Abstract:
The invention is an improved conduit flow controller for selectively controlling the flow of fluid through an elongated conduit. The conduit has an aperture defined by a continuous peripheral edge in the sidewall of the conduit. An elongated housing surrounds the aperture and is sealingly connected to the conduit. A conduit stopper is movably mounted in the housing and is positionable in the conduit. The conduit stopper includes a deformable sealing element having opposed flat sides and an edge engageable with the conduit. A carrier is sealingly connected with the sealing element. A resilient seal is mounted on a carrier and is engageable with the continuous edge. The sealing element is cooperative with the seal to close a portion of the conduit to regulate the flow of fluid along the elongated conduit.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of provisional application Ser. No. 60/082,644, filed Apr. 22, 1998, titled, “Conduit Flow Controller.” 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an improved conduit stopper, used in pressurized conduit. The stopper is comprised of a solid, rigid carrier with two bendable forks that contain a deformable, flat sealing element. The external cylindrical surface of each fork is covered with a resilient sleeve member. The sealing element and resilient member cooperate in effecting sealing engagement with each other and with the interior surfaces of the conduit and with the cylindrical surface of the periphery of an access port that was cut into the conduit during a previous pressure tapping procedure. This improved conduit stopper design can be used in both temporary and permanent stopper installations, which is not true of any prior art device. 
     2. Description of the Prior Art 
     Pressurized conduit or piping systems convey fluids, both liquid and gas, in municipalities, industrial plants, and commercial installations. When originally installed, these conduit systems included certain block valves that could be closed to isolate sections of the conduit for repairs, relocation, or installation of new components into the conduit. 
     When such shutdowns are required in municipal distribution systems, it is frequently determined that too large an area will be deprived of water or gas service. Schools, hospitals, food processors, and commercial and industrial facilities may have to be shut down. 
     The total length of conduit to be depressurized can be greatly shortened by using one or more conduit stoppers, often in conjunction with existing block valves. A conduit stopper is a device that can be inserted into a pressurized conduit without prior service interruption, and the volume of fluids to be wasted is greatly reduced. Upon completion of work on the depressurized conduit, the stoppers are retracted from the conduit and block valves are opened, restoring flow through the repaired section of conduit. 
     Conduit stoppers are very well known in prior art under a variety of names, such as line stop, conduit stopper, conduitline plugger, inserting valve, add-on valve, insertable stopper valve, etc. Regardless of variation in construction, all conduit stoppers share one primary feature: the stopper is installed into a chamber adjacent to and communicating with the pressurized conduit. In most cases the chamber is a cylindrical nozzle that is assembled perpendicular and pressure-tight to the outside of the conduit. Communication is established by a process called pressure tapping. This process is well known in prior art, and utilizes a temporary tapping valve to allow different machines and apparatus to be mounted onto the conduit without loss of fluid pressure of flow. 
     The conduit stopper can then be installed through the valve into the nozzle chamber, where it is held until the conduit must be plugged. To stop flow in said conduit, the stopper is then moved from the nozzle into the conduit. 
     Many conduit stoppers use a solid, cylindrical, deformable plug, which engages in sealing contact with the inner walls of the conduit and the nozzle and with the cylindrical cut surface of the access port in the conduit. If such a deformable plug is unsupported, as is disclosed by Long: U.S. Pat. No. 3,799,182, the upstream fluid pressure capability rating of the stopper will be low, because increased pressure will further deform the unsupported plug into a failure shape that will allow leakage past the stopper, as taught by Murphy, et al: U.S. Pat. No. 5,690,139. With some rigid internal support, as taught by Thomas: U.S. Pat. No. 4,369,813, the pressure rating of the stopper is increased. 
     Higher stopper pressure ratings are attainable by providing substantial upstream and downstream external supports to a central, generally flat, deformable sealing member, as taught by Witt: U.S. Pat. No. 2,272,734; Lee: U.S. Pat. No. 2,789,244; Van Epps, et al: U.S. Pat. No. 3,115,163; and Murphy, et al: U.S. Pat. No. 5,186,199. However, as above disclosed, flat, deformable members, when acting alone, cannot totally pressure seal the conduit. Leakage flow passes vertically into the communicating nozzle chamber, because the thickness of the central sealing member does not fully close the area of the access port cut by the pressure tap. 
     Witt: U.S. Pat. No. 2,272,734 taught bendable metal carrier forks to sealingly contact the upstream and downstream cylindrical surfaces that were cut into the upper conduit metal wall during the pressure tap. The solid geometry was incorrect, precluding tight metal-to-metal seals. Lee: U.S. Pat. No. 2,789,244 taught a thick, cylindrical extension of the flat, central seal, which extension was deformed in the intersection between the conduit and the nozzle, thereby pressure sealing said intersection and blocking all flow and upstream fluid pressure. 
