Abstract:
An apparatus and method are provided for installing a fluid tap onto a pipe or conduit containing pressurized fluid. Debris generated by cutting a coupon from a pressurized fluid conduit is directed though the apparatus and prevented from entering the conduit. The apparatus can be removed from the newly installed air tap and reused. According to the method, pressurized fluid from the pressurized fluid system is used to wash debris generated from the coupon-cutting operation through the apparatus along a flow path that includes a collection chamber and filter. A kit is also provided and includes the apparatus and a variety of interchangeable connectors and cutting tools to allow the apparatus to be quickly configured for a wide variety of tap, valve, and pipe sizes.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of prior U.S. Provisional Application No. 60/193,456 entitled “Method and Device for Installing an Air Tap onto a Pressurized Air Pipe” filed Mar. 31, 2000, which is incorporated herein in its entirety by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus and method for installing an air tap onto a pipe containing pressurized fluid. 
     When compressed fluid systems such as compressed air systems have been in service and require modification, such as tapping an additional pipe onto an existing pipe, conventional methods typically require that a section of the pipe being worked must be isolated or the entire compressed fluid system must be shutdown and depressurized before an air tap is added. As a result, any equipment or processes depending on the compressed fluid must be taken out of service or shifted to an alternate supply. In addition, any cuttings and debris generated by cutting the existing pipe often enter the pipework, contaminating the fluid system and causing potential problems to filters, tools, and other equipment. 
     U.S. Pat. No. 5,964,240 to Granovski relates to a pipe tapping device for attaching a branch device to a main pipeline without disconnecting or interrupting the flow through the main pipeline. The apparatus is used for only a single application and the saddle, valve, and cutting tool of the device constitute an integral assembly that becomes a permanent part of the system onto which the apparatus is installed. 
     A need exists for a pipe tapping system that can use an off-the-shelf saddle and valve which become a permanent part of the compressed fluid system without the need to permanently include the tapping or cutting tool in the system. 
     A need further exists for a reusable pressurized fluid pipe tapping apparatus that can be used many times and thus is less expensive to use than tapping or cutting tools that can only be used one time. 
     SUMMARY OF THE INVENTION 
     The present invention provides an apparatus and method for connecting a pipe for an ancillary device or system to the outside wall of an existing pipe by using a fitting and valve connection. According to the present invention, a saddle or connecting plate is mounted to an existing pipe and a flow valve is connected to the connecting plate and set to an open position. The tapping apparatus of the present invention is connected to the valve and includes a cutting bit that extends though the valve, through the connection plate, and contacts the existing pipe where it cuts a coupon from the existing pipe and catches the coupon. After the coupon is cut from the side wall of the existing pipe, the coupon and cutting bit are removed from the valve and the valve can be closed to facilitate removal of the tapping device from the valve. The tapping device including the cutting bit can then be disconnected from the valve and removed to be used again. 
     The design of the tapping apparatus provides for the collection of cutting debris in a chamber in the apparatus and prevents the debris from entering the compressed air system being tapped. Energy from the compressed air in the pipe system is used to wash the debris through the apparatus along a flow path having a chamber design. A filter is provided within the tapping apparatus to trap cuttings and finer debris yet allow air to purge from the apparatus. Compressed fluid flowing through the apparatus exits the apparatus through a miniature muffler. 
     The apparatus can be provided in a kit according to the present invention which includes interchangeable adapters, connectors, and cutting tools to quickly configure the apparatus for a wide variety of tap and pipe sizes. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are only intended to provide a further explanation of the present invention, as claimed. The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate several exemplary embodiments of the present invention and together with description, serve to explain the principles of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may be more fully understood with reference to the accompanying figures. The figures are intended to illustrate exemplary embodiments of the present invention without limiting the scope of the invention. 
