Patent Publication Number: US-2023136377-A1

Title: Valve gates

Description:
BACKGROUND 
     Technical Field 
     The present disclosure relates generally to valve gates configured to be used to seal pipes or other conduits, such as against the flow of water or other liquids, and more particularly to valve gates configured to be inserted into a pipe through an opening in an outer wall thereof. 
     Description of the Related Art 
     Fluidic valves, such as pneumatic or hydraulic valves, are very old technologies that are still being improved upon today. Many new pipeline systems are built with valves pre-installed therein, to allow operator(s) to control the flow of fluids through the various conduits thereof. In some cases, existing pipeline systems are updated or retrofitted to include additional, newer valves, to provide additional control options. In many cases, retrofitting existing municipal pipelines requires dewatering the pipeline, including shutting off water to a neighborhood and disinfecting the pipeline, before installation of new components such as valves can begin. Such dewatering operations can be expensive, time-consuming, and burdensome to those living in affected areas. Thus, live pipeline valve insertion, which allows a valve to be installed within a pipeline while the pipeline is operating (that is, without dewatering the pipeline) provides significant advantages. 
     Live pipeline valve insertion typically includes mounting a tapping sleeve over an existing live pipeline within which a valve is to be installed. Once the tapping sleeve has been properly mounted to the pipeline, additional components, such as cutting and/or reaming components, may be used within the tapping sleeve to create an opening or aperture in the pipeline suitable for installation of the valve. Once the opening has been formed, a valve including a valve gate may in positioned within the tapping sleeve and in proximity to the opening so that the valve gate can be inserted into the pipeline through the opening to seal or close the pipeline, and so that the valve gate can be retracted from the pipeline through the opening to un-seal or open the pipeline. Systems for live pipeline valve insertion are commercially available, such as from ROMAC INDUSTRIES, INC. under the names QUIKVALVE and INSERTAVALVE. 
     BRIEF SUMMARY 
     A valve gate may be summarized as comprising: a rod having a central longitudinal axis, a proximal end along the central longitudinal axis, and a distal end opposite the proximal end along the central longitudinal axis; a movable body coupled to the rod such that the movable body can move distally with respect to the rod; a seal coupled to the movable body; a first lever located between the rod and a first portion of the seal and engaged with the movable body and the first portion of the seal such that distal movement of the movable body drives the first lever to rotate and push the first portion of the seal outward away from the rod in a first direction transverse to the central longitudinal axis; and a second lever located between the rod and a second portion of the seal and engaged with the movable body and the second portion of the seal such that distal movement of the movable body drives the second lever to rotate and push the second portion of the seal outward away from the rod in a second direction transverse to the central longitudinal axis. 
     The rod may be located between the first lever and the second lever. The first direction transverse to the central longitudinal axis may be opposite to the second direction transverse to the central longitudinal axis. 
     A valve gate may be summarized as comprising: a rod having a central longitudinal axis, a proximal end along the central longitudinal axis, and a distal end opposite the proximal end along the central longitudinal axis; a movable body coupled to the rod such that the movable body can move distally with respect to the rod; a seal coupled to the movable body; and a lever located between the rod and the seal and engaged with the movable body and a portion of the seal such that distal movement of the movable body drives the lever to rotate and push the portion of the seal outward away from the rod in a direction transverse to the central longitudinal axis. 
     The movable body may include a wedge and the lever may be engaged with the wedge. The movable body may include a socket and the lever may be seated within the socket. The seal may have a first end coupled to the movable body, a second end opposite the first end coupled to the movable body, and an intermediate portion between the first and second ends that wraps around a distal end of the valve gate. The rod may be threadedly engaged with the movable body such that rotation of the rod in a first direction about the central longitudinal axis drives proximal movement of the movable body and rotation of the rod in a second direction opposite the first direction about the central longitudinal axis drives distal movement of the movable body. Distal movement of the movable body may drive the lever to rotate about a fulcrum. The fulcrum may be located at a distal end of the lever. The fulcrum may be located at a proximal end of the lever. Distal movement of the movable body may drive the lever to rotate about an axis transverse or perpendicular to the central longitudinal axis. The movable body may be coupled to the rod such that the movable body can move in a direction parallel to the central longitudinal axis with respect to the rod. 
     The valve gate may further comprise: a first housing component that has an internal surface that faces toward a first side of the rod, a first side of the movable body, a first side of the seal, and a first side of the lever; and a second housing component that has an internal surface that faces toward a second side of the rod opposite the first side of the rod, a second side of the movable body opposite the first side of the movable body, a second side of the seal opposite the first side of the seal, and a second side of the lever opposite the first side of the lever. The first housing component may include a projection that extends outward from the internal surface of the first housing component, and the projection may have a curved, proximal-facing surface that provides a fulcrum for the lever such that the lever is configured to pivot on the curved surface of the projection. The first housing component may include a projection that extends outward from the internal surface of the first housing component, and the projection may have a wedge engaged with the lever. 
     At least one of the first housing component and the second housing component may have an external surface opposite the respective internal surface and a second seal coupled to the external surface such that when the valve gate is inserted into a pipeline through an opening cut into the pipeline, the second seal engages with a portion of the opening. The at least one of the first housing component and the second housing component may be exactly one of the first housing component and the second housing component. The portion of the opening may be a downstream portion of the opening. The movable body may include an undercut groove and the seal may be securely retained within the undercut groove of the movable body. 
     The valve gate may be configured to seal a first conduit having a first inner diameter and configured to seal a second conduit having a second inner diameter, wherein the first inner diameter is different than the second inner diameter. The valve gate may be configured to be inserted into the first conduit through a first opening in the first conduit, wherein the first opening has a third inner diameter smaller than the first inner diameter, and the valve gate may be configured to be inserted into the second conduit through a second opening in the second conduit, wherein the second opening has a fourth inner diameter smaller than the second inner diameter. The first inner diameter may be greater than the second inner diameter by at least one eighth or one quarter of an inch. 
     The valve gate may be located inside a tapping sleeve. The valve gate may be configured to seal a conduit having a second central longitudinal axis such that the direction transverse to the central longitudinal axis of the rod is transverse to the second central longitudinal axis of the conduit. The valve gate may be configured to seal a conduit having a second central longitudinal axis such that the direction transverse to the central longitudinal axis of the rod is aligned with the second central longitudinal axis of the conduit. The valve gate may be configured to form a seal with at least a portion of a radially-facing inner circumferential surface of a pipe. The valve gate may be configured to form a seal with at least a portion of an axially-facing end surface of a pipe. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG.  1    illustrates a perspective view of a valve gate installed within a tapping sleeve mounted to a pipeline. 
         FIG.  2    illustrates another perspective view of the valve gate installed within the tapping sleeve mounted to the pipeline illustrated in  FIG.  1   . 
         FIG.  3    illustrates a perspective view of the pipeline shown in  FIGS.  1  and  2    with other components, including the valve gate and tapping sleeve, removed. 
         FIG.  4    illustrates a perspective view of a portion of the tapping sleeve and the pipeline shown in  FIGS.  1  and  2    at a larger scale. 
         FIG.  5    illustrates a perspective view of a valve gate. 
         FIG.  6    illustrates a perspective view of the valve gate of  FIG.  5    with seal components removed. 
         FIG.  7    illustrates a perspective view of the valve gate of  FIG.  5    with seal components and a portion of a housing removed. 
         FIG.  8    illustrates a perspective view of a portion of a housing of the valve gate of  FIG.  5   . 
         FIG.  9    illustrates another perspective view of the valve gate of  FIG.  5   . 
         FIG.  10    illustrates another perspective view of the valve gate of  FIGS.  5  and  9    with seal components removed. 
         FIG.  11    illustrates another perspective view of the valve gate of  FIGS.  5  and  9    with seal components and a portion of a housing removed. 
         FIG.  12    illustrates a perspective view of a portion of a housing of the valve gate of  FIGS.  5  and  9   . 
         FIG.  13    illustrates a front view of the valve gate of  FIGS.  5  and  9    with a seal and two portions of a housing removed. 
         FIG.  14    illustrates a perspective view of a threaded rod of the valve gate of  FIGS.  5  and  9   . 
         FIG.  15    illustrates a perspective view of a threaded square nut of the valve gate of  FIGS.  5  and  9   . 
         FIG.  16    illustrates a perspective view of a pair of levers of the valve gate of  FIGS.  5  and  9   . 
         FIG.  17    illustrates a perspective view of a movable body of the valve gate of  FIGS.  5  and  9   . 