     Van Epps, et al: U.S. Pat. No. 3,115,163 disclosed a circumferential shoulder in each fitting nozzle to seal against a resilient, segmented O ring-type seal contained on each movable, rigid, stopper carrier fork. This segmented seal of the Van Epps improvement proved to be very fragile in the field, which resulted in frequent bypass leakage around the central flat sealing element. The Murphy, et al: U.S. Pat. No. 5,186,199 improvement restricted the downward force applied onto the segmented carrier seal, thereby increasing seal life. 
     Use of the nozzle shoulder presents both operational and logistical problems. The vertical location of the shoulder in each nozzle is critical in order to obtain simultaneous sealing action by both the flat central sealing element and the segmented “O” ring members. Specific vertical location of the sealing shoulder in each nozzle must be determined by the exact bore and wall thickness of the specific conduit into which the stopper nozzle is to be inserted. 
     Within any given nominal conduit size, for instance 8-inch, there may be more than 10 combinations of wall thickness and conduit outer diameter. Outer diameter of existing conduits can be determined either from records or by inspection. However, in emergency situations wall thickness is often unknown. Nozzles with improper shoulder locations are frequently installed, resulting in excessive leakage past the stopper. 
     The present invention totally eliminates the sealing shoulder in the nozzles of all fittings, thereby allowing shutdown using a single nozzle size for the full range of dimensional variation found in any given nominal conduit size. 
     Most conduit stoppers are intended for temporary service, often in emergency situations. When work is completed on the depressurized conduit, the temporary stopper is retracted, and the apparatus and tapping valve are removed under pressure and without interruption of service. The stopper fitting on the conduit is then protected with a closure device. The process can later be repeated under full fluid pressure using the original fitting. 
     Other conduit stoppers, such as Thomas: U.S. Pat. No. 4,369,813 and Long: U.S. Pat. No. 3,799,182, are designed specifically for permanent installation into a pressurized conduit. Each permanent conduit stopper is provided with an internal jackscrew-type actuating means that allows the conduit stopper to be operated as a conventional block valve that is opened and closed by a worker by merely turning a handle or a valve wrench. This type of permanent stopper can be used in emergencies in the same manner as a temporary stopper and then abandoned. However, the fitting material cost is considerably higher because of the self-contained jackscrew actuators. The present invention allows a temporary conduit stopper to later be converted into a permanent embodiment under pressure and with interruption of flow. The designs of prior art temporary conduit stoppers preclude later conversion without shutdown into permanent configurations. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial cross-sectional elevational view with a cross-sectional view through a pressurized conduit with installation apparatus mounted on A temporary stopper fitting secured to the conduit; 
     FIG. 1 is an enlarged fragmentary view of the actuator assembly, which is the upper portion of the apparatus of FIG. 1; 
     FIG. 3 is an enlarge fragmentary cross-sectional view of an installation housing connected to the actuator of FIG. 2, being part of the installation apparatus of FIG. 1; 
     FIG. 4 is an enlarged fragmentary cross-sectional view of a flanged nozzle assembly and valve mounted on the conduit and connected to the installation housing of FIG. 3, being a portion of the apparatus shown in FIG. 1; 
     FIG. 5 is an enlarged view of a temporary stopper plug; 
     FIG. 6 is a cross-sectional view of the stopper plug taken on Line  6 — 6  of FIG. 5; 
     FIG. 7 is an enlarged cross-sectional view taken on Line  7 — 7  of FIG. 4, showing a saddle and nozzle mounted on the conduit of FIG. 1; 
     FIG. 8 is an enlarged cross-sectional view taken on Line  8 - 9  of FIG. 4, showing a portion of a cut in the conduit of FIG.  1  and showing the interrelationship of the saddle and nozzle; 
     FIG. 9 is an enlarged cross-sectional view taken on Line  9 — 9  of FIG. 7, showing a saddle mounted on the conduit and positioning of a nozzle relative to an aperture in the conduit; 
     FIG. 10 is an enlarged cross-sectional view similar to FIG. 4 but showing a temporary stopper plug sealingly engaged in the conduit; 
     FIG. 11 is an enlarged cross-sectional view similar to FIG. 8, showing the temporary stopper plug of FIG. 10 mounted in the conduit in sealing engagement therewith to close off flow through the conduit; 
     FIG. 12 is an enlarged cross-sectional view taken on Line  12 — 12  of FIG. 11; 
     FIG. 13 is an enlarged cross-sectional view taken on Line  13 — 13  of FIG. 11; 
     FIG. 14 is an enlarged cross-sectional view taken on Line  14 — 14  of FIG.  11  and being an enlargement of the temporary stopper positioned in sealing engagement with the conduit; 
     FIG. 15 is an enlarged fragmentary perspective view with portions broken away, showing areas in which the stopper members co-operate and sealingly engage the conduit; 
     FIG. 16 is a cross-sectional view of a temporary stopper fitting with a completion plug and a closure flange; 
