, the water meter is threaded on the replacement water shutoff valve and the replacement water shutoff valve is opened to resume flow of water from the main water line to the residence or business.  
           [0003]    Modern conventional water systems typically interconnect the water piping systems of multiple residences or businesses. In order to replace a damaged, deteriorated or defective water shutoff valve, commonly known as a “curbstop”, of one of the residences or businesses, the main water line which serves all of the residences or businesses in the system must typically be crimped, frozen or shut off during the replacement operation. However, these conventional techniques may damage the water line, require expensive machinery and refrigerants and shut off the water supply to all of the residences or businesses served by the main water line.  
           [0004]    Accordingly, an object of this invention is to provide a pressure flow stop which is suitably adapted for temporarily blocking flow of water through the water shutoff valve of a residence or business, in order to facilitate replacement of the valve.  
           [0005]    Another object of this invention is to provide an apparatus which is adapted to temporarily terminate flow of water through a water shutoff valve of a residence or business in a water distribution system in order to facilitate replacing the damaged, deteriorated or defective water shutoff valve without requiring termination of waterflow through the main water line and interruption of water supply to other residences or businesses served by the water distribution system.  
           [0006]    Still another object of this invention is to provide a pressure flow stop for temporarily blocking flow of water through a water shutoff valve of a residence or business in order to facilitate replacing the valve, which pressure flow stop is characterized by an elongated housing which is removably attached to the water shutoff valve after the water meter is removed from the valve; and an elongated inflation shaft terminated by an inflatable balloon which is slidably disposed in the housing, wherein the balloon and inflation shaft are extended from the housing and through the open water shutoff valve and positioned in a water source line to which the water shutoff valve is attached, and the balloon is inflated on the shaft to obstruct the water source line or pipe and substantially block flow of water from the water source line to the water shutoff valve to facilitate replacement of the valve.  
           [0007]    Yet another object of this invention is to provide a pressure flow stop for temporarily blocking flow of water from a main water supply line to a residence or business in order to facilitate replacement of a damaged, defective or deteriorated water shutoff valve of the residence or business, which pressure flow stop may include an elongated shaft housing which is initially removably threaded on the damaged, defective or deteriorated water shutoff valve after the water shutoff valve is closed and the water meter is unthreaded from the water shutoff valve; and an elongated inflation shaft which is terminated by an inflatable balloon and is sidably disposed in the shaft housing. The shutoff valve is opened to facilitate extension of the inflation shaft and balloon from the attached shaft housing, through the open water shutoff valve and into the water source line which extends from the main water line. The balloon is then selectively inflated to obstruct the interior of the water source line and block further flow of water from the main water line into the water shutoff valve. The water shutoff valve is detached from the balloon-obstructed water source line and slipped over the inflation shaft, and a replacement water shutoff valve is slipped over the inflation shaft and replaced on the water source line. The shaft housing is threaded on the replacement water shutoff valve as the inflated balloon continues to obstruct the water source line, and the balloon is deflated and the inflation shaft and deflated balloon are removed from the water source line and replacement water shutoff valve. After the replacement water shutoff valve is closed and the shaft housing is unthreaded from the replacement water shutoff valve, the water meter is threaded on the replacement water shutoff valve and the water shutoff valve is opened, respectively, to resume flow of water from the water source line to the residence or business.  
           [0008]    A still further object of this invention is to provide a method of replacing a damaged, deteriorated or defective water shutoff valve or “curbstop” of a residence or business without requiring termination of water service to the other residences or businesses with which the water shutoff valve is connected.  