         FIG.  18    illustrates a perspective view of a seal of the valve gate of  FIGS.  5  and  9   . 
         FIG.  19    illustrates a perspective view of another valve gate. 
         FIG.  20    illustrates a perspective view of the valve gate of  FIG.  19    with seal components and a portion of a housing removed. 
         FIG.  21    illustrates a perspective view of a portion of a housing of the valve gate of  FIG.  19   . 
         FIG.  22    illustrates another perspective view of the valve gate of  FIG.  19   . 
         FIG.  23    illustrates another perspective view of the valve gate of  FIGS.  19  and  22    with seal components and a portion of a housing removed. 
         FIG.  24    illustrates a perspective view of a portion of a housing of the valve gate of  FIGS.  19  and  22   . 
         FIG.  25    illustrates a front view of the valve gate of  FIGS.  19  and  22    with a seal and two portions of a housing removed. 
         FIG.  26    illustrates a perspective view of a movable body of the valve gate of  FIGS.  19  and  22   . 
         FIG.  27    illustrates a perspective view of a seal of the valve gate of  FIGS.  19  and  22   . 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, certain specific features are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one skilled in the art will understand that the invention may be practiced with a subset of such features or with any desired combination of such features. 
       FIG.  1    illustrates a pipeline  100  and a tapping sleeve  102  mounted to and installed on the pipeline  100 .  FIG.  1    also illustrates that an uppermost portion of a valve gate  104  protrudes outward through a flange  106  at a terminal end portion of the tapping sleeve  102  distal from the pipeline  100 .  FIG.  2    illustrates another view of the pipeline  100  and tapping sleeve  102 , and shows that the tapping sleeve  102  includes a port  108  through which fluids such as liquids or gases can be provided to or removed from an interior of the tapping sleeve  102 , such that, for example, fluid pressures within the tapping sleeve  102  can be controlled (e.g., increased or decreased) by moving fluids into or out of the tapping sleeve  102  through the port  108 .  FIG.  3    illustrates the pipeline  100  by itself and shows that an aperture, hole, or opening  110  has been cut into and formed within an outer wall of the pipeline  100 .  FIG.  4    illustrates a portion of the pipeline  100  and the tapping sleeve  102  at a larger scale, showing a portion of a mechanism that securely couples the tapping sleeve  102  to the pipeline  100 . 
     As illustrated in  FIGS.  1 - 4   , the pipeline  100  has an opening  110  formed in an outer wall thereof, through which the valve gate  104  can be moved. For example, the valve gate  104  can be moved toward and into the pipeline  100  through the opening  110  to seal and close the pipeline  100  at the location of the opening  110 , and the valve gate  104  can be moved away from and out of the pipeline  100  through the opening  110  to un-seal and open the pipeline  100  at the location of the opening  110 . As illustrated in  FIG.  3   , the pipeline  100  has a hollow cylindrical shape that has a central longitudinal axis, and the opening  110  has a circular shape with its own central longitudinal axis that is perpendicular to the central longitudinal axis of the pipeline  100 . Thus, the resulting three-dimensional shape of the edge or periphery of the opening  110  forms a saddle shape defined by the geometry (including the diameter) of both the pipeline  100  and the opening  110 . 
     As illustrated in  FIG.  3   , a diameter of the opening  110  is substantially smaller than an inner diameter of the pipeline  100 . It may be advantageous to make the diameter of the opening  110  as small as feasible, and as much smaller than the inner diameter of the pipeline  100  as feasible, under the circumstances. For example, in some cases it is easier, less expensive, and less time-consuming to form a smaller opening than a larger opening in the pipeline  100 . As another example, cutting an opening into the wall of the pipeline  100  generally weakens the pipeline  100  at the location of the opening  110 , and a smaller opening  110  generally reduces the overall strength of the pipeline  100  at the location of the opening  110  by less than a larger opening would. As one further example, making the opening  110  smaller leaves more of the inner surface of the pipeline  100  intact and available for the valve gate  104  to engage with and form a seal with. In practice, however, the diameter of the opening  110  will be driven by the size of the valve gate  104  to be inserted through the opening  110 . For example, a single valve gate  104  may be configured for use with pipelines  100  of different diameters. In such cases, even though the pipelines  100  have different diameters, an opening  110  in any one of the pipelines  100  may have the same size, to accommodate the dimensions of the single valve gate  104 . 
     As also illustrated in  FIGS.  1 - 4   , the tapping sleeve  102  includes a plurality of bolts or other mechanical fasteners  112  that couple an upper portion of the tapping sleeve  102  (i.e., a portion of the tapping sleeve  102  that extends away from the pipeline  100 , which may also be referred to herein as a front portion of the tapping sleeve  102 ) to a lower portion of the tapping sleeve (i.e., a portion of the tapping sleeve  102  opposite to the upper or front portion thereof, which may also be referred to herein as a rear portion of the tapping sleeve  102 ). As illustrated in  FIG.  4   , the fasteners  112  may include bolts that can be tightened to couple the tapping sleeve  102  to the pipeline  100  and increase a pressure exerted by the tapping sleeve  102  on the outer surface of the pipeline  100 , which improves a fluid seal, such as a gaseous and/or liquid seal, between an inner surface of the tapping sleeve  102  and the outer surface of the pipeline  100 , and that can be loosened to decrease a pressure exerted by the tapping sleeve  102  on the outer surface of the pipeline  100  and to de-couple the tapping sleeve  102  from the pipeline  100 . 
       FIGS.  5 - 18    illustrate additional features of the valve gate  104 . For example,  FIGS.  5 - 8    illustrate various features of the valve gate  104  from a single consistent perspective view. In particular,  FIG.  5    illustrates all components of the valve gate  104  in an assembled state, while  FIGS.  6 - 8    each illustrate less than all components of the valve gate  104  so that additional features are revealed. As illustrated in  FIG.  5   , the valve gate  104  includes a threaded rod  114 , a threaded square nut  116 , a spacer or load transfer or movable body  118 , a first seal  120 , a first housing component or portion of a housing  122 , which may be an upstream portion of a housing  122 , a second housing component or portion of a housing  124 , which may be a downstream portion of a housing  124 , a second seal  126 , which may be an upstream seal  126 , and a third seal  128 , which may be a downstream seal  128 . 
     While some components of the valve gate  104  are referred to herein as “upstream” or “downstream” components, the valve gate  104  can, in practice, be used to seal the pipeline  100  in either direction, e.g., such that components of the valve gate referred to as “upstream” components are in fact located upstream with respect to a direction of fluid flow through the pipeline  100  or such that components of the valve gate referred to as “upstream” components are in fact located downstream with respect to a direction of fluid flow through the pipeline  100 , and such that components of the valve gate referred to as “downstream” components are in fact located upstream with respect to a direction of fluid flow through the pipeline  100 , or such that components of the valve gate referred to as “downstream” components are in fact located downstream with respect to a direction of fluid flow through the pipeline  100 . 
     When the valve gate  104  is inserted into the pipeline  100  through the opening  110 , the first seal  120  can be pushed outward from the rest of the valve gate  104 , as described further elsewhere herein, until it engages with a radially- and inwardly-facing inner surface of the pipeline  100  to engage the valve gate  104  with the pipeline  100  and create a seal between the valve gate  104  and the pipeline  100 . Thus, when the valve gate  104  is inserted into the pipeline  100  and viewed along the central longitudinal axis of the pipeline  100 , the upstream and downstream seals  126 ,  128  form front and rear portions of the valve gate  104  and the first seal  120  forms an outer peripheral portion of the valve gate  104 , and outward movement of the first seal  120  to engage with the inner surface of the pipeline  100  is generally radial movement of portions of the first seal  120 . 
     Furthermore, when the valve gate  104  is inserted into the pipeline  100  and viewed along a central longitudinal axis of the threaded rod  114 , which may be coincident with the central longitudinal axis of the opening  110  formed in the pipeline  100 , the upstream and downstream seals  126 ,  128  form outer peripheral portions of the valve gate  104  such that the valve gate  104  has a generally circular outer peripheral shape, for example with a first, upstream semi-circular portion thereof formed by the outer peripheral surface of the upstream seal  126 , and a second, downstream semi-circular portion thereof formed by the outer peripheral surface of the downstream seal  128 . This generally circular outer peripheral shape of the valve gate  104  and the upstream and downstream semi-circular portions thereof can have shapes and dimensions configured to engage with and seat snugly against the inner surface formed by the opening  110  in the pipeline  100 . 