     FIG. 17 is a cross-sectional elevational view similar to FIG. 1 but showing an installation apparatus with a permanent conduit stopper mounted in an installation housing mounted on a conduit; 
     FIG. 18 is an enlarged fragmentary cross-sectional view of an actuator portion of the apparatus of Fib.  17 ; 
     FIG. 19 is an enlarged partial cross-sectional view of an installation housing of the permanent stopper apparatus of FIG. 17 with a permanent conduit stopper positioned therein; 
     FIG. 20 is an enlarged fragmentary cross-sectional view of a flanged nozzle assembly shown in FIG. 17 mounted on the conduit; 
     FIG. 21 is an enlarged fragmentary cross-sectional view similar to FIG. 20 but showing a permanent stopper sealingly secured in the flange of the nozzle assembly; 
     FIG. 22 is an enlarged fragmentary cross-sectional view showing a final assembly for the permanent conduit stopper with a plugging head in an open position; 
     FIG. 23 is an enlarged fragmentary cross-sectional view taken on Line  23 — 23  of FIG. 22, showing a completion plug retained in position by lock screws and showing a portion of an “O” ring seal; 
     FIG. 24 is a cross-sectional view taken on Line  24 — 24  of FIG. 22, showing a carrier crown with opposed keys mounted in keyways in the nozzle; 
     FIG. 25 is a cross-sectional view taken on Line  25 — 25  of FIG. 22, showing positioning of a relaxed deformable flat sealing element within a plugger carrier; 
     FIG. 26 is an enlarged fragmentary elevational view taken on Line  26 — 26  of FIG. 20, showing a keyway and a chamfer keyway entrance; 
     FIG. 27 is an enlarged cross-sectional view showing the permanent stopper in a closed attitude to seal flow through the conduit; and 
     FIG. 28 is similar to FIG. 24, except showing an alternate construction for the keys and keyways. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Conduit stoppers are commonly used to block the flow of fluids through conduits. A temporary conduit stopper is commonly used in emergency situations when it is necessary to interrupt the flow through a conduit immediately for a prescribed period of time, after which the stopper is removed from the conduit. In other cases, it is found that it is desirable to provide a means to block flow through the conduit intermediately. This control is accomplished by the utilization of a permanent conduit stopper, which remains attached to the conduit and can be operated in a manner similar to a block valve that was installed in the original conduit system. In the case of both conduit stoppers, each provides a means to effect complete interruption of flow. It is also desirable to be able to utilize the same equipment for placing a permanent valve in a conduit as for providing a temporary stopper for the conduit. 
     Irrespective of whether there will be a permanent or temporary conduit stopper installed onto a conduit, it is necessary to make an opening in the conduit. The apparatus and method for cutting an opening in a conduit and removing the coupon is well known and understood in the art. A typical apparatus and method are disclosed in U.S. Pat. No. 3,799,182, entitled, “Add-on Stopper Valve for Existing Piping”, the inventor being George M. Long. 
     Referring now to FIG. 1, a nozzle assembly, generally indicated by numeral  36 , is sealingly mounted on a conventional pressurized elongated conduit or conduit  32  having an access port or aperture  34  formed therein. A stopper machine, generally indicated by numeral  30 , is sealingly mounted on nozzle  36 . A temporary tapping valve  38 , part of the stopper machine, is next mounted on nozzle assembly  36 . An installation housing  40  is mounted on valve  38 . An actuator apparatus  42  is a conventional jackscrew in this instance, though a hydraulic cylinder may be used instead. The actuator  42  is mounted on installation housing  40 . A temporary conduit stopper assembly  44  is connected to an actuator rod  122  and is shown positioned in installation housing  40 . 
     Nozzle assembly  36  includes an elongated housing or nozzle  46 , the inner diameter of which is the same or greater than the inner diameter of conduit  32 . Nozzle  46  is connected to a saddle assembly  48 , as may be best seen in FIG.  4 . The saddle assembly includes a lower portion  50  and an upper portion  52 . The lower portion has a pair of elongated ears  54  and  56 , which extend along the length of the lower portion  50  of the saddle. The upper portion  52  includes a pair of elongated ears  58  and  60 , which are positioned adjacent to the ears  54  and  56 , respectively. Conventional bolts and nuts  62  secure ears  54  and  56  to ears  58  and  60 , respectively. A saddle gasket  64  is mounted on the conduit  32  in contact with upper portion  52  of the saddle. Gasket  64  surrounds aperture  34  to provide a leak-proof seal around the aperture. Nozzle  46  extends upward substantially perpendicular to the longitudinal axis of the conduit. The nozzle has an integral nozzle flange  66  extending outward therefrom. Flange  66  has a plurality of radial lock screw threaded openings  67 , which extend radially from the exterior of the flange to the interior of the nozzle. A completion plug lock screw  69  is threadedly mounted in each of openings  67 . Each lock screw has a nose  71  formed therein. A pipe plug  73  is mounted on the outer end of each of the openings  67  to seal closed the opening. 