         SUMMARY OF THE INVENTION  
         [0009]    These and other objects of the invention are provided in a pressure flow stop which can be used to temporarily block flow of water through a damaged, deteriorated or defective water shutoff valve of a residence or business, in order to facilitate replacing the water shutoff valve without requiring termination of water flow in the main water line and interrupting water distribution to other residences or businesses served by the main water line. The pressure flow stop of this invention may include an elongated shaft housing and an elongated inflation shaft slidably disposed in the shaft housing and pneumatically coupled to a balloon stem that is terminated by an inflatable balloon. In typical application of the pressure flow stop, the water shutoff valve to be replaced is closed, the water meter is unthreaded from the water shutoff valve and the shaft housing is threaded on the water shutoff valve in place of the water meter. The water shutoff valve is opened to facilitate extension of the balloon and inflation shaft from the shaft housing, through the water shutoff valve and into the water source pipe leading from the main water line. The balloon is inflated to obstruct the water source pipe and block further flow of water from the pipe into the water shutoff valve. While the water source pipe remains obstructed by the balloon, the shaft housing is unthreaded from the water shutoff valve, the inflation shaft is uncoupled from the balloon stem, the water shutoff valve is unthreaded from the pipe and slipped over the balloon stem, a replacement water shutoff valve is slipped over the balloon stem and threaded on the pipe, the shaft housing is threaded on the replacement water shutoff valve and the inflation shaft is again coupled to the balloon stem. The balloon is deflated in the water source pipe, the inflation shaft, balloon stem and balloon are removed from the water source pipe and replacement water shutoff valve, and the replacement water shutoff valve is closed. Finally, the shaft housing is replaced by the water meter on the replacement water shutoff valve and the replacement water shutoff valve is opened to resume flow of water from the main water line to the residence or business. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The invention will be better understood by reference to the accompanying drawings, wherein:  
         [0011]    [0011]FIG. 1 is a perspective view of an illustrative embodiment of the pressure flow stop of this invention, removably attached to a water shutoff valve connected to a horizontal water source pipe, both illustrated in phantom, in typical application of the pressure flow stop;  
         [0012]    [0012]FIG. 2 is a perspective view of the pressure flow stop illustrated in FIG. 1, removed from the water shutoff valve (not illustrated);  
         [0013]    [0013]FIG. 3 is a perspective view of the inflation shaft component of the pressure flow stop, removed from the shaft housing;  
         [0014]    [0014]FIG. 4 is a perspective view of the balloon stem and balloon components of the pressure flow stop, with the the balloon stem uncoupled from the inflation shaft illustrated in FIG. 3;  
         [0015]    [0015]FIG. 5 is a longitudinal sectional view of the shaft housing component of the pressure flow stop, shown removably threaded on a damaged, deteriorated or defective water shutoff valve, illustrated in phantom, and the deflated balloon of the pressure flow stop extending from the shaft housing, prior to advancing the balloon through the water shutoff valve and into a horizontal water source pipe (in phantom), connected to the water shutoff valve, in typical application of the pressure flow stop;  
         [0016]    [0016]FIG. 6 is a longitudinal sectional view of the shaft housing component of the pressure flow stop illustrated in FIG. 5, with the balloon stem component of the pressure flow stop extending through the water shutoff valve (in phantom) and the balloon component of the pressure flow stop shown inflated and obstructing the horizontal water source pipe (in phantom), connected to the water shutoff valve;  
         [0017]    [0017]FIG. 7 is a longitudinal sectional view of the water shutoff valve and water source pipe (in phantom) illustrated in FIGS. 5 and 6, with the inflation shaft component of the pressure flow stop uncoupled from the balloon stem component of the pressure flow stop, and the balloon stem extending through the damaged, defective or deteriorated water shutoff valve and the inflated balloon of the pressure flow stop, attached to the balloon stem, obstructing the horizontal water source pipe prior to removing the water shutoff valve from the water source pipe;  
         [0018]    [0018]FIG. 8 is a longitudinal sectional view of the water source pipe illustrated in FIG. 7, illustrated in phantom, with the damaged, defective or deteriorated water shutoff valve (not illustrated) removed from the water source pipe and the inflated balloon of the pressure flow stop remaining in obstructing configuration in the water source pipe, after removal of the water shutoff valve from the water source pipe and prior to mounting a replacement water shutoff valve on the water source pipe;  