     For example, the semi-circular outer peripheral shape of the upstream seal  126  when viewed along the central longitudinal axis of the threaded rod  114  may have a diameter or a radius of curvature that matches, corresponds to, or is the same as a diameter or a radius of curvature of the opening  110  when it is viewed along the central longitudinal axis of the threaded rod  114 , and the semi-circular outer peripheral shape of the downstream seal  128  when viewed along the central longitudinal axis of the threaded rod  114  may have a diameter or a radius of curvature that matches, corresponds to, or is the same as a diameter or a radius of curvature of the opening  110  when it is viewed along the central longitudinal axis of the threaded rod  114 . Furthermore, a length of the upstream seal  126  in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114  is at least as long as an overall height of the three-dimensional saddle shape of the opening  110  in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114 , and a length of the downstream seal  128  in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114  is at least as long as an overall height of the three-dimensional saddle shape of the opening  110  in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114 . 
     Thus, when the valve gate  104  is inserted into the pipeline  100  through the opening  110 , the upstream seal  126  can engage with and create a seal against an upstream portion of the inner surface formed by the opening  110 , and the downstream seal  128  can engage with and create a seal against a downstream portion of the inner surface formed by the opening  110 . In practice, when the valve gate  104  is inserted into the pipeline  100  to seal the pipeline, the fluid within the pipeline  100  exerts a pressure against the valve gate  104  that urges or biases the valve gate  104  in a downstream direction and toward the downstream portion of the inner surface formed by the opening  110 . Thus, a seal formed between the upstream seal  126  and the upstream portion of the inner surface formed by the opening  110  has different characteristics than a seal formed between the downstream seal  128  and the downstream portion of the inner surface formed by the opening  110 . 
     In some cases, as an example, no seal is formed at all on the upstream side of the valve gate  104 , as the fluid pressure makes forming such a seal more difficult or complicated but assists in forming a seal on the downstream side of the valve gate  104 . Thus, in some implementations, the upstream seal  126  has different properties, such as different dimensions or different material properties, than the downstream seal  128 . In some implementations, the upstream seal  126  is larger than and/or made of different material(s) than the downstream seal  128 . In some implementations, the upstream seal  126  may be omitted from the valve gate  104  entirely such that no seal is formed during operation between the valve gate  104  and the upstream portion of the inner surface formed by the opening  110 . 
       FIG.  6    illustrates the valve gate  104  with the upstream and downstream seals  126 ,  128  removed such that additional features of the upstream portion of the housing  122 , such as a contour of an outer surface thereof, are shown.  FIG.  7    illustrates the valve gate  104  with the upstream and downstream seals  126 ,  128 , and the upstream portion of the housing  122  removed such that additional features of the valve gate  104 , such as of the threaded rod  114 , the nut  116 , the movable body  118 , the first seal  120 , and a pair of levers  130  thereof are shown.  FIG.  8    illustrates the downstream portion of the housing  124  by itself and shows that the downstream portion of the housing  124  includes a protrusion  132  that extends inwardly and in an upstream direction from an inner or upstream surface of the downstream portion of the housing  124 . 
     As illustrated in  FIG.  8   , when the valve gate  104  is located within the pipeline  100  and the downstream portion of the housing  124  and the protrusion  132  are viewed along the central longitudinal axis of the pipeline  100 , the protrusion  132  includes a pair of sockets  134   a ,  134   b , each of which includes a curved bearing surface. In particular, when viewed along the central longitudinal axis of the pipeline  100 , the first socket  134   a  is spaced apart from the central longitudinal axis of the threaded rod  114  by a first distance in a first direction, and the second socket  134   b  is spaced apart from the central longitudinal axis of the threaded rod  114  by a second distance, which may be the same as the first distance, in a second direction, which may be opposite to the first direction. Each of the sockets  134   a ,  134   b  includes a bearing surface that extends linearly in a direction along a respective axis aligned with or parallel to the central longitudinal axis of the pipeline  100 , and that is curved about such respective axes. Thus, each of the sockets  134   a ,  134   b  forms a respective channel or cup oriented to face upward toward the nut  116  when the valve gate  104  is assembled. Each of the sockets  134   a ,  134   b  can form a respective fulcrum for a respective one of the levers  130  when the valve gate  104  is assembled and in use, as described further elsewhere herein. In some embodiments, the levers  130  may be mounted in the sockets  134   a ,  134   b  on axles. 
       FIGS.  9 - 12    illustrate various features of the valve gate  104  from a single consistent perspective, which is different than the perspective used in  FIGS.  5 - 8   . In particular,  FIG.  9    illustrates all components of the valve gate  104  in an assembled state, while  FIGS.  10 - 12    each illustrate less than all components of the valve gate  104  so that additional features are revealed. 
       FIG.  10    illustrates the valve gate  104  with the upstream and downstream seals  126 ,  128  removed such that additional features of the downstream portion of the housing  124 , such as a contour of an outer surface thereof, are shown.  FIG.  11    illustrates the valve gate  104  with the upstream and downstream seals  126 ,  128 , and the downstream portion of the housing  124  removed such that additional features of the valve gate  104 , such as of the threaded rod  114 , the nut  116 , the movable body  118 , the first seal  120 , and the pair of levers  130  are shown.  FIG.  12    illustrates the upstream portion of the housing  122  by itself and shows that the upstream portion of the housing  122  includes a protrusion  136  that extends inwardly and in a downstream direction from an inner or downstream surface of the upstream portion of the housing  122 . 
     As illustrated in  FIG.  12   , when the valve gate  104  is located within the pipeline  100  and the upstream portion of the housing  122  and the protrusion  136  are viewed along the central longitudinal axis of the pipeline  100 , the protrusion  136  includes a pair of sockets  138   a ,  138   b , each of which includes a curved bearing surface. In particular, when viewed along the central longitudinal axis of the pipeline  100 , the first socket  138   a  is spaced apart from the central longitudinal axis of the threaded rod  114  by a first distance in a first direction (which may be the same as the first distance and first direction, respectively, described with respect to the protrusion  132 ), and the second socket  138   b  is spaced apart from the central longitudinal axis of the threaded rod  114  by a second distance, which may be the same as the first distance, in a second direction, which may be opposite to the first direction (and which may be the same as the second distance and second direction, respectively, described with respect to the protrusion  132 ). Each of the sockets  138   a ,  138   b  includes a bearing surface that extends linearly in a direction along a respective axis aligned with or parallel to the central longitudinal axis of the pipeline  100 , and that is curved about such respective axes. Thus, each of the sockets  138   a ,  138   b  forms a respective channel or cup oriented to face upward toward the nut  116  when the valve gate  104  is assembled. Each of the sockets  138   a ,  138   b  can form a respective fulcrum for a respective one of the levers  130  when the valve gate  104  is assembled and in use, as described further elsewhere herein. In some embodiments, the levers  130  may be mounted in the sockets  138   a ,  138   b  on axles. 
       FIG.  13    illustrates a front view of the valve gate  104  with the upstream portion of the housing  122 , the downstream portion of the housing  124 , the upstream seal  126 , and the downstream seal  128  removed such that other features of the valve gate  104 , such as of the threaded rod  114 , the nut  116 , the movable body  118 , the first seal  120 , and the pair of levers  130  are shown.  FIG.  14    illustrates the threaded rod  114  by itself such that additional features thereof are revealed. As illustrated in  FIG.  14   , the threaded rod  114  includes a cylindrical and threaded main body  140  that extends along the central longitudinal axis of the threaded rod  114 , a flange  142  that extends radially outward from the central longitudinal axis of the threaded rod  114 , and a terminal end portion  144  that includes a groove or keyway  146  that is cut radially inward into the terminal end portion  144  and extends longitudinally along the length of the terminal end portion  144  in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114 . 
     As illustrated in  FIG.  1   , the threaded rod  114  can be positioned within the tapping sleeve  102  such that the flange  142  is inside the tapping sleeve  102 . In various embodiments, the flange  142  is retained such that it cannot travel along the central longitudinal axis of the threaded rod  114 , but such that it can rotate about the central longitudinal axis of the threaded rod  114 , and therefore such that the entire threaded rod  114  cannot travel along its own central longitudinal axis but can rotate about its own central longitudinal axis. As further illustrated in  FIG.  1   , the threaded rod  114  can be positioned within the tapping sleeve  102  such that its terminal end portion  144  and the keyway  146  thereof extend outside of the tapping sleeve  102 . Thus, by engaging other device(s) with the terminal end portion  144  of the threaded rod  114 , including with the keyway  146  thereof, an operator can actuate the threaded rod  114 , such as to rotate about its own central longitudinal axis. While the threaded rod  114  described and illustrated herein includes the keyway  146  for engaging other devices with the terminal end portion  144  of the threaded rod  114 , in other implementations, the threaded rod  114  may include other features, such as a spline or a square taper, for engaging other devices with the terminal end portion  144  of the threaded rod  114 . 