     Cylindrical access port or aperture  34  is cut into the top of the conduit by a pressure tapping process, described hereinafter. The diameter of the aperture defined by a continuous edge  35  is slightly less than the inner diameter of conduit  32 . Referring now to FIGS. 7,  8 , and  9 . It may be seen that the portion of the cut that is at the top of the conduit, as may be best seen in FIG. 9, has the least thickness of pipe exposed, while the portion of the cut made through the pipe side, close to the horizontal center of the pipe has a greater thickness of the pipe cut exposed, as shown in FIG.  8 . Thus, the continuous edge portion of the pipe defining the cut, which is substantially perpendicular to the axis of the pipe, has a smaller face than that portion of the cut face that is substantially parallel to the axis of the pipe. It follows that there is a gradation in the surface area of the pipe defining the access opening from the upper portion to that portion that is adjacent to the center. 
     Referring back to FIG. 4, the temporary tapping valve  38  is of a conventional gate type and well known in the art. The valve includes a valve body  68  having a flange  70  formed integral therewith and sealingly secured to nozzle flange  66  by conventional nuts and bolts  72 . Valve  38  includes a conventional gate  74 , which is controlled through a cranked handle  76 , to move inside a slot  78  in the valve body to control the flow of a fluid through the valve. The valve body  68  has an upper flange  80  formed integral therewith to connect the valve to the installation housing  40 . 
     As may be seen in FIG. 3, installation assembly  40  includes an elongated tubular cylinder  82  with a lower flange  84  formed integral therewith. Flange  84  is sealingly connected to flange  80  by a plurality of conventional nuts and bolts  86 . The installation housing has an upper flange  88  formed integral with its upper end. A flanged dome  90  has a connecting flange  92 , which is sealingly connected to flange  88  of the installation housing. The actuator is connected to the installation housing through a pair of tie rods  94  and  96 , which also serve to secure flanges  88  and  92  in a sealing relationship. 
     Referring now to FIG. 2, tie rods  94  and  96  are also connected to each other at their upper ends by a thrust plate  98 . The thrust plate has an internally threaded aperture  100  that receives a conventional actuator screw  102  with a tee handle  104  mounted through its upper end. The actuator screw has a threaded collar  106  mounted on its lower end with a lock nut  108  locking the threaded collar to the actuator screw. A conventional thrust bearing  110  connects collar  106  with the lower end of actuator screw  102 . A tee pin  112  has a head  114  in engagement with thrust bearing  110  and with a thrust washer  116 . The collar  106  contains an aperture  118  through which extends a column  120  of the tee pin. Threaded collar  106  is free to rotate relative to tee pin  112 . Actuator rod  122  includes a column receptacle  124 , which receives column  120  of the tee pin. Column  120  contains detent aperture  126 , which receives a detent pin  128  to secure the tee pin to the actuator rod  122 . The actuator rod has a circular cross section, except for a pair of wrench flats  130  to provide a convenient means for rotating the actuator rod as needed. 
     A guide yoke  132  is secured to the actuator rod. The guide yoke has a pair of tie rod slots  134  and  136 , which slidably receive tie rods  94  and  96 , respectively. The yoke includes a guide hub  138 . A rod aperture extends through the guide hub and receives actuator rod  122 . A plurality of set screws  142  is mounted in guide hub  138  and engage the actuator rod to secure the actuator rod to the guide hub and thereby prevent the actuator rod from rotating once the set screws are tightened. As shown in FIG. 3, the actuator rod  122  extends through flanged dome  90  with a seal  144  in sealing engagement with the actuator rod. The actuator rod is connected to the plug hold assembly  146 . 
     Nozzle assembly  36  is mounted pressure-tight onto the pipe  32 . A conventional cylindrical shell cutter is advanced from a well known cutting machine (not shown here), through the open valve, to form the cylindrical access port or aperture  34 . The outside diameter of the shell cutter is slightly less than the interior diameter of the conduit  32 . The severed portion of pipe to form access port  34  called a coupon. The coupon is retained inside the shell cutter and is extracted through the nozzle  46  and valve  38 , as is well known in the art. Gate  74  is closed and the cutting apparatus is disengaged from the valve. 
     The stopper assembly  44  is aligned within the installation housing  40 . The guide yoke set screws  142  are tightened to prevent the actuator rod from rotating in the yoke, thereby maintaining stopper alignment with the conduit. 
     The installation housing  40  and actuator apparatus  42  are assembled pressure-tight onto valve  38 . Valve  38  is opened, and the actuator screw is rotated clockwise to lower actuator rod  122  and stopper  44  through the valve and into nozzle  46 . The stopper is then held in the nozzle until conduit shutdown is required. 
     Referring the FIG. 3, conduit stopper  44  is attached to a carrier holder  146 , which consists of a hold hub  147  and a holder flange  150 . The actuator rod  122  is secured to the hub  147  by a conventional nut and bolt  148 , which prevents rotation between the rod and the holder. A vertical stud  149 , integral with flange  150 , threadingly engages with an internally threaded receptacle  151  in hub  147 . The flange  150  is secured to a carrier which has a crown  152 . A pair of conventional bolts  154  engage internally threaded openings  153  in the top of carrier crown  152 . As best seen in FIGS. 5 and 12, the crown is connected to a pair of bendable arms or forks  156  and  158 . Fork  156  includes an outer web  160  and an inner web  162 . Fork  158  includes an outer web  164  and an inner web  166 . Inner web  162  includes an internally threaded aperture  168 , which receives a carrier fork bolt or arrester  170 , which is rotatably mounted in inner web  166  and threadedly mounted in receptacle aperture  168  to limit the spacing between the forks. Outer web  164  contains a plug aperture  172  that allows access to bolt  170 . The aperture is closed by a removable sealing plug  174 . Spacer collar  161  maintains minimum distance between forks. 