     FIG. 1 is a cross-sectional side view of a tapping tool of the present invention operatively connected to a valve, which in turn is connected to a connection plate, which in turn in mounted on a pipe to be tapped; 
     FIG. 2 is a cross-sectional view of a tapping tool according to an embodiment of the present invention; 
     FIG. 3A is a plan view of a {fraction (13/16)} inch drill bit useful in an apparatus according to an embodiment of the present invention; 
     FIG. 3B is an end view of the drill bit  71  taken along line  3 B— 3 B of FIG. 3A; 
     FIG. 3C is an end view of drill bit  71  taken along line  3 C— 3 C of FIG. 3A; 
     FIG. 4A is a plan view of a 1 and {fraction (7/16)} inch cutting bit useful in an apparatus according to an embodiment of the present invention; 
     FIG. 4B is an end view of the drill bit taken along line  4 B— 4 B of FIG. 4A; 
     FIG. 4C is an end view of the drill bit taken along line  4 C— 4 C of FIG. 4A; 
     FIG. 5A is a plan view of a {fraction (3/16)} inch pilot drill bit having a coupon catch design and useful in the apparatus according to the present invention; 
     FIG. 5B is an end view of the pilot bit taken along line  5 B— 5 B of FIG. 5A; 
     FIG. 6 is a plan view of the pilot bit shown in FIGS. 5A and 5B and shows the various dimensions of the pilot bit; 
     FIG. 7A is a plan view of a ½ inch twist drill bit shown in partial breakaway and suitable for use in an apparatus according to the present invention; 
     FIG. 7B is an end view of the twist drill bit taken along line  7 B— 7 B of FIG. 7A; 
     FIG. 7C is an end view of the twist drill bit taken along line  7 C— 7 C of FIG. 7A; 
     FIG. 8A is a ⅝ inch twist drill bit shown in breakaway view, that can be used in an apparatus according to an embodiment of the present invention; 
     FIG. 8B is an end view of the twist drill bit taken along line  8 B— 8 B of FIG. 8A; 
     FIG. 8C is an end view taken along line  8 C— 8 C of FIG. 8A; 
     FIG. 9 is a plan view of a tap kit according to an embodiment of the present invention; 
     FIG. 10 is a plan view of a tap kit according to an embodiment of the present invention; 
     FIG. 11 is a side plan view of a ¾ inch NPT connector according to an embodiment of the present invention; 
     FIG. 12 is an end view of the connector taken along line  12 — 12  of FIG. 11; 
     FIG. 13 is a side plan view of a 1 inch NPT connector according to an embodiment of the present invention; 
     FIG. 14 is an end view of the connector taken along line  14 — 14  of FIG. 13; 
     FIG. 15 is a side view of an end cap used in an apparatus according to an embodiment of the present invention; 
     FIG. 16 is an end view taken along line  16 — 16  of FIG. 15; 
     FIG. 17 is an end view taken along line  17 — 17  of FIG. 15; 
     FIG. 18 is a side plan view of a 1 and ½ inch NPT connector used in an apparatus according to an embodiment of the present invention; 
     FIG. 19 is an end view of the connector taken along line  19 — 19  of FIG. 18; 
     FIG. 20 is an end view of a filter used in an apparatus according to an embodiment of the present invention; 
     FIG. 21 is a side view of the pleated filter of FIG. 20; 
     FIG. 22 is a cutaway side view of a tap body of an apparatus according to an embodiment of the present invention; 
     FIG. 23 is an end view taken along line  23 — 23  of FIG. 22; 
     FIGS. 24-26 show various end views and a side phantom view of a tap body useful in an apparatus according to an embodiment of the present invention; 
     FIG. 27 is a plan view of a drill bit including a cutting bit without a pilot bit, shown in breakaway view, useful in an apparatus according to an embodiment of the present invention; 
     FIG. 28 is an end view taken along line  28 — 28  of FIG. 27; 
     FIG. 29 is an end view taken along line  29 — 29  of FIG. 27; 
     FIG. 30 is a plan view of a drill bit including a cutting bit without a pilot bit, shown in breakaway view, useful in an apparatus according to an embodiment of the present invention; 
     FIG. 31 is an end view taken along line  31 — 31  of FIG. 30; 
     FIG. 32 is an end view taken along line  32 — 32  of FIG. 30; 
     FIG. 33 is a side plan view of a ¾ inch connector used in an apparatus according to an embodiment of the present invention; 
     FIG. 34 is an end view of the connector taken along line  34 — 34  of FIG. 33; 
     FIG. 35 is a side view of a 1 inch connector used in an apparatus according to an embodiment of the present invention; 
     FIG. 36 is an end view of the connector taken along line  36 — 36  of FIG. 35; 
     FIG. 37 is a side view of a 1 and ½ inch connector used in an apparatus according to an embodiment of the present invention; and 
     FIG. 38 is an end view of the connector taken along line  38 — 38  of FIG.  37 . 