         [0019]    [0019]FIG. 9 is a longitudinal sectional view of the shaft housing component of the pressure flow stop, connected to an L-shaped damaged, defective or deteriorated water shutoff valve, illustrated in phantom, with the inflation shaft of the pressure flow stop extending through the shaft housing and water shutoff valve and the inflated balloon of the pressure flow stop obstructing a vertical water source pipe (illustrated in phantom), connected to the water shutoff valve;  
         [0020]    [0020]FIG. 10 is a longitudinal sectional view of the water shutoff valve and water source pipe illustrated in FIG. 9, with the balloon stem component of the pressure flow stop extending through the water shutoff valve and the inflated balloon of the pressure flow stop remaining in obstructing configuration in the water source pipe, after removal of the shaft housing from the water shutoff valve and uncoupling of the inflation shaft from the balloon stem prior to removing the water shutoff valve from the water source pipe;  
         [0021]    [0021]FIG. 11 is a longitudinal sectional view of the vertical water source pipe illustrated in FIGS. 9 and 10, illustrated in phantom, with the inflated balloon of the pressure flow stop remaining in obstructing configuration in the water source pipe prior to mounting a replacement water shutoff valve on the water source pipe;  
         [0022]    [0022]FIG. 12 is an exploded, perspective view of the inflation shaft component, partially in section, of the pressure flow stop, with a gland nut provided on the inflation shaft and illustrating seating of a pair of O-rings in respective O-ring grooves provided in the gland nut and;  
         [0023]    [0023]FIG. 13 is a side view, partially in section, of the inflation stem and gland nut illustrated in FIG. 12. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    Referring initially to FIGS. 1 and 9 of the drawings, a conventional water shutoff valve  23  (illustrated in phantom in FIGS. 1 and 9), commonly known as a “curbstop”, typically includes a straight valve housing  27 , as illustrated in FIG. 1, or a generally L-shaped valve housing  27 , as illustrated in FIG. 9. The valve housing  27  is fitted with a valve  28 . A water meter (not illustrated) is typically threadibly attached to a water meter coupling  24  of the valve housing  27 , and a water line coupling  25  of the valve housing  27  is threaded in fluid communication with a water source pipe  30  (illustrated in phantom in FIGS. 1 and 9), connected to a main water line (not illustrated). A constant supply of water is normally distributed from the main water line to each of multiple residences or businesses, through the water source line  30 , valve housing  27 , open valve  28  of the water shutoff valve  23 , and connected water meter, and into a water service pipe (not illustrated) which distributes the water to the residence or business. When it becomes necessary to replace a damaged, defective or deteriorated water shutoff valve  23  of one of the residences or businesses served by the main water line typically due to leakage of the valve  28 , water flow to all of the residences or businesses typically is temporarily terminated by means of crimping or freezing the main water line, or otherwise terminating water flow through the water line. The pressure flow stop of this invention, generally illustrated by reference numeral  1 , is designed to temporarily terminate water flow from the water source pipe  30  to the water shutoff valve  23  in order to facilitate replacement of the water shutoff valve  23 . Accordingly, termination of water flow in the main water line and interruption of water service to other residences or businesses served by the main water line is unnecessary.  
         [0025]    Referring next to FIGS.  1 - 6 ,  12  and  13  of the drawings, the pressure flow stop  1  of this invention includes an elongated, rigid, tubular inflation shaft  2 , typically constructed of steel aluminum or brass, in non-exclusive particular. An O-ring collar  4 , provided with a pair of adjacent O-ring grooves  4   a,  as illustrated in FIGS. 12 and 13, is mounted on the inflation shaft  2 , and a pair of  0 -rings  5  is seated in the respective O-ring grooves  4   a,  in spaced-apart relationship with respect to each other. As illustrated in FIG. 3, the front end of the inflation shaft  2  terminates in pneumatic communication with a male element  8  of a split-housing check valve  15 , fitted with a lock tab  8   a.  