       FIG.  15    illustrates the threaded square nut  116  by itself such that additional features thereof are revealed. The threaded square nut can have an internal bore that is threaded with threads complementary to and configured to engage with the threads of the threaded rod  114 , and an outer surface that is generally square when the valve gate  104  is assembled and viewed along the central longitudinal axis of the threaded rod  114 . In use, the nut  116  can be threaded onto the threads of the main body of the threaded rod  114  and positioned within the tapping sleeve  102  with the square outer surface thereof retained such that it can travel along the central longitudinal axis of the threaded rod  114 , but such that it cannot rotate about the central longitudinal axis of the threaded rod  114 . Thus, when the threaded rod  114  is actuated to rotate about its own central longitudinal axis, the engagement of the threads between the threaded rod  114  and the nut  116  and the retention of the nut  116  against rotation about the central longitudinal axis of the threaded rod  114  result in travel of the nut  116  along the central longitudinal axis of the threaded rod  114 , with rotation of the rod  114  in a first direction causing travel of the nut  116  in a first direction and rotation of the rod  114  in a second direction opposite the first resulting in travel of the nut  116  in a second direction opposite the first. 
       FIG.  16    illustrates the pair of levers  130  by themselves such that additional features thereof are revealed. As illustrated in  FIG.  16   , the two levers  130 , which are identical to one another and positioned to form mirror images of one another, each include a shaft having a groove  148  extending into and along a first side thereof and a protrusion or ridge  150  extending out of a second side thereof opposite to the first side thereof. Furthermore, each of the levers  130  has a first curved surface at a first end of its shaft that curves from the first side thereof including the groove  148  to the second side thereof including the protrusion or ridge  150 . As further illustrated in  FIG.  16   , when the valve gate  104  is assembled, the pair of levers  130  are arranged such that they are generally aligned with one another, such that the first sides thereof and the grooves formed therein face toward one another, and such that the second sides thereof and the protrusions formed therein face away from one another. Respective end portions of the levers  130  can be spaced apart from one another by a distance corresponding to or matching a distance between the sockets  134   a  and  134   b  and a distance between the sockets  138   a  and  138   b , such that the end portions of the levers  130  can be seated within the sockets  134   a ,  134   b ,  138   a , and  138   b  when the valve gate  104  is assembled. Furthermore, the grooves  148  formed in the inner surfaces of the levers  130  can have curvatures configured to accommodate, corresponding to, or matching, the curvature or diameter of the threaded rod  114 , such that when the valve gate  104  is assembled, the threaded rod  114  can extend between the levers  130  and be positioned at least partially within the grooves  148  such that the levers  130  fit at least partially around the curvature of the threaded rod  114 . 
       FIG.  17    illustrates the movable body  118  by itself such that additional features thereof are revealed. As illustrated in  FIG.  17   , the movable body  118  includes a hollow cylindrical body or spacer  152  that has a central longitudinal axis coincident with the central longitudinal axis of the threaded rod  114 , and that is configured to extend around the threaded rod  114  such that the threaded rod  114  can extend through the spacer  152  without contacting the spacer  152 . The movable body  118  also includes a first leg  154   a  that extends longitudinally away from a terminal end portion of the spacer  152  at a first side of the spacer  152  in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114 , and a second leg  154   b  that extends longitudinally away from the terminal end portion of the spacer  152  at a second side of the spacer  152  opposite to the first side thereof in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114 . As illustrated in  FIG.  17   , the first leg  154   a  and the second leg  154   b  each include a groove extending into and along a length of an inner side surface thereof, such that the grooves of the first and second legs  154   a ,  154   b  face each other. These grooves can have curvatures configured to accommodate, corresponding to, or matching, the curvature or diameter of the threaded rod  114 , such that when the valve gate  104  is assembled, the threaded rod  114  can extend between the first and second legs  154   a ,  154   b , and be positioned at least partially within the grooves such that the legs  154   a ,  154   b  fit at least partially around the curvature of the threaded rod  114 . 
     As illustrated in  FIG.  17   , the first and second legs  154   a ,  154   b  each have square or rectangular cross-sectional shapes when viewed along the central longitudinal axis of the threaded rod  114 . As further illustrated in  FIG.  17   , a terminal end portion of the first leg  154   a  distal from the spacer  152  includes a wedge  156   a , such that the cross-sectional shape of the first leg  154   a  decreases along the length of the wedge  156   a  to a tip or terminal distal end of the first leg  154   a . In particular, the inner side surface of the first leg  154   a  that includes the groove described above extends linearly longitudinally away from the terminal end portion of the spacer  152  to the terminal distal end of the first leg  154   a  and an outer side surface of the first leg  154   a  opposite to the inner side surface thereof and to the groove formed therein extends linearly longitudinally away from the terminal end portion of the spacer  152  to the wedge  156   a , and then both away from the terminal end portion of the spacer  152  and toward the inner side surface throughout the length of the wedge  156   a  until the outer side surface meets the inner side surface at the terminal distal end of the first leg  154   a . Thus, the wedge  156   a  has a variable rectangular cross-sectional shape that tapers toward an edge at the terminal distal end of the first leg  154   a , where the edge extends generally front-to-back when the valve gate  104  is assembled and viewed along the central longitudinal axis of the pipeline  100 . 
     Similarly, a terminal end portion of the second leg  154   b  distal from the spacer  152  includes a wedge  156   b , such that the cross-sectional shape of the second leg  154   b  decreases along the length of the wedge  156   b  to a tip or terminal distal end of the second leg  154   b . In particular, the inner side surface of the second leg  154   b  that includes the groove described above extends linearly longitudinally away from the terminal end portion of the spacer  152  to the terminal distal end of the second leg  154   b  and an outer side surface of the second leg  154   b  opposite to the inner side surface thereof and to the groove formed therein extends linearly longitudinally away from the terminal end portion of the spacer  152  to the wedge  156   b , and then both away from the terminal end portion of the spacer  152  and toward the inner side surface throughout the length of the wedge  156   b  until the outer side surface meets the inner side surface at the terminal distal end of the second leg  154   b . Thus, the wedge  156   b  has a variable rectangular cross-sectional shape that tapers toward an edge at the terminal distal end of the second leg  154   b , where the edge extends generally front-to-back when the valve gate  104  is assembled and viewed along the central longitudinal axis of the pipeline  100 . Thus, when taken together with the rest of the movable body  118 , the wedges  156   a  and  156   b  form a terminal end portion of the movable body  118  and taper toward one another at the terminal end portion of the movable body  118 . 
     The movable body  118  also includes a first arm  158   a  that extends radially outward away from the first side of the spacer  152 , from which the first leg  154   a  extends, in a direction transverse or perpendicular to the central longitudinal axis of the threaded rod  114  and transverse or perpendicular to the first leg  154   a , and a second arm  158   b  that extends radially outward away from the second side of the spacer  152 , from which the second leg  154   b  extends, in a direction transverse or perpendicular to the central longitudinal axis of the threaded rod  114  and transverse or perpendicular to the second leg  154   b . As illustrated in  FIG.  17   , the first and second arms  158   a ,  158   b  each have square or rectangular cross-sectional shapes when viewed along their own respective central longitudinal axes, which may be radial, transverse, and/or perpendicular to the central longitudinal axis of the threaded rod  114 . 
     As further illustrated in  FIG.  17   , the first arm  158   a  includes an undercut groove  160   a  formed in a side surface of the first arm  158   a  that faces toward the wedge  156   a  at the terminal end portion of the first leg  154   a , and that extends front-to-back along a length of the first arm  158   a  when the valve gate  104  is assembled and viewed along the central longitudinal axis of the pipeline  100 . Similarly, the second arm  158   b  includes an undercut groove  160   b  formed in a side surface of the second arm  158   b  that faces toward the wedge  156   b  at the terminal end portion of the second leg  154   b , and that extends front-to-back along a length of the second arm  158   b  when the valve gate  104  is assembled and viewed along the central longitudinal axis of the pipeline  100 . When the valve gate  104  is assembled, portions of the first seal  120  can be seated within the first and second undercut grooves  160   a ,  160   b  to couple the first seal  120  to the movable body  118 , as described further elsewhere herein. 