    
    
     DETAILED DESCRIPTION 
     According to the present invention, a tapping tool is provided for tapping a pressurized fluid from within an existing conduit to an ancillary device. The tapping tool includes a tool body having opposing ends, at least one of the ends having an opening, an interior cavity, and at least one shaft mounting means or device, such as a bearing or bushing. The shaft mounting means rotatably mounts a shaft of a hole cutting means, such as a drill bit, in a fixed axis of rotation with respect to the tool body while allowing sliding movement of the shaft along the axis of rotation. The tapping tool also includes a hole cutting means or device, such as a drill bit, having a shaft and a cutting bit at one end of the shaft. The shaft preferably has a diameter such that the shaft fits in the at least one shaft mounting means for rotation about the fixed axis of rotation. The shaft preferably has a length sufficient to allow the cutting bit to extend through the opening in the tool body and remain mounted by the at least one shaft mounting means when the hole cutting means is operatively positioned within the tool body. The tapping tool of the present invention may also preferably include a driving means or device, such as a drill, connected to an end of the shaft of the hole cutting means opposite the end of the shaft having the cutting bit. 
     According to some embodiments of the present invention, the tapping tool may also include a connecting means, such as a connector or nipple, that has an interior cavity and opposing ends, wherein one end of the connecting means has connection means or a connecting device, such as threads, for connecting to the end of the tool body having the opening. The opposite end of the connecting means may also have connection means or a connecting device, such as threads, for connecting to an end of a valve means, such as a full flow ball valve. In embodiments wherein the connecting means is connected to the tool body, the shaft of the hole cutting means preferably has a length sufficient to allow the cutting bit to extend through the connecting means while the shaft remains mounted by the at least one shaft mounting means and the hole cutting means is operatively positioned within the tool body. 
     The tapping tool of the present invention, when in operative position, may further includes a removable valve means, such as a full flow ball valve, connected to the end of the tool body having the opening. The tapping tool can also include a removable valve mounting means, such as a saddle, connecting plate, or other connector connected to the valve means for mounting the valve means to an existing conduit of a pressurized fluid system. The cutting bit in such an embodiment preferably extends through the valve means and through the valve mounting means in operation, to reach the existing pipe or conduit onto which the valve mounting means is secured. 
     In embodiments wherein a tool body connecting means is also included, the valve means may be removably connected to the connecting means at a first end of the connecting means. The connecting means preferably also has an interior cavity and a second end opposite the first end. The second end of the connecting means is connected to the end of the tool body having the opening. When the driving means is actuated, the shaft can be slid through the shaft mounting means such that the cutting bit extends through said connecting means, through the valve means, through the valve mounting means, and into contact with the existing conduit to cut a coupon out of the existing conduit. When the cutting bit pierces the existing conduit, pressurized fluid from the conduit flows through the valve mounting means, through the valve means, through the connecting means, through the interior cavity of the tool body, and out an exhaust means, such as an exhaust port formed in the tool body. 
     The tapping tool preferably includes exhaust means communicating the interior cavity of the tool body with the surrounding atmosphere. Preferably, the interior cavity is designed to permit the flow of pressurized fluid through the opening, through the interior cavity, and out the exhaust means. The interior cavity is preferably substantially air-tight from the opening to the exhaust means, and a filter is preferably provided in the interior cavity for filtering pressurized fluid flowing through the tool body and out the exhaust means. 
     The present invention also provides a kit that includes the tapping tool and at least a second hole cutting means that is different from the first hole cutting means included with the tool. Preferably, the kit also includes at least two connecting means that differ from one another. 
     The present invention also includes a method for tapping a pressurized fluid from within a conduit to an ancillary device. The method includes mounting a first end of a valve means to a pressurized fluid conduit. The valve means has a first end, a second end, and a through hole extending from the first end to the second end when the valve means is in an open position. The valve means is actuated to an open position if not mounted in an open position. Mounting the valve means may include mounting a valve mounting means such as connection plate or saddle on a pipe or conduit and connecting the valve means to the valve mounting means before or after mounting the mounting means. 