In application of the pressure flow stop  1  as hereinafter further described, the male element  8  of the split-housing check valve  15  is removably inserted in a companion female element  12  of the split-housing check valve  15 , fitted in pneumatic communication with a flexible, typically plastic, jointed metal or rubber, tubular balloon stem  6  typically by means of a compression fitting  11 , as illustrated in FIG. 4. Accordingly, when the male element  8  is coupled to the female element  12  of the check valve  15 , the check valve  15  allows bidirectional flow of air between the inflation shaft  2  and the balloon stem  6 , whereas the female element  12  prevents backflow of air from the balloon stem  6  through the female element  12  of the check valve  15  when the male element  8  is uncoupled from the female element  12  of the check valve  15 , as hereinafter described. A rubber balloon  13  is fitted on the front end of the balloon stem  6 , in pneumatic communication therewith typically by means of a compression fitting  14 . The inflation shaft  2  and balloon stem  6  of the pressure flow stop  1  are slidably mounted in the housing interior  16   c  of an elongated, typically cylindrical shaft housing  16 , typically constructed of polyvinyl chloride (PVC). A typically ¾″ threaded, hex-headed coupling cap  17  is slidably mounted on the front end  16   a  portion of the shaft housing  16  for threadibly engaging the companion water meter coupling  24  (illustrated in phantom in FIG. 1) of the valve housing  27 , in application of the pressure flow stop  1  as hereinafter described. As illustrated in FIG. 5, the front arm  34   b  of a housing T-fitting  34 , having a rear arm  34   a,  a middle arm  34   c  and a T-fitting interior  42 , receives the rear end  16   b  of the shaft housing  16 , the purpose of which housing T-fitting  34  will be hereinafter described. As further illustrated in FIG. 5, an insert  43 , having a central shaft opening (not illustrated), is inserted in the rear arm  34   a  of the housing T-fitting  34 , and the housing shaft  2  slidably extends through the central shaft opening (not illustrated) of the insert  43 . A valve body  35  is provided on the upward-standing middle arm  34   c  of the housing T-fitting  34 , in pneumatic communication with the T-fitting interior  42 . As illustrated in FIGS. 1 and 2, a flow valve  45 , provided with a flow valve handle  45   a,  extends from the valve body  35 , and a stem valve  36 , fitted with a stem valve handle  36   a,  further extends from the valve body  35 , opposite the flow valve  45 . The valve body  35  is typically provided with an air pressure indicator dial  39  to indicate the pressure of air flowing from the stem valve  36  through the valve body  35 , as hereinafter further described. Hose connectors  41  and  41   a  extend from the flow valve  45  and from the rear end of the inflation shaft  2 , respectively, as illustrated in FIGS. 1 and 2, and a pneumatic hose  40  establishes pneumatic communication between the flow valve  45  and the inflation valve  37 , through the respective hose connectors  41  and  41   a.  An inflation valve  37 , fitted with an inflation valve handle  38 , is mounted in the pneumatic hose  40 , adjacent to the hose connector  41   a.  Accordingly, as illustrated in FIG. 6, an air pump  32  can be coupled to the stem valve  36  to facilitate flow of air through the valve body  35  and into the T-fitting interior  42  of the housing T-fitting  34  and into the housing interior  16   c  of the shaft housing  16 , where the pressure of the flowing air impinges against the rear face  4   c  of the O-ring collar  4  to slide the inflation shaft  2  forwardly in the housing interior  16   c  and advance the balloon  13  through the water shutoff valve  23  and into the water source pipe  30 , in typical application of the pressure flow stop  1  as hereinafter farther described. In that case, a cylindrical lock sleeve  3 , traversed by a longitudinal shaft groove  3   a,  may be fitted on the inflation shaft  2  between the insert  43  of the housing T-fitting and the hose connector  41  on the inflation shaft  2  to space the hose connector  41  from the insert  43  and limit the depth of insertion of the balloon  13  in the water source pipe  30 , as hereinafter further described. Alternatively, upon opening of the inflation valve  37  by selective operation of the inflation valve handle  38 , air flows from the air pump  32 , through the stem valve  36 , the valve body  35 , the flow valve  45 , the pneumatic hose  40 , the inflation valve  37  and finally, through the balloon stem  6  and into the balloon  13  to inflate the balloon  13 , which blocks the water source pipe  30  against water flow through the water shutoff valve  23 .  
         [0026]    Referring again to FIGS. 1 and 5 and to FIGS.  6 - 11  of the drawings, in typical application the pressure flow stop  1  of this invention is capable of temporarily blocking water flow from the water source pipe  30 , attached to a main water line (not illustrated), to a damaged, defective or deteriorated water shutoff valve  23  of a business or residence, in order to facilitate replacing the water shutoff valve  23 . Accordingly, the valve  28  of the water shutoff valve  23  is initially closed in order to halt flow of water from the water source pipe  30  into the water meter coupling  24  of the valve housing  27  and attached water meter (not illustrated, threadibly attached to the water meter coupling  24 ). The water meter is next unthreaded from the water meter coupling  24 , and the threaded coupling cap  17  of the shaft housing  16  is caused to threadibly engage the water meter coupling  24 , as illustrated in FIG. 1. It will be appreciated by those skilled in the art that a 1″ or other size adaptor (not illustrated) can be threaded on the typically ¾″ threaded coupling cap  17  to fit the water meter coupling  24  of the valve housing  27 , as needed. It is further understood