Patent Application
20130098473
The subject matter disclosed herein relates to tool for removing and installing plugs in a conduit and in particular to a tool for use with pipes having a pressurized gas therein.
Pressurized piping is commonly used to transport a fluid, such as natural gas for example, to an end use location. In natural gas applications, a gas main is often installed under or adjacent to a roadway with connection joints, sometimes referred to as a “service tee”, are installed periodically along the gas main. The connection joint includes a first pipe that extends at a right angle to the gas main. A second or service pipe extends from the first pipe and extends to the end use location, such as a residential home for example.
The end of the first pipe is closed by a plug that is press fit into the inner diameter of the first pipe. The plug has a threaded hole facing the exterior. In the event that service personnel need to open the connection joint, such as to shut off service to the service pipe for example, a bolt is attached to the threaded hole. The service personnel then manually remove the plug by pulling on the bolt until the plug is worked free. It should be appreciated that the gas main and the connection joint are under pressure. Commonly, natural gas distribution systems operate from ½ lb to 60 pounds. As a result of this pressure, once the plug is removed, natural gas will escape from the opening into the environment. Service personnel then have to work quickly to insert a smaller plug that can be inserted between the gas main and the service pipe to prevent further leakage of natural gas.
While existing tools and methods of removing plugs from connection joints are suitable for their intended purposes a need for improvement remains, particularly in providing a tool that allows the removal of the plug from the connection joint with little or no leakage of the pressurized gas.
According to one aspect of the invention, a tool for extracting a plug is provided. The tool includes a chamber member having an open end and a closed end, the closed end having a bore therethrough. An extractor member having a handle on one end and a shaft portion extends through the bore, the shaft portion having at least first threaded portion opposite the handle and a second threaded portion adjacent the closed end. A lifting member is operably coupled to the second threaded portion.
According to another aspect of the invention, another tool for extracting a plug is provided. The tool includes a valve. A chamber member having a first end is coupled to the valve and a second end, the chamber member having a substantially hollow interior portion, the second end having a bore therethrough. An extractor member having a shaft portion is slidably coupled to and at least partially disposed within the bore, the extractor member having a fastener portion on one end and a lifter portion adjacent the second end. A lifting member is operably coupled to the lifter portion.
According to yet another aspect of the invention, a method of extracting a plug from a natural gas service connection is provided. The method includes providing a tool having a chamber member having an open end and a closed end, the closed end having a bore therethrough. An extractor member is provided for the tool having a handle on one end and a shaft portion extending through the bore, the shaft portion having at least first threaded portion opposite the handle and a second threaded portion adjacent the closed end. A lifting member is provided for the tool operably coupled to the second threaded portion. A valve is removably coupled to the open end.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
Embodiments of the present invention provide for a the removal and installation of plugs within a connection joint, such as those used in natural gas distribution systems. These embodiments provide advantages in allowing removal of the plug and installation of a new plug with little or no leakage of natural gas from the system.
A typical connection joint 20 is shown in
Extending from the first pipe 24 is a second pipe 36. It should be appreciated that the second pipe 36 is positioned between the plug 30 and an opening 38 from the gas main 22 into the first pipe 24. As will be discussed in more detail below, the service pipe 36 may be offset from the gas main 22 to provide an area 40 that allow a plug to be inserted and disconnect the service pipe 36.
Referring now to
The extractor 62 includes the shaft 58 that is slidably disposed within the bore 56. The shaft 58 extends through the chamber member 44 and has a threaded portion 64. The threaded portion 64 is sized to couple with the threaded hole 34 of plug 30. The shaft 58 further includes a second threaded portion 66. In one embodiment, the shaft 58 has a thread extending along substantially the entire length of the shaft to form a continuous screw thread. A lifting member 68 is coupled to the second threaded portion 66 adjacent the top surface of the cap 50. On one end, the extractor 62 includes a handle 70, such as a T-handle.