       FIG.  18    illustrates the first seal  120  by itself such that additional features thereof are revealed. As illustrated in  FIG.  18   , the first seal  120  is generally U-shaped, and includes a first end portion  162   a , which forms a first terminal end of its overall U-shape, and a second end portion  162   b , which forms a second terminal end of its overall U-shape. The first seal  120  also includes an intermediate portion or main body  164  that extends longitudinally away from the first end portion  162   a , curves to form a semi-circular curved intermediate or central portion thereof, and then extends longitudinally toward the second end portion  162   b . When the valve gate  104  is assembled, the longitudinally extending portions of the main body  164  may be aligned with or extend parallel or substantially parallel to each other and to the central longitudinal axis of the threaded rod  114 . 
     As also illustrated in  FIG.  18   , the first seal  120  has a generally rectangular cross-sectional profile along a length of its overall U-shape, and the dimensions of the cross-sectional profile of the first seal  120  are variable along its length. For example, dimensions of the cross-sectional profile of the main body  164  of the first seal  120  decrease or taper toward each of the first end portion  162   a  and the second end portion  162   b  of the first seal  120 , partially forming respective neck portions thereof. As another example, the first seal  120  includes a first indentation  166   a  formed in an inner surface of a first longitudinally-extending portion thereof (i.e., a surface that faces inward with respect to the overall U-shape or toward a second longitudinally-extending portion thereof) and a second indentation  166   b  formed in an inner surface of the second longitudinally-extending portion thereof (i.e., a surface that faces inward with respect to the overall U-shape or toward the first longitudinally-extending portion thereof). Dimensions of the cross-sectional profile of the main body  164  of the first seal  120  decrease or taper at each of the first and second indentations  166   a ,  166   b , such as by amounts corresponding to dimensions of the protrusions or ridges  150  of the levers  130 , such that the ridges  150  of the levers  130  can be snugly seated within the indentations  166   a ,  166   b  when the valve gate  104  is assembled. 
     As further illustrated in  FIG.  18   , the first end portion  162   a  includes a neck  168   a  coupled to the adjacent tapered portion of the main body  164  and a head, or a rail or shaft  170   a  that extends front-to-back when the valve gate  104  is assembled and viewed along the central longitudinal axis of the pipeline  100 . Thus, the neck  168   a  couples the shaft  170   a  to the tapered portion of the main body  164 . Similarly, the second end portion  162   b  includes a neck  168   b  coupled to the adjacent tapered portion of the main body  164  and a head, or a rail or shaft  170   b  that extends front-to-back when the valve gate  104  is assembled and viewed along the central longitudinal axis of the pipeline  100 . Thus, the neck  168   b  couples the shaft  170   b  to the tapered portion of the main body  164 . The shafts  170   a ,  170   b  have dimensions corresponding to or matching dimensions of the undercut grooves  160   a ,  160   b , such that the shafts  170   a ,  170   b  can be seated within the undercut grooves  160   a ,  160   b  to securely couple the first seal  120  to the movable body  118 . 
       FIGS.  7 ,  11 , and  13    illustrate additional details regarding the ways in which the various components of the valve gate  104  engage and interact with one another. As illustrated in  FIGS.  7 ,  11 , and  13   , when the valve gate  104  is assembled, the nut  116  is threaded onto the threaded rod  114  and positioned proximate the flange  142  of the threaded rod  114 . The movable body  118  is mounted on the threaded rod  114  such that the threaded rod  114  extends through the spacer  152  and between the first and second legs  154   a ,  154   b  such that the threaded rod  114  is positioned at least partially within the grooves formed in the inner surfaces of the first and second legs  154   a ,  154   b , such that the nut  116  is located between the movable body  118  and the flange  142  of the threaded rod  114  and abuts directly against a terminal end portion of the movable body  118  opposite to the wedges  156   a ,  156   b  thereof, and such that the movable body  118  can move freely along the length of the threaded rod  114  and the central longitudinal axis thereof. 
     As further illustrated in  FIGS.  7 ,  11 , and  13   , when the valve gate  104  is assembled, the shafts  170   a ,  170   b  of the first and second end portions  162   a ,  162   b  of the first seal  120  are seated within the undercut grooves  160   a ,  160   b  of the first and second arms  158   a ,  158   b  such that the first end portion  162   a  of the first seal  120  is securely coupled to the first arm  158   a , the second end portion  162   b  of the first seal  120  is securely coupled to the second arm  158   b , and the main body  164  of the first seal  120  extends around a terminal distal end portion of the threaded rod  114  and wraps around a distal end of the valve gate  104 . 
     As further illustrated in  FIGS.  7 ,  11 , and  13   , the upstream portion of the housing  122  and the downstream portion of the housing  124  are positioned such that a majority of the threaded rod  114 , a majority of the movable body  118 , an inner portion of the first seal  120 , and the pair of levers  130  are located or sandwiched between the upstream portion of the housing  122  and the downstream portion of the housing  124 . When the upstream portion of the housing  122  and the downstream portion of the housing  124  are positioned in this manner, the protrusions  132  and  136  are positioned adjacent to and/or spaced apart from one another within an open space or pocket formed between the terminal distal end of the threaded rod  114  and an inner surface of the main body  164  at a central portion of the main body  164 . The upstream portion of the housing  122  and the downstream portion of the housing  124  are coupled to one another in this configuration but not rigidly coupled to at least some of the other components of the valve gate  104  described herein, such that, for example, the threaded rod  114  can rotate freely, the nut  116  can translate freely, the movable body  118  can translate freely, the seal  120  can move freely, and the levers  130  can rotate freely, with respect to the upstream portion of the housing  122  and the downstream portion of the housing  124 . 
     As further illustrated in  FIGS.  7 ,  11 , and  13   , when the valve gate  104  is assembled, the levers  130  are positioned as described elsewhere herein, that is, generally aligned with one another such that the grooves  148  face toward one another and such that the threaded rod  114  extends between the levers  130  and is positioned at least partially within the grooves  148 . When so assembled, the levers are each located between the threaded rod  114  and a respective portion of the first seal  120 , as well as between the wedges  156   a ,  156   b  of the movable body and the protrusions  132 ,  136  of the upstream portion of the housing  122  and the downstream portion of the housing  124 . Furthermore, when so assembled, a first curved end of a first one of the levers  130  is positioned within both the first socket  134   a  formed in the protrusion  132  of the downstream portion of the housing  124  and the second socket  138   b  formed in the protrusion  136  of the upstream portion of the housing  122 . Thus, the first one of the levers  130  can rotate, such as either frictionally or without friction by rolling against the curved surfaces of the first socket  134   a  and the second socket  138   b , about an axis aligned with a central longitudinal axis of the pipeline  100  with respect to the other components of the assembled valve gate  104 . 
     Furthermore, when the valve gate  104  is assembled, a second curved end of the first one of the levers  130  opposite to the first curved end thereof and the sockets  134   a  and  138   b  is engaged with and abuts against the outer side surface of the wedge  156   a  such that the wedge  156   a  extends between the second curved end of the first one of the levers  130  and the threaded rod  114 . Additionally, the first one of the levers  130  is positioned such that an outer surface thereof is directly engaged with and abuts against an inner side surface of the main body  164  of the first seal  120 , for example, such that the protrusion  150  of the first one of the levers  130  is seated snugly within the first indentation  166   a  of the main body  164  of the first seal  120 . 
     Similarly, when so assembled, a first curved end of a second one of the levers  130  is positioned within both the second socket  134   b  formed in the protrusion  132  of the downstream portion of the housing  124  and the first socket  138   a  formed in the protrusion  136  of the upstream portion of the housing  122 . Thus, the second one of the levers  130  can rotate, such as either frictionally or without friction by rolling against the curved surfaces of the second socket  134   b  and the first socket  138   a , about an axis aligned with a central longitudinal axis of the pipeline  100  with respect to the other components of the assembled valve gate  104 . 
     Furthermore, when the valve gate  104  is assembled, a second curved end of the second one of the levers  130  opposite to the first curved end thereof and the sockets  134   b  and  138   a  is engaged with and abuts against the outer side surface of the wedge  156   b  such that the wedge  156   b  extends between the second curved end of the second one of the levers  130  and the threaded rod  114 . Additionally, the second one of the levers  130  is positioned such that an outer surface thereof is directly engaged with and abuts against an inner side surface of the main body  164  of the first seal, for example, such that the protrusion  150  of the second one of the levers  130  is seated snugly within the second indentation  166   b  of the main body  164  of the first seal  120 . 