that a conventional threaded adaptor (not illustrated) can be provided on the shaft housing  16  instead of the coupling cap  17  for removably attaching the shaft housing  16  to the water meter coupling  24 . The inflation valve  37  of the pressure flow stop  1  is closed by pivoting the inflation valve handle  38  to extend from the inflation valve  37 , and the valve  28  of the water shutoff valve  23  is opened, such that water flows under pressure from the water source pipe  30 , through the valve housing  27  of the open water shutoff valve  23  and into the housing interior  16   c  of the shaft housing  16 , where the water pushes against the front face  4   b  of the O-ring collar  4  and advances the inflation shaft  2  rearwardly through the shaft opening (not illustrated) of the insert  43 . With the inflation shaft  2  coupled to the balloon stem  6  at the split-housing check valve  15  and the inflation shaft  2  extended from the insert  43  of the housing T-fitting  34 , as illustrated in FIG. 5, the lock sleeve  3  is fitted on the inflation shaft  2  by inserting the inflation shaft  2  in the longitudinal shaft groove  3   a  of the lock sleeve  3 , as illustrated in FIG. 1. The air pump  32  (coupled to the pressure flow stop  1  at the stem valve  36 ) is operated to cause pressurized air to flow through the valve body  35 , the T-fitting interior  42  of the housing T-fitting  34  and into the housing interior  16   c  of the shaft housing  16 , where the pressurized air impinges against the rear face  4   c  of the O-ring collar  4  and advances the inflation shaft  2  forwardly through the housing interior  16   c  and slides the inflation shaft  2  forwardly through the shaft opening (not illustrated) in the insert  43  of the housing T-fitting  34 . The O-rings  5 , seated in the O-ring grooves  4   a  (FIG. 13) of the O-ring collar  4 , form a water-tight seal between the T-fitting interior  42  and the open valve  28  of the water shutoff valve  23 , as illustrated in FIG. 5. The pressurized air in the housing interior  16   c  continues forward advancement of the inflation shaft  2  in the housing interior  16   c  until the deflated balloon  13  traverses the valve housing  27  of the open water shutoff valve  23  and finally, enters the water source pipe  30  as illustrated in FIG. 6. Advancement of the balloon  13  in the water source pipe  30  is halted when the lock sleeve  3 , fitted on the inflation shaft  2  at the shaft groove  3   a  (FIG. 1) as heretofore described, becomes interposed between the hose connector  41   a  at the rear end of the inflation shaft  2  and the rear end of the insert  43  of the housing T-fitting  34 . In the case of the L-shaped valve housing  27  illustrated in FIG. 9, the flexible balloon stem  6  bends downwardly and enters the water line coupling  25  of the valve housing  27  as the advancing balloon  13  engages the water line coupling  25  interior. As the deflated balloon  13  advances from the housing interior  16   c  of the shaft housing  16 , through the valve housing  27  and into the water source line  30 , pressurized water flows from the water source fine  30 , through the valve housing  27  of the open water shutoff valve  23  and into the housing interior  16   c  of the attached shaft housing  16 , and is prevented from flowing past the O-ring collar  4  by operation of both O-rings  4  of the O-ring collar  4 , located between the water shutoff valve  23  and T-fitting interior  42  of the housing T-fitting  34  as illustrated in FIGS. 5 and 6. It will be appreciated by those skilled in the art that the air pressure exerted against the rear face  4   c  of the O-ring collar  4  in the housing interior  16   c  of the shaft housing  16  overcomes the opposing water pressure against the front face  4   b  of the O-ring collar  4  to facilitate forward advancement of the inflation shaft  2  agape the water pressure. It will be further appreciated by those skilled in the art that the rigid inflation shaft  2  reinforces the flexible balloon stem  6  against water pressure as the balloon stem  6  is advanced through the valve housing  27  and water source pipe  30  and pressurized water flows from the valve housing  27  into the housing interior  16   c  of the shaft housing  16 . Once it is positioned in the water source pipe  30  as illustrated in FIGS. 6 and 9, the balloon  13  is inflated by opening the inflation valve  37  by pivoting the inflation valve handle  38  to lie flat against the inflation valve  37 . This causes pressurized air from the air pump  32  to flow through the flow valve  45 , pneumatic hose  40 , open inflation valve  37 , inflation shaft  2 , balloon stem  6  and finally, into the balloon  13 , since the air pressure in the alternative air flow pathway provided by the T-fitting interior  42  and housing interior  16   c , due to the stationary position of the O-ring collar  4  in the housing interior  16   c , imparted by the lock sleeve  3 , exceeds the air pressure in the pneumatic hose  40 , inflation shaft  2 , balloon stem  6  and balloon  13 . The balloon  13  continues to inflate until the inflating balloon  13  substantially obstructs the interior of the water source pipe  30  and blocks further flow