     Referring to FIGS. 5 and 6, the forks  156  and  158  terminate in hemispherical bottoms  176  and  178 , respectively. Deformable sealing element or paddle  180  is mounted between the arms  156  and  158 . The element has an arcuate bottom  182  for engagement with pipe  32 . A resilient sheet  184  is bonded to arm  156 , and a resilient sheet  186  is bonded to arm  158 . The sheets  184  and  186  provide a resilient seal for the carrier. The space between sheets  184  and  186  is filled by deformable sealing element  180 . As may be seen in FIG. 6., element  180  has a pair of imbedded threaded retainer plugs  188  therein. Retainers  188  are connected to conventional bolts  190 , which are mounted in crown  152 . Shims  192  are selectively positioned between the crown and the paddle to allow the element to be adjusted relative to the crown. The deformable sealing element contains a recess  194  opening to the crown. The recess contains a rigid protective tube  195  to prevent inward deformation during the sealing operation. Sealing element  180  includes a vertical slit  173  that passes through the body of the element and joins an opening  169  for the fork bolt  170  and an opening  165  and  162  at each end of the slit to prevent tearing of the sealing element during sealing deformation. 
     Referring now to FIGS. 1 and 12, clockwise rotation of the tee handle  104  forces the plug downward through open valve  38  and nozzle assembly  36 , then through access port  34 , so that the stopper enters conduit  32 . As the stopper enters port  34 , chamfers  196  on the ends of resilient sheets  184  and  186  facilitate entry of the resilient sheets into the opening. Movement of the stopper through the opening causes sealing element  180  to engage the bottom half of the pipe. As the carrier crown  152  is moved toward the pipe and the sealing element engages the pipe, the resilience of the element causes it to spread. The sealing element expands outward and pushes arms  156  and  158  away from each other. Carrier fork bolt head  171  is spaced from inner web  166  so that the forks can bend apart. The resilient surfaces on the forks engage portions of the cut surface of the pipe. The upper portion  34  of the conduit, as may be seen in FIG. 9, has a smaller cut surface than the portion of the conduit adjacent to the pipe wall, which is near the center of the pipe, as seen in FIG.  8 . The flow of fluid in the conduit pushes the stopper toward the downstream side, so that there is engagement of the resilient sheet with the cut edge of the pipe  175 , as shown in FIGS. 11,  13 ,  14 , and  15 . The maximum force is at the top of the pipe, where there is the smallest amount of surface. 
     The deformation of the sealing element provides a dual function. As the deformable sealing element  180  expands, the forks are pushed outward to force the resilient sheet on the downstream side into secure sealing engagement with the cut edge of the pipe. The element also deforms radially in the conduit to engage in a sealing relationship with the broadest portion of the cut surface  163  and engage that portion of the interior of the pipe from the broadest portion down to the bottom of the conduit and upward on a side  157 . Thus, there is a seal of the downstream side of the conduit by the cooperation of the deformable sealing element and the resilient sheets, which form the resilient seal on the carrier. The flow of a fluid in the conduit is thereby regulated by the interaction of the conduit stopper  44  with the conduit to interrupt the flow of fluid. The locations of sealing interfaces  198  between the deformed sealing element and the resilient sheets are shown in FIGS. 11,  12 , and  15 . 
     As shown in FIGS. 11,  12 ,  14 , and  15 , the downward force from carrier crown  152  deforms sealing element  180  laterally into sealing contact with inner wall  157  of the pipe upward through the side portions of cut surface  163 . As shown in FIG. 13, the deformation of the sealing element creates lateral voids  179 ,  185 , and  187  between the sealing element and retainer plugs  188 , and the protective tube  195 , respectively. Slit  173  and clearance aperture  169  are deformed relative to carrier fork bolt  170 . 
     The present construction utilizes the resilient seal to engage the enlarged surface area of the cut at the lower portion of the cut in the pipe to effect a seal where the resilient sealing force applied by the fluid pressure in the pipe is reduced. 
     The temporary conduit stopper is readily removed simply by turning the actuator screw counterclockwise to raise the stopper through nozzle  46  and valve  38  into the installation housing and actuator are removed from the valve. The stopper assembly  44  is removed from the plug holder flange  150  by removing two bolts  154 . A completion plug  181 , which is shown in FIG. 16, contains a pressure-sealing “O” ring  199 . Plug  181  is installed onto holder flange  150  with bolts  154  that engage threaded receptacles  197  in the plug. The guide yoke set screws  142  are loosened, allowing rotation of the actuator rod  122  in the yoke aperture  140 . The holder flange  150  is threadingly engaged with holder hub  147 , which is still attached to the actuator rod  122 . 