     To actuate and operate the valve gate  104 , such as to move the valve gate  104  into the pipeline  100  through the opening  110  and thereby begin to seal the pipeline  100 , as described elsewhere herein, an operator can actuate the threaded rod  114  to rotate about its own central longitudinal axis by engaging other device(s) with the terminal end portion  144  of the threaded rod  114 , including with the keyway  146  thereof. Actuating the threaded rod  114  to rotate about its own central longitudinal axis, as also described elsewhere herein, causes the nut  116  to travel along the length of the threaded rod  114  and its central longitudinal axis. Because the nut  116  abuts against a terminal end portion of the movable body  118  and the movable body  118  is free to move along the length of the threaded rod  114 , causing the nut  116  to travel along the length of the threaded rod  114  also causes the movable body  118  to travel along the length of the threaded rod  114  and its central longitudinal axis. 
     While the valve gate  104  is being moved into the pipeline  100  through the opening  110 , and before a distal end of the valve gate  104  comes into contact with a surface of the pipeline  100  opposite to the opening  110 , causing movement of the movable body  118  along the length of the threaded rod  114  also causes the rest of the valve gate  104 , including the first seal  120 , the levers  130 , the upstream portion of the housing  122 , and the downstream portion of the housing  124 , to move along the length of the threaded rod  114  into the pipeline  100 . Once the valve gate  104  has been moved into the pipeline  100  through the opening  110  and the distal end of the valve gate  104  comes into contact with the surface of the pipeline  100  opposite the opening  110 , however, further distal movement of a central portion of the main body  164  of the first seal  120  (i.e., a distal portion thereof), the upstream portion of the housing  122 , and the downstream portion of the housing  124  is blocked or prevented by the engagement of the valve gate  104  with the surface of the pipeline  100  opposite the opening  110 . 
     Thus, at this stage, continued movement of the movable body  118  along the length of the threaded rod  114  causes continued movement of the first and second end portions  162   a ,  162   b  of the first seal, but not of the entirety of the main body  164  of the first seal  120 . Continued movement of the movable body  118  along the length of the threaded rod  114  also causes the outer surfaces of the wedges  156   a ,  156   b  to exert forces against the second curved ends of the levers  130 , which, when combined with the engagement of the first curved ends of the levers  130  with the sockets  134   a ,  134   b ,  138   a , and  138   b , causes the levers  130  to pivot or rotate outward with respect to one another and with respect to the threaded rod  114  about their first curved ends engaged with the sockets  134   a ,  134   b ,  138   a , and  138   b . Such rotation may be without friction, in the sense that the curved surfaces of the levers  130  roll along, rather than slide along or rotate against, the curved surfaces of the sockets  134   a ,  134   b ,  138   a , and  138   b.    
     Such outward rotation of the levers  130 , combined with the engagement of the outer surfaces of the levers  130  with the inner surface of the first seal  120 , causes the portions of the first seal  120  engaged with the levers  130  to move outward, thereby causing the overall profile of the valve gate  104  when viewed along the central longitudinal axis of the pipeline  100  to expand, such as to a profile that is larger than the opening  110  in the pipeline  100 . In particular, because the outer surfaces of the wedges  156   a ,  156   b  exert forces against the levers  130  at locations farther from the sockets  134   a ,  134   b ,  138   a , and  138   b  than the locations at which the levers  130  engage with the inner surface of the first seal  120 , the forces applied by the levers  130  to the first seal  120  are larger than the forces applied by the wedges  156   a ,  156   b  to the levers  130  and the travel of the portions of the first seal  120  engaged with the levers  130  is smaller than the travel of the ends of the levers  130  engaged with the wedges  156   a ,  156   b . In some embodiments, the continued movement of the first and second end portions  162   a ,  162   b  of the first seal, but not of the entirety of the main body  164  of the first seal  120  allows for some slack to develop in the seal  120  between the first and second end portions  162   a ,  162   b  and the distal, central portion of the main body  164 , which slack can be taken up, such as entirely taken up, by the expansion of the main body  164  outwards with respect to the threaded rod  114 . 
     While the first seal  120  is expanding radially outward with respect to the central longitudinal axis of the pipeline  100 , and before the first seal  120  fully engages with the inner surface of the pipeline  100  to form a complete seal therewith, continued movement of the movable body  118  along the length of the threaded rod  114  causes continued outward rotation of the levers  130  and continued expansion of the main body  164  of the first seal  120  radially outwards with respect to the central longitudinal axis of the pipeline  100 . Once the main body  164  of the first seal  120  fully engages with the inner surface of the pipeline  100  and forms a complete seal therewith, however, further expansion of the first seal  120  is blocked or prevented by the engagement of the first seal  120  with the inner surface of the pipeline  100 . At this stage, rotation of the threaded rod  114  can be ceased and the actuation of the valve gate  104  to seal the pipeline  100  is complete. In this configuration, the valve gate  104  is in an engaged, inserted, closed, and sealed position or configuration. 
     To actuate and operate the valve gate  104 , such as to retract the valve gate  104  by moving the valve gate  104  out of the pipeline  100  through the opening  110 , as described elsewhere herein, an operator can actuate the threaded rod  114  to rotate about its own central longitudinal axis by engaging other device(s) with the terminal end portion  144  of the threaded rod  114 , including with the keyway  146  thereof, such that the threaded rod  114  rotates in a direction opposite to that used to insert the valve gate  104 . Such rotation of the threaded rod  114  acts to move the components of the valve gate  104  in directions opposite to those described above for the insertion of the valve gate  104 . For example, in a first step, the first seal  120  is retracted into the rest of the valve gate  104  and the overall profile of the valve gate  104  as viewed along the central longitudinal axis of the pipeline  100  decreases, such as to a profile that is smaller than the opening  110  in the pipeline  100 . As another example, in a second step, the valve gate  104  may be retracted from the pipeline  100  through the opening  110  therein. Such actions can be used to move the valve gate  104  to a disengaged, retracted, withdrawn, open, and unsealed position or configuration. Inserting and retracting the valve gate  104  to seal and unseal the pipeline  100  can be repeated as desired. 
       FIGS.  19 - 27    illustrate additional features of alternative valve gate components that can be used with any of the components and features of the valve gate  104  described herein.  FIGS.  19 - 27    illustrate such alternative valve gate components together with the threaded rod  114 , the nut  116 , and the pair of levers  130 , which are oriented upside down in  FIGS.  19 - 27    with respect to the other components of the valve gate as compared to their orientation with respect to the other components of the valve gate  104  in  FIGS.  5 - 18   . For example,  FIGS.  19 - 21    illustrate various features of alternative valve gate components from a single consistent perspective view. For example,  FIG.  19    illustrates the alternative components in an assembled state. As illustrated in  FIG.  19   , the alternative components include a spacer or load transfer or movable body  218 , a seal  220 , a first housing component or portion of a housing  222 , which may be an upstream portion of a housing  222 , and a second housing component or portion of a housing  224 , which may be a downstream portion of a housing  224 . 
       FIG.  20    illustrates the alternative components with the upstream portion of the housing  222  removed such that additional features of the alternative components, such as of the movable body  218  and the seal  220  are shown.  FIG.  21    illustrates the downstream portion of the housing  224  by itself and shows that the downstream portion of the housing  224  includes a protrusion  232  that extends inwardly and in an upstream direction from an inner or upstream surface of the downstream portion of the housing  224 . 
     As illustrated in  FIG.  21   , when a valve gate is located within the pipeline  100  and the downstream portion of the housing  224  and the protrusion  232  are viewed along the central longitudinal axis of the pipeline  100 , the protrusion  232  includes a first wedge  256   a , such that the cross-sectional shape of the first wedge  256   a  decreases along the length of the wedge  256   a  to a tip or terminal end of the first wedge  256   a . In particular, an inner side surface of the first wedge  256   a  extends generally parallel to the central longitudinal axis of the threaded rod  114  and an outer side surface of the first wedge  256   a  opposite to the inner side surface thereof extends at an oblique angle toward the inner side surface throughout the length of the wedge  256   a  until the outer side surface meets the inner side surface at the terminal end of the first wedge  256   a . Thus, the wedge  256   a  has a variable rectangular cross-sectional shape that tapers toward the nut  116  and toward an edge at the terminal end of the first wedge  256   a , where the edge extends generally front-to-back when the valve gate is assembled and viewed along the central longitudinal axis of the pipeline  100 . 