     A tapping tool according to the present invention is removably connected such that the end of the tool body having the opening is connected to a second end of the valve means. A driving means such as a drill is connected to the driving head of the shaft of the hole cutting means. The cutting bit of the hole cutting means is then extended through the valve means and into cutting contact with the conduit. A hole is then cut by the hole cutting means in the existing conduit. Then, the hole cutting means is withdrawn from the valve means. The valve means is then closed after the hole cutting means is withdrawn. Afterwards, the tapping tool can be disconnected from the second end of the valve means. 
     The tapping tool may also include a pilot bit integral with or removably secured or mounted on the end of the hole cutting means that includes the cutting bit. The pilot bit preferably pilots the cutting bit and rotates on the same axis of rotation as the cutting bit. The method preferably includes first cutting a pilot hole with the pilot bit and then cutting a coupon with the cutting bit, wherein the pilot bit includes a catch that retains the coupon after it is cut with the cutting bit and during withdrawal of the cutting bit from the valve means. Pressurized fluid from the pressurized fluid conduit forces debris and cuttings from the cutting operation through the valve means and into the interior cavity of the tool body. The tool body may further include an exhaust means, such as an exhaust port, communicating the interior cavity with the surrounding atmosphere, and the flow of pressurized fluid flows through the interior cavity and out the exhaust means. The interior cavity is substantially air-tight from the first opening to the exhaust means, and a filter is provided in the interior cavity for filtering pressurized fluid flowing through the tool body and out the exhaust means. 
     The end cap on the tool body facilitates cleaning cutting debris from the interior cavity of the body and enables replacement of the filter. In this regard, the cap for the tool body is preferably installed using a stainless steel anti-seize lubricant on the threads to avoid galling and damage to the stainless steel threads. Bearings, bushings, and seals can also be replaced as necessary by periodically taking apart the various tool components. 
     A properly sized drill bit or cutting bit can be installed by sliding the shaft of the bit through the front of the tool until the cutting end is withdrawn into the tool body or a connector for the tool body. Various driving means, including a ⅜ inch chuck or larger drill, can preferably be used to operate the tool. 
     An exemplary operation begins by installing a connecting plate onto an existing conduit or pipe and tightening the plate to the conduit. Preferably, a valve, such as a full flow ball valve, is then installed onto the connecting plate that is already mounted on the existing conduit. Thread sealant and adequate torque should be used to tighten the valve and connecting plate as these components will remain a permanent part of the system. The tapping tool of the present invention is threaded into the exposed end of the valve, that is, the end of the valve opposite the end secured to the connecting plate. The valve is set to an open position and the cutting bit is slid through the tapping tool until it touches the wall of the pipe. A variable speed drill, for example, a drill having a ⅜ inch chuck or larger, is then attached to the cutting bit and drilling is performed at a proper speed. When the pipe is cut through, cutting debris is collected into the tool body and if a coupon blank is made, the coupon is preferably trapped on the pilot drill bit. Then, the cutting bit is carefully retracted through the valve so as to not damage the valve or shake any remaining debris into the system. The valve is then closed. 
     After the ball valve is closed, the tapping tool is preferably slowly removed from the valve by disengaging the threads. Each connector or attachment nipple preferably has a small slot cut into an end of the pipe threads which acts as a safety pressure relief and whistles to alert the user of pressure and to relieve the pressure. If pressure begins to relieve in this way, removal of the tool should be stopped until all pressure is relieved. After ensuring that the valve is fully closed and the safe removal of the tapping tool is completed, the tool can be disassembled, cleaned, and components can be replaced if necessary. After tool removal, a new pipe or conduit can then be installed onto the newly installed valve. 