     The housing and actuator are reinstalled onto the valve, and the valve is then opened. The pipe plugs  73  are removed from the periphery of the nozzle flange  66 , and the threaded lock screws  69  are retracted until the pin noses  71  are outward of the nozzle flange bore  77 . 
     By turning the actuator handle clockwise, completion plug  181  is lowered into nozzle flange  66  until the bottom of the plug contacts the nozzle shoulder  65 , which stops further downward movement. Lock screws  69  are then tightened into grooves  183  in completion plug  181 , thereby vertically securing the plug in the nozzle flange against the upward force of the fluid pressure. A pressure seal between the inner wall of the nozzle flange and the completion plug is accomplished by the “O” ring  199 . 
     A hand wrench is used to engage the wrench flats  130  on the actuator rod  122 . The wrench is sharply tapped in a counterclockwise direction to loosen the threaded engagement between the plug holder flange stud  145  and hub  147 . By turning the actuator rod  122  further counterclockwise, the holder hub and flange are separated. 
     Housing  40  and actuator are removed from the valve, and open valve  38  is removed from the nozzle flange  66 . The holder flange  150  is unbolted from the top of the completion plug  181 . A closure flange  191  with attached gasket is then mounted onto the nozzle flange with conventional bolts and nuts  72  to protect the installation. The temporary conduit stopper can later be reinstalled into the original fitting by reversing the sequence of operations. 
     A permanent conduit stopper is installed into a pressurized pipe using installation apparatus  200  shown in FIG.  17 . This installation apparatus is shown mounted on a conventional conduit or pipe  202  with an aperture  204  formed therein. The pipe  202  with the aperture  204  is identical to pipe  32  with access port  34  described above. A nozzle assembly  206  is sealingly mounted on pipe  202 . A temporary or tapping valve  208  is sealingly mounted on nozzle assembly  206 . Valve  208  is identical in construction to valve  38  described above. An installation housing  210  is mounted on valve  208 . An actuator assembly  212 , which in this instance is a conventional jackscrew, is mounted on installation assembly  210 . A permanent conduit stopper  214  is shown positioned in the installation housing  210 . 
     Referring to FIG. 20, nozzle assembly  206  includes a nozzle  216 , which is connected to a saddle assembly  218 . The saddle assembly  218  is substantially identical in construction to saddle assembly  48  described hereinabove. Saddle assembly  218  includes a lower portion  220  and an upper portion  222 . The lower portion has a pair of elongated ears  224  and  226 . The upper portion includes a pair of elongated ears  228  and  230 , which are positioned adjacent to ears  224  and  226 , respectively. Conventional bolts and nuts  232  secure the upper and lower portions  222  and  220  to each other. A saddle gasket  234  is mounted on pipe  202  in contact with the upper portion  222  or the saddle. Gasket  234  surrounds aperture  204  to provide a leak proof seal around the aperture. Nozzle  216  is elongated and generally tubular and extends upward substantially perpendicular to a longitudinal axis of pipe  202 . The nozzle has a nozzle flange  236  extending radially outward from the nozzle. Nozzle  216  includes an interior nozzle shoulder  238  adjacent to flange  236 . Keyways  240  and  242  are shown machined into opposed sides of the interior wall of the nozzle, extending to the shoulder. An alternate construction is shown in FIG.  28 . Each of the keyways has an enlarged chamfer opening  244 , which is best seen in FIG. 26 for keyway  242 . The chamfer facilitates the insertion of a key into the keyway. 
     Flange  236  has a plurality of radial lock screw threaded openings  246 , which extend axially from the exterior of the flange to the interior of the nozzle. A completion plug lock screw  248  is threadedly mounted in each of openings  246 . Each lock screw has a nose  250  formed therein. A pipe plug  252  is mounted on the outer end of each of the openings  246  to pressure seal the opening. 
     Opening  204  is identical to access port  34 , as also may be seen in FIGS. 21 and 22. The opening, as with port  34 , has the least thickness of pipe exposed where the cut is made into the pipe at the top of the pipe. The greater thickness of pipe is exposed at the sides, closer to the center of the pipe. Thus, there is a gradation of the surface area of the pipe, increasing from the upper portion of the pipe to that side portion that is adjacent to the center of the pipe. 
     The temporary tapping valve  208  is identical in construction to valve  38 . Valve  208  includes a valve body  254  having a flange  256  with gasket sealingly connected to nozzle flange  236  by a plurality of conventional nuts and bolts  258 . Valve  208  includes a conventional gate  260 , which is controlled by a crank valve  262 . Gate  260  moves along a slot  264  into the valve body to control the flow of fluid through the valve. Valve body  254  has an upper flange  266  that is formed integral therewith to connect the valve to installation housing  210 . 