     As further illustrated in  FIG.  21   , when a valve gate is located within the pipeline  100  and the downstream portion of the housing  224  and the protrusion  232  are viewed along the central longitudinal axis of the pipeline  100 , the protrusion  232  also includes a second wedge  256   b , such that the cross-sectional shape of the second wedge  256   b  decreases along the length of the wedge  256   b  to a tip or terminal end of the second wedge  256   b . In particular, an inner side surface of the second wedge  256   b  extends generally parallel to the central longitudinal axis of the threaded rod  114  and an outer side surface of the second wedge  256   b  opposite to the inner side surface thereof extends at an oblique angle toward the inner side surface throughout the length of the wedge  256   b  until the outer side surface meets the inner side surface at the terminal end of the second wedge  256   b . Thus, the wedge  256   b  has a variable rectangular cross-sectional shape that tapers toward the nut  116  and toward an edge at the terminal end of the second wedge  256   b , where the edge extends generally front-to-back when the valve gate is assembled and viewed along the central longitudinal axis of the pipeline  100 . Thus, when taken together with the rest of the downstream portion of the housing  224 , the wedges  256   a  and  256   b  taper toward one another. 
       FIGS.  22 - 24    illustrate various features of the alternative components from a single consistent perspective, which is different than the perspective used in  FIGS.  19 - 21   . In particular,  FIG.  22    illustrates the alternative components in an assembled state.  FIG.  23    illustrates the alternative components with the downstream portion of the housing  224  removed such that additional features of the alternative components, such as of the movable body  218  and the seal  220  are shown.  FIG.  24    illustrates the upstream portion of the housing  222  by itself and shows that the upstream portion of the housing  222  includes a protrusion  236  that extends inwardly and in a downstream direction from an inner or downstream surface of the upstream portion of the housing  222 . 
     As illustrated in  FIG.  24   , when a valve gate is located within the pipeline  100  and the upstream portion of the housing  222  and the protrusion  236  are viewed along the central longitudinal axis of the pipeline  100 , the protrusion  236  includes a third wedge  256   c , such that the cross-sectional shape of the third wedge  256   c  decreases along the length of the wedge  256   c  to a tip or terminal end of the third wedge  256   c . In particular, an inner side surface of the third wedge  256   c  extends generally parallel to the central longitudinal axis of the threaded rod  114  and an outer side surface of the third wedge  256   c  opposite to the inner side surface thereof extends at an oblique angle toward the inner side surface throughout the length of the wedge  256   c  until the outer side surface meets the inner side surface at the terminal end of the third wedge  256   c . Thus, the wedge  256   c  has a variable rectangular cross-sectional shape that tapers toward the nut  116  and toward an edge at the terminal end of the third wedge  256   c , where the edge extends generally front-to-back when the valve gate is assembled and viewed along the central longitudinal axis of the pipeline  100 . 
     As further illustrated in  FIG.  24   , when a valve gate is located within the pipeline  100  and the upstream portion of the housing  222  and the protrusion  236  are viewed along the central longitudinal axis of the pipeline  100 , the protrusion  236  also includes a fourth wedge  256   d , such that the cross-sectional shape of the fourth wedge  256   d  decreases along the length of the wedge  256   d  to a tip or terminal end of the fourth wedge  256   d . In particular, an inner side surface of the fourth wedge  256   d  extends generally parallel to the central longitudinal axis of the threaded rod  114  and an outer side surface of the fourth wedge  256   d  opposite to the inner side surface thereof extends at an oblique angle toward the inner side surface throughout the length of the wedge  256   d  until the outer side surface meets the inner side surface at the terminal end of the fourth wedge  256   d . Thus, the wedge  256   d  has a variable rectangular cross-sectional shape that tapers toward the nut  116  and toward an edge at the terminal end of the fourth wedge  256   d , where the edge extends generally front-to-back when the valve gate is assembled and viewed along the central longitudinal axis of the pipeline  100 . Thus, when taken together with the rest of the upstream portion of the housing  222 , the wedges  256   c  and  256   d  taper toward one another. 
       FIG.  25    illustrates a front view of a valve gate with the upstream portion of the housing  222  and the downstream portion of the housing  224  removed such that other features of the valve gate, such as of the threaded rod  114 , the nut  116 , the movable body  218 , the seal  220 , and the pair of levers  130  are shown. 
       FIG.  26    illustrates the movable body  218  by itself such that additional features thereof are revealed. As illustrated in  FIG.  26   , the movable body  218  includes a hollow cylindrical body or spacer  252  that has a central longitudinal axis coincident with the central longitudinal axis of the threaded rod  114 , and that is configured to extend around the threaded rod  114  such that the threaded rod  114  can extend through the spacer  252  without contacting the spacer  252 . The movable body  218  also includes a first leg  254   a  that extends longitudinally away from a terminal end portion of the spacer  252  at a first side of the spacer  252  in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114 , and a second leg  254   b  that extends longitudinally away from the terminal end portion of the spacer  252  at a second side of the spacer  252  opposite to the first side thereof in a direction aligned with or parallel to the central longitudinal axis of the threaded rod  114 . As illustrated in  FIG.  26   , the first leg  254   a  and the second leg  254   b  each include a groove extending into and along a length of an inner side surface thereof, such that the grooves of the first and second legs  254   a ,  254   b  face each other. These grooves can have curvatures configured to accommodate, corresponding to, or matching, the curvature or diameter of the threaded rod  114 , such that when the valve gate is assembled, the threaded rod  114  can extend between the first and second legs  254   a ,  254   b , and be positioned at least partially within the grooves such that the legs  254   a ,  254   b  fit at least partially around the curvature of the threaded rod  114 . 
     As illustrated in  FIG.  26   , the first and second legs  254   a ,  254   b  each have square or rectangular cross-sectional shapes when viewed along the central longitudinal axis of the threaded rod  114 . As further illustrated in  FIG.  26   , terminal end portions of the first and second legs  254   a  and  254   b  distal from the spacer  252  include respective sockets  234   a ,  234   b , each of which includes a curved bearing surface. In particular, when viewed along the central longitudinal axis of the pipeline  100 , the first socket  234   a  is spaced apart from the central longitudinal axis of the threaded rod  114  by a first distance in a first direction, and the second socket  234   b  is spaced apart from the central longitudinal axis of the threaded rod  114  by a second distance, which may be the same as the first distance, in a second direction, which may be opposite to the first direction. Each of the sockets  234   a ,  234   b  includes a bearing surface that extends linearly in a direction along a respective axis aligned with or parallel to the central longitudinal axis of the pipeline  100 , and that is curved about such respective axes. Thus, each of the sockets  234   a ,  234   b  forms a respective channel or cup oriented to face downward away from the nut  116  when the valve gate is assembled. Each of the sockets  234   a ,  234   b  can form a respective fulcrum for a respective one of the levers  130  when the valve gate is assembled and in use, as described further elsewhere herein. In some embodiments, the levers  130  may be mounted in the sockets  234   a ,  234   b  on axles. Thus, when taken together with the rest of the movable body  218 , the sockets  234   a ,  234   b  form a terminal end portion of the movable body  218 . 
       FIG.  27    illustrates the seal  220  by itself such that additional features thereof are revealed. As illustrated in  FIG.  27   , the seal  220  is largely the same as the first seal  120 , but the seal  220  includes a first indentation  266   a  formed in an inner surface of a first longitudinally-extending portion thereof that corresponds to the first indentation  166   a  but is located at a slightly different position and oriented upside-down with respect to the indentation  166   a , to accommodate the upside-down re-orientation of the levers  130  and a second indentation  266   b  formed in an inner surface of a second longitudinally-extending portion thereof that corresponds to the second indentation  166   b  but is located at a slightly different position and oriented upside-down with respect to the indentation  166   b , to accommodate the upside-down re-orientation of the levers  130 . 
       FIGS.  20 ,  23 , and  25    illustrate additional details regarding the ways in which the various components of a valve gate including the alternative components engage and interact with one another. As illustrated in  FIGS.  20 ,  23 , and  25   , when the valve gate is assembled, the various components of the valve gate may engage with one another in many of the same ways described herein with respect to the valve gate  104 , with differences noted herein. 
     When assembled, a first curved end of a first one of the levers  130  is positioned within the first socket  234   a  formed in the terminal end portion of the first leg  254   a  of the movable body  218 . Thus, the first one of the levers  130  can rotate, such as either frictionally or without friction by rolling against the curved surface of the first socket  234   a , about an axis aligned with a central longitudinal axis of the pipeline  100  with respect to the other components of the assembled valve gate. Furthermore, a second curved end of the first one of the levers  130  opposite to the first curved end thereof and the socket  234   a  is engaged with and abuts against the outer side surface of the wedges  256   a  and  256   d  such that the wedges  256   a  and  256   d  extend between the second curved end of the first one of the levers  130  and the threaded rod  114 . Additionally, the first one of the levers  130  is positioned such that an outer surface thereof is directly engaged with and abuts against an inner side surface of the seal  220 , for example, such that the protrusion  150  of the first one of the levers  130  is seated snugly within the first indentation  266   a  of the seal  220 . 