of pressurized water from the main water line and water source pipe  30 , into the valve housing  27  of the open water shutoff valve  23 . While the inflated balloon  13  remains lodged in the water source pipe  30 , the inflation valve  37  is closed by extending the inflation valve handle  38  from the inflation valve  37 , and this action terminates inflation of the balloon  13  in the water source pipe  30 . The shaft housing  16  is next unthreaded from the valve housing  27  at the coupling cap  17  and the inflation shaft  2  is uncoupled from the balloon stem  6  by lifting the lock tab  8   a  (FIG. 3) of the male element  8  of the split-housing check valve  15  and removing the male element  8  from the female element  12  of the split-housing check valve  15 . Consequently, the female element  12  of the split-housing check valve  15  pneumatically seals the balloon stem  6  such that the balloon  13  remains inflated and sealed in the water source pipe  30 , as illustrated in FIGS. 7 and 10. The damaged, deteriorated or defective water shutoff valve  23  is unthreaded from the water source pipe  30  and pulled from the check valve  15  end of the balloon stem  6  as the balloon  13  remains inflated in the water source pipe  30 , as illustrated in FIGS. 8 and 11. As the water source pipe  30  remains obstructed by the inflated balloon  13 , a replacement water shutoff valve  23  is slipped on the check valve  15  end of the balloon stem  6  by inserting the female element  12  of the split housing check valve  15  in the water line coupling  25  and out of the water meter coupling  24  of the replacement water shutoff valve  23 , as the replacement water shutoff valve  23  is slided on the balloon stem  6 , and the water line coupling  25  of the water shutoff valve  23  is threaded on the water source pipe  30 , as illustrated in FIGS. 7 and 10. The inflation shaft  2  is again pneumatically coupled to the balloon stem  6  by inserting the male element  8  of the check valve  15  into the female element  12  of the check valve  15  and locking the lock tab  8   a , and this opens the check valve  15  and enables flow of air from the balloon stem  6  into the housing shaft  2 . The shaft housing  16  of the pressure flow stop  1  is next threaded on the water meter coupling  24  of the replacement shutoff valve  23 , as illustrated in FIGS. 6 and 9, by operation of the coupling cap  17 . After the inflation valve  37  is again opened by pivoting the inflation valve handle  38  to lie against the inflation valve  37 , the balloon  13  is deflated in the water source pipe  30  by depressing the stem (not illustrated) of the pneumatic stem valve  36  (provided on the valve body  35 ), and this action unblocks the water source pipe  30  and allows the pressurized water in the water source pipe  30  to flow from the water source pipe  30 , through the valve housing  27  of the open replacement water shutoff valve  23  and into the housing interior  16   c  of the shaft housing  16 , where the pressurized water pushes rearwardly against the front face  4   b  of the O-ring collar  4  and slides the inflation shaft  2  rearwardly in the housing interior  16   c . The flowing water further pushes the deflated balloon  13  from the water source pipe  30 , through the open replacement water shutoff valve  23  and into the housing interior  16   c  of the shaft housing  16 , as the inflation shaft  2  extends from the central shaft opening (not illustrated) of the insert  43 . The replacement water shutoff valve  23  is next closed to prevent further flow of water from the water source pipe  30  and replacement water shutoff valve  23 . Finally, the shaft housing  16  is unthreaded from the water meter coupling  24  of the replacement water shutoff valve  23 , the water meter (not illustrated) is threaded on the water meter coupling  24  of the replacement water shutoff valve  23  and the valve  28  of the water shutoff valve  23  is opened, respectively, in order to re-establish flow of water from the main water line to the residence or business serviced by the water source pipe  30 .  
         [0027]    It will be appreciated by those skilled in the art that the pressure flow stop of this invention is simple in design and operation and eliminates the necessity of terminating supply of water to multiple residences or businesses served by a main water line, under circumstances in which it is necessary to replace the water shutoff valve of one of the residences or businesses served by the main water line. The pressure flow stop  1  can be constructed in a variety of sizes in order to facilitate replacement of water shutoff valves having various sizes. While the balloon stem  6  is typically constructed of flexible plastic, it is understood that it can be constructed of any elongated, water-tight tubular flexible material, including rubber or a jointed or segmented metal tube. Moreover, it is understood that any suitable pressurized fluid can be introduced into the inflation shaft  2  in order to inflate the balloon  13 , according to the knowledge of those skilled in the art.  
         [0028]    While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications can be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.