     As shown in FIG. 19, installation housing  210  includes an elongated tubular housing  268  having a lower flange  270  formed integral therewith and sealingly secured to valve flange  266  by a plurality of conventional nuts and bolts  272 . The installation housing has an upper flange  274  formed integral with its upper end. A flanged dome  276 , identical to dome  90 , is sealingly connected to the installation housing by an integral flange  278 , which is connected to housing flange  274 . 
     As shown in FIG. 18, actuator  212  is identical in construction to actuator  42 . Actuator  212  is connected to installation housing  210  by a pair of tie rods  280  and  282 . Tie rods  280  and  282  serve to secure flanges  274  and  278 . The upper ends of the tie rods are connected to each other by thrust plate  284 . The thrust plate is identical in construction to thrust plate  98 . Thrust plate  284  has an internally threaded aperture  286  that receives a conventional actuator screw  288  identical in construction to actuator screw  102 . Actuator screw  288  has a tee handle  290  mounted in its upper end. The actuator screw has a threaded collar  292  mounted on its lower end, with a lock nut  294  locking the threaded collar to the actuator screw. A conventional thrust bearing  296  is mounted in collar  292  in engagement with the end of the actuator screw. A tee pin  298 , identical to tee pin  112 , has a head  300  in engagement with thrust bearing  296  and with a thrust washer  302 . The collar  292  contains an aperture  304  through which extends a column  306  of tee pin  298 . The threaded collar is free to rotate relative to tee pin  298 . Column  306  of the tee pin is connected to an actuator rod  308 . The actuator rod includes a column receptacle  310 , which receives column  306  of the tee pin. The column includes a detent aperture  312 , which receives a detente pin  314  to secure the tee pin to actuator rod  308 . Actuator rod  308 , like actuator rod  122 , has a circular cross section, except for a pair of wrench flats  316  to provide a convenient means for rotating actuator rod  308  as needed. 
     A guide yoke  318 , identical to guide yoke  132 , is secured to the actuator rod  308 . Guide yoke  318  includes a pair of tie rod slots  320  and  322 , which receive tie rods  280  and  282 , respectively. The yoke includes a guide yoke hub  324 . A rod aperture  326  extends through the guide yoke hub and receives actuator rod  308 . A plurality of set screws  328  is mounted in guide yoke hub  324  to secure the actuator rod  308  to guide yoke  318  and thereby prevent actuator rod  308  from rotating once the set screws are tightened. As shown in FIG. 19, actuator rod  308  extends through flanged dome  276 , with a pressure seal  330  in engagement with the actuator rod. Permanent conduit stopper  214  is threadingly connected to actuator rod  308  by a plug holder assembly  331 , which is identical to plug holder assembly  146 . Plug holder hub  332  is secured to actuator rod  308  by a conventional nut and bolt  334 . The bolt extends through hub  332  and through the rod  308  to non-rotatably secure the holder to the rod. Plugging head hub  332  includes an upper internally threaded opening  336  and a cylindrical lower receptacle portion  338 . 
     Permanent conduit stopper  214  includes a valve stem  339  with a square pyramidal connector  340  formed integral with the stem and positioned in holder receptacle  338 . A threaded stud  342  is formed integral with connector  340 , which is threadedly mounted in threaded opening  336 . 
     Permanent conduit stopper  214  includes a completion plug  341 , which rotatably receives valve stem  339 , as shown in FIG.  21 . The completion plug, as may be seen in FIG. 19, includes a sealing groove  344 , which has a conventional “O” ring  346  mounted therein to seal the plug to the nozzle. The completion plug also includes a locking groove  348 . Referring to FIG. 22, completion plug  341  contains a valve stem aperture  354 . A dirt seal  356  is mounted in the closure plate  350  in engagement with valve stem  339 . A pressure seal  358  is also mounted in the closure plate. 
     Valve stem  339  includes an integral thrust collar  360  in engagement with the bottom of the closure plate. A stem sealing groove  362  is formed in the valve stem below collar  360 , with a seal  364  mounted therein in engagement with the completion plug. The stem has a threaded portion  366  extending along the remainder of the length of the stem. 
     As shown in FIG. 25, a carrier has a crown  368  with a pair of arms or forks  374  and  376  attached thereto in the same manner that forks  156  and  158  are attached to crown  152 . Fork  374  includes an outer web  378  and an inner web  380 . Fork  376  includes an outer web  382  and an inner web  384 . Inner web  380  includes an internally threaded receptacle  386 , which receives a carrier fork bolt  388 . Bolt  388  is rotatably mounted in inner web  384  and threadedly mounted in the threaded receptacle  386 . Outer web  382  includes a plug aperture  390  to allow access to bolt  388 . The aperture is closed by a removable sealing plug  392 . Forks  374  and  376  terminate in generally hemispherical bottoms in the same manner as the termination of forks  156  and  158 . A deformable sealing element or paddle  394  is mounted between forks  374  and  376 . 
     Paddle  394 , as may be seen in FIG. 22, has a pair of embedded threaded retainers  396  therein. Retainers  396  are connected to conventional bolts  398 , which are mounted in crown  368 . A shim  400  is selectively positioned between the crown and the paddle to allow space between the paddle and the crown to be adjusted. A vertical recess opening  402  in the paddle contains a rigid protective tube  403  to receive valve stem  339 . 