     Referring now to the drawing figures, the abbreviation NPT is for National Pipe Thread standard and the abbreviation BSPT is for British Pipe Thread Tapered. FIG. 1 shows a tapping tool  30  according to an embodiment of the present invention operatively connected to a flow valve  32 , which in turn is threadably engaged to a mounting plate  34  which has been secured to a pipe  36 . The pipe may be of the type described in U.S. Pat. No. 5,938,245, which is incorporated herein in its entirety by reference. The flow valve can be a full flow ball valve, for instance, a PARKER ball valve. The connection plate  34  is secured to the pipe  36  by bolts  38  and nuts  40  in the embodiment shown. The tapping tool  30  according to the present invention includes a quick change connector  42  having at an end thereof threads  44  that engage threads  46  of the flow valve  32 . The opposite end of the quick change connector  42  is provided with threads  48  that engage tap body  50  at threads  52 . An anti-rotation lock  54  is provided to prevent the rotation of body  50  relative to the quick change connector  42 . The anti-rotation lock  54  is provided with a pin  56  and is spring biased by a spring  57 , such that pin  56  is normally biased into one of a plurality of pin receiving holes  58  formed in the quick change connector  42 . Tap body  50  has a flow through cavity  60  formed therein that is in communication with a cavity  62  in the interior of quick change connector  42 . Cavity  60  in tap body  50  is provided with a chip collection chamber  64 . Chip collection chamber  64  is adjacent a filter  66 , as shown. Tap body  50  is provided with bearings  68  at one end thereof and bearings  70  at an opposite end thereof. Bearings  68  and  70  assure a very precise alignment of a drill shaft  72  of drill bit  71  that passes through the tap body  50  and is guided and rotatably secured by bearings  68  and  70 . Preferably, bearings  68  and  70  comprise a durable, low friction material and can be ball bearings, rail bearings, rod bearings, polytetrafluoroethylene bearings, or other bearings conventional to those skilled in the art. The bearings are preferably interference fit within the tap body  50 . Adjacent bearing  70  in tap body  50  is an exhaust port  74  for exhausting pressurized gas forced through the tap body  50  by the pressure of compressed air or fluid passing through pipe  36 . Exhaust port  74  leads to a muffler or silencer  76  from which pressurized air, other gas, or fluid can be exhausted from tap body  50 . 
     At a first end of drill shaft  72 , the shaft  72  is connected to a power drill  78 , for example, any conventional power drill having a drive suitable for accommodating the drill shaft  72 . At an end of drill shaft  72  opposite the power drill  78 , a cutting bit  80  is provided, for example, a carbide hole cutter bit. Axially centered with respect to the cutting bit  80  is a pilot drill bit  82  that includes a coupon catch  84  for catching a coupon resulting from a hole cutting operation with bit  80 . The coupon catch  84  assures that the coupon is not lost into a pressurized fluid system to which pipe  36  is connected. Hole cutting bit  80  is preferably provided with a design that guides or forces cuttings from a hole cutting operation into a cavity  86  formed internally of the connection plate  34  and flow valve  32 . 
     In the embodiment shown in FIGS. 1 and 2, tap body  50  is provided with and includes an end cap  51  having threads  53  that threadably engage the tap body proper  50  at threads  55 . 
     As shown in FIG. 2, an O-ring  90  is provided between the tap body  50  and the quick change connector  42  to provide an air-tight seal at the connection of the two components. A seal  92  is also provided adjacent bearing  68  to prevent the escape of pressurized fluid from the tap body along drill shaft  72 . The seal  92  and the O ring  90  preferably comprise a rubber or other elastomeric or resilient material, for example, a carboxylated nitrile material. 
     In operation, a connecting plate  34  is mounted to a pipe  36  to be tapped. O-rings, seals, gaskets, or other insulating material and/or means can be provided between the connection plate  34  and pipe  36  to provide an air-tight seal therebetween. A flow valve  32  is connected to the connection plate  34  before or after the connection plate  34  is secured to the pipe  36 . Threading compound, sealing tape, or other sealing material and/or means are preferably provided at the point of engagement between the flow valve  32  and the connection plate  34 . According to the embodiment shown in FIG. 1, a sealing compound is provided where the threads of flow valve  32  engage the threads of connection plate  34 . The quick change connector  42  is threadably engaged at threads  44  to threads  46  of the flow valve  32 , before or after the flow valve  32  is engaged with connection plate  34 . The tap body  50 , including end cap  51 , is engaged with the connector