As will be discussed in more detail below, in the exemplary embodiment, the lifting member 68 is a nut that has an internal screw thread that engages the second threaded portion 66. The nut may be moved against the top surface of the cap 50 such that the rotation of the nut will cause the extractor 62 to translate relative to the chamber member 44 and pull the plug 30 from the connection joint 20. In other embodiments, the lifting member may be a ratchet type mechanism that engages teeth on the extractor 62 to cause movement. In still other embodiments, the lifting member may be incorporated into the cap such as by threads in the bore 56 for example.
As shown in
In operation, the service personnel typically first dig or otherwise expose the connection joint 20. The cap 30 is removed and the valve 72 is coupled to the first pipe 24. The chamber member 44 is coupled to an end of the valve 72 opposite the first pipe 24. The valve assembly 76 is opened and the shaft portion 58 is inserted through the valve assembly 76 allowing the threaded end 64 to engage the threaded hole 34 in plug 30 (
With the extractor 62 coupled to the plug 30, the lifting member 68 is rotated against the top surface of the cap 50. Once the lifting member 68 is against the cap 50, further rotation of the lifting member 68 causes the extractor 62 to move in a direction away from the connection joint 20. As the extractor 62 moves, the plug 30 will be removed from the first pipe 24. Continued rotation of the lifting member 68 results in the plug 30 passing through the valve assembly 76 and into the interior portion 52 of chamber member 44. With the plug 30 within the chamber member 44, the valve assembly 76 may be actuated to the closed position (
In one embodiment, the chamber member 44 includes a relief valve 45. With the valve 72 closed, the relief valve 45 may be activated to release a small amount of pressurized gas from within the interior volume 52. The chamber member 44 may then be removed from the valve 72 and the plug 30 detected from the extractor 62. It should be appreciated that since the valve 72 is closed, that substantially no natural gas will leak from the gas main when the chamber member 44 is removed.
With the plug 30 detached, the service personnel may then attach a new plug 80, sometimes referred to as a stopper unit 80 (
One embodiment of the stopper unit 80 is shown in
It should be appreciated that the stopper unit 80 will remain compressed only when the installation tool 82 is coupled to the stopper unit 80. This provides advantages in allowing the stopper unit to be easily and repeatably installed and removed be service personnel.
In another embodiment, the stopper unit is a 2 inch Expander Plug Model manufactured by Mueller Company. Unlike the stopper plug described above, the Expander Plug may be permanently installed in the pipe 24 since the Expander Plug is configured to remain in the sealed position when the installation tool is decoupled.
To install the stopper unit 80, the installation tool 82 is inserted through the bore 56 and into the chamber member 44. The stopper unit 80 is coupled to the end 86 and moved into the interior portion 52. The chamber member 44 is then coupled to the valve 72 and the valve assembly 76 is opened. With the valve assembly 76 open, the threaded rod portion 84 and stopper unit 80 may be inserted through the valve 72 until the stopper unit 80 is positioned in area 40 between the service pipe 36 and the gas main 22. The stopper unit 80 is then actuated by rotating the extractor 62 causing the stopper unit 80 to seal against the inner diameter of the first pipe 24. With the stopper unit 80 installed, the service pipe 36 is isolated from the gas main 22 and service work may be commenced on the line. Once the service work is complete, the process may be reversed with the stopper unit 80 being moved into the chamber member 44, the valve 72 closed. The chamber member 44 is removed from the valve 72 to retrieve the stopper member 80. The plug 30 may be reinstalled using the extractor 62, attaching the chamber member 44 to the valve 72. The valve 72 is opened and the plug 30 pressed back into the first pipe 24. In some embodiments, the service personnel may tap the extractor 62 with a mallet to obtain the desired seating of the plug 30. The extractor 62 is then removed from the plug 30 and the valve 72 and tool 42 detached from the connection joint 20. Finally, the cap 32 reattached to the first pipe 24.
It should be appreciated that while embodiments herein refer to a natural gas distribution system, the claimed invention should not be so limited and embodiments of the present invention may be used in any application having a pressurized gas being carried by a conduit where a plug needs to be removed while reducing or eliminating leakage during the extraction.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