     Referring to FIG. 25, a resilient sheet  406  is mounted on arm  374 , and a resilient sheet  408  is mounted on fork  376 . The resilient sheets  406  and  408  form a resilient seal and an effective slotted sleeve on the outer surface of forks  374  and  376 . The space between the sheets, as may be seen in FIG. 25, is occupied by a portion of paddle  394 . The paddle contains a rigid spacer collar  404 , which surrounds fork bolt  388  and maintains minimum spacing between forks  374  and  376 . 
     Referring to FIG. 22, as is conventional, the permanent stopper plug  214  is aligned inside the housing  214  so that the flat faces of the paddle  394  are perpendicular to the flow in the pipe. The plug assembly  214  is held in position by the guide yoke  318  cooperating with the tie rods  220  and  282 . After mounting of the actuator  212  and housing  210  onto the valve  208 , the actuator  212  moves plug  214  inside the tubular member  268 , through the valve  208 , and into the nozzle assembly  206 . Referring to FIG. 26, keys  370  and  372  on crown  368  of the carrier enter into engagement with the chamfer portions  244  of the respective keyways so that the keys  370  and  372  move into their respective keyways  240  and  242 , thus holding the paddle in an attitude perpendicular to the longitudinal axis of pipe  202 . 
     As shown in FIG. 21, the plug then engages the nozzle shoulder  238 , which prevents further movement of the entire plug into nozzle  216 . Referring to FIG. 23, completion plug lock screws  248  are tightened so that the nose  250  of each of the screws extends into completion plug groove  348 . In this instance, eight locking screws are utilized. However, an appropriate number of screws may be used, depending on the size of the nozzle and the pressure in the conduit. Once the lock screws  248  are in position, the holds are sealed by pipe plugs  252 . The positioning of the completion plug “O” ring  346  in the nozzle seals off the nozzle so that tapping valve  208 , along with installation housing  210  and actuator assembly  212 , may be removed. A closure plate  350  with gasket is sealingly mounted to nozzle flange  236  and is secured in position by a plurality of conventional bolts and nuts  352 . 
     As shown in FIG. 27, the permanent stopper plug is used to interrupt flow of fluid through pipe  202 . A wrenchhead  410  is mounted on the top of the valve stem extending through the plates  350  and secured to the stem with nut  411 , which engages valve stem stud  342 . The threaded portion  366  of the valve stem is threadedly engaged in the crown  368 . Rotation of the valve stem causes the crown and associated parts to move downward toward the pipe. Continued movement of the crown with the paddle causes the paddle and the associated parts to enter opening  204  in pipe  202 . As was described in detail above in connection with plug  44 , the paddle engages the bottom of the pipe, and the downward force on the paddle causes the paddle to expand and push the forks outward so that the resilient sheets engage the cut portion of the pipe, as described above. In addition, the force applied by the pressure created by the fluid in the pipe provides an additional force on the sheet, which is downstream for further sealing engagement with the cut portion of the pipe. The cooperation of the resilient sheets and the paddle is described hereinabove to effect selective control of fluid to the conduit. 
     When it is desired to allow fluid to flow through the pipe, it is only necessary to rotate the valve stem to raise the crown and associated parts to open the pipe. 
     Referring to FIG. 28, an alternate key and keyway construction is shown. A pair of opposed keys  412  are integral with key blocks  414 , which are generally rectangular in cross section. The blocks  414  are mounted in slots  417  formed into the entire depth of the exterior of the carrier crown  368 . A plurality of screws  418  engage threaded receptacles  419  in the crown to secure the blocks thereto. A pair of opposed keyway openings  420  are formed through the side wall of the nozzle  216 . The exteriors of the openings  420  are closed with a pair of elongated straps or plugs  422 , which are pressure sealed to the nozzle with continuous welds  424 . The instant construction operation in the same manner as keyway  240  and keys  370  and  372 . However, the described alternative construction allows the keyway to be as deep as the wall thickness of nozzle  216 . 
     From the foregoing, it may be seen that substantially the same parts may be utilized for a temporary plugging operation or installation of a permanent valve into a system. It is only necessary to provide a keyed plug and a modified closure plate and completion plug. The remaining parts are the same. 
     Economies of operation may be effected by utilization of the same parts. 
     Irrespective of whether the plug is used for temporary stop or as a permanent valve, the same basic construction of the sealing portion of the plug is utilized, wherein the paddle seals the lower portion of a pipe and a resilient sheet engages a substantial portion of the cut surface of the pipe to form an effective seal on the downstream side of the pipe. 
     Although specific embodiments of the herein disclosed invention have been described in detail above and shown in the accompanying drawings, it is readily apparent that those skilled in the art may make various modification and changes in the disclosed construction without departing from the spirit and scope of the invention. It is to be expressly understood that the instant invention is to be limited only by the appended claims.