     Similarly, when so assembled, a first curved end of a second one of the levers  130  is positioned within the second socket  234   b  formed in the terminal end portion of the second leg  254   b  of the movable body  218 . Thus, the second one of the levers  130  can rotate, such as either frictionally or without friction by rolling against the curved surface of the second socket  234   b , about an axis aligned with a central longitudinal axis of the pipeline  100  with respect to the other components of the assembled valve gate. Furthermore, when the valve gate is assembled, a second curved end of the second one of the levers  130  opposite to the first curved end thereof and the socket  234   b  is engaged with and abuts against the outer side surface of the wedges  256   b  and  256   c  such that the wedges  256   b  and  256   c  extend between the second curved end of the second one of the levers  130  and the threaded rod  114 . Additionally, the second one of the levers  130  is positioned such that an outer surface thereof is directly engaged with and abuts against an inner side surface of the seal  220 , for example, such that the protrusion  150  of the second one of the levers  130  is seated snugly within the second indentation  266   b  of the seal  220 . 
     To actuate and operate the valve gate, such as to move the valve gate into the pipeline  100  through the opening  110  and thereby begin to seal the pipeline  100 , as described elsewhere herein, an operator can actuate the threaded rod  114  to rotate about its own central longitudinal axis by engaging other device(s) with the terminal end portion  144  of the threaded rod  114 , including with the keyway  146  thereof. Actuating the threaded rod  114  to rotate about its own central longitudinal axis, as also described elsewhere herein, causes the nut  116  to travel along the length of the threaded rod  114  and its central longitudinal axis. Because the nut  116  abuts against a terminal end portion of the movable body  218  and the movable body  218  is free to move along the length of the threaded rod  114 , causing the nut  116  to travel along the length of the threaded rod  114  also causes the movable body  218  to travel along the length of the threaded rod  114  and its central longitudinal axis. 
     While the valve gate is being moved into the pipeline  100  through the opening  110 , and before a distal end of the valve gate comes into contact with a surface of the pipeline  100  opposite to the opening  110 , causing movement of the movable body  218  along the length of the threaded rod  114  also causes the rest of the valve gate, including the seal  220 , the levers  130 , the upstream portion of the housing  222 , and the downstream portion of the housing  224 , to move along the length of the threaded rod  114  into the pipeline  100 . Once the valve gate has been moved into the pipeline  100  through the opening  110  and the distal end of the valve gate comes into contact with the surface of the pipeline  100  opposite the opening  110 , however, further distal movement of a distal portion of the seal  220 , the upstream portion of the housing  222 , and the downstream portion of the housing  224  is blocked or prevented by the engagement of the valve gate with the surface of the pipeline  100  opposite the opening  110 . 
     Thus, at this stage, continued movement of the movable body  218  along the length of the threaded rod  114  causes the outer surfaces of the wedges  256   a ,  256   b ,  256   c ,  256   d  to exert forces against the second curved ends of the levers  130 , which, when combined with the engagement of the first curved ends of the levers  130  with the sockets  234   a ,  234   b , causes the levers  130  to pivot or rotate outward with respect to one another and with respect to the threaded rod  114  about their first curved ends engaged with the sockets  234   a ,  234   b . Such rotation may be without friction, in the sense that the curved surfaces of the levers  130  roll along, rather than slide along or rotate against, the curved surfaces of the sockets  234   a ,  234   b.    
     Such outward rotation of the levers  130 , combined with the engagement of the outer surfaces of the levers  130  with the inner surface of the seal  220 , causes the portions of the seal  220  engaged with the levers  130  to move outward, thereby causing the overall profile of the valve gate when viewed along the central longitudinal axis of the pipeline  100  to expand, such as to a profile that is larger than the opening  110  in the pipeline  100 . In particular, because the outer surfaces of the wedges  256   a ,  256   b ,  256   c , and  256   d  exert forces against the levers  130  at locations farther from the sockets  234   a ,  234   b  than the locations at which the levers  130  engage with the inner surface of the seal  220 , the forces applied by the levers  130  to the seal  220  are larger than the forces applied by the wedges  256   a ,  256   b ,  256   c ,  256   d  to the levers  130  and the travel of the portions of the seal  220  engaged with the levers  130  is smaller than the travel of the ends of the levers  130  engaged with the wedges  256   a ,  256   b ,  256   c ,  256   d.    
     While the seal  220  is expanding radially outward with respect to the central longitudinal axis of the pipeline  100 , and before the seal  220  fully engages with the inner surface of the pipeline  100  to form a complete seal therewith, continued movement of the movable body  218  along the length of the threaded rod  114  causes continued outward rotation of the levers  130  and continued expansion of the seal  220  radially outwards with respect to the central longitudinal axis of the pipeline  100 . Once the seal  220  fully engages with the inner surface of the pipeline  100  and forms a complete seal therewith, however, further expansion of the seal  220  is blocked or prevented by the engagement of the seal  220  with the inner surface of the pipeline  100 . At this stage, rotation of the threaded rod  114  can be ceased and the actuation of the valve gate to seal the pipeline  100  is complete. In this configuration, the valve gate is in an engaged, inserted, closed, and sealed position or configuration. 
     To actuate and operate the valve gate, such as to retract the valve gate by moving the valve gate out of the pipeline  100  through the opening  110 , as described elsewhere herein, an operator can actuate the threaded rod  114  to rotate about its own central longitudinal axis by engaging other device(s) with the terminal end portion  144  of the threaded rod  114 , including with the keyway  146  thereof, such that the threaded rod  114  rotates in a direction opposite to that used to insert the valve gate. Such rotation of the threaded rod  114  acts to move the components of the valve gate in directions opposite to those described above for the insertion of the valve gate. For example, in a first step, the seal  220  is retracted into the rest of the valve gate and the overall profile of the valve gate as viewed along the central longitudinal axis of the pipeline  100  decreases, such as to a profile that is smaller than the opening  110  in the pipeline  100 . As another example, in a second step, the valve gate may be retracted from the pipeline  100  through the opening  110  therein. Such actions can be used to move the valve gate to a disengaged, retracted, withdrawn, open, and unsealed position or configuration. Inserting and retracting the valve gate to seal and unseal the pipeline  100  can be repeated as desired. 
     One advantage of the valve gates described herein is that they are configured to seal a variety of different pipelines even if those pipelines have different inside diameters, or even if a pipeline to be sealed has a variable inside diameter or an inside diameter that is not precisely known. In particular, because the valve gates described herein create a seal by expanding radially outward until they engage with an inner surface of the pipeline, the valve gates described herein can be expanded by an amount tailored to the specific inner diameter of the pipeline to be sealed, and even to the specific inner diameter at the specific location at which the pipeline is to be sealed. 
     For example, a single one of the valve gates described herein may be capable of sealing pipelines having inner diameters that range over at least one eighth of an inch, one quarter of an inch, or three eighths of an inch, such as without any changes made to the valve gate itself other than different amounts of expansion applied to the seal thereof. Furthermore, the valve gates described herein may be configured to seal pipelines having inner diameters between three inches and five inches, between five inches and seven inches, between seven inches and nine inches, between nine inches and eleven inches, between eleven inches and thirteen inches, between thirteen inches and fifteen inches, between fifteen inches and seventeen inches, between seventeen inches and nineteen inches, between nineteen inches and twenty one inches, between twenty one inches and twenty three inches, or between twenty three inches and twenty five inches. 
     The valve gates described herein have been described primarily in the context of live pipeline valve insertion, but the valve gates described herein can also be used in installed-in-place valves or valves that are initially installed in new pipeline systems, such as within a traditional wedge-style gate valve. In such embodiments, certain differences from the preceding description would apply. For example, in such embodiments, the valve gate may be oriented at 90 degrees with respect to the pipeline to be sealed as compared to its orientation with respect to the pipeline  100  illustrated and described above with respect to live pipeline valve insertion. Thus, in such embodiments, the valve gate may be configured such that an axis along which the seal of the valve gate expands is aligned with or parallel to a central longitudinal axis of the pipeline to be sealed, and/or such the valve gate may be configured to form a seal with at least a portion of an axially-facing end surface of the pipeline to be sealed. Furthermore, in such embodiments, a valve including the valve gate may also include a valve seat such that the terminal distal end of the valve gate engages with the valve seat when the valve is closed. 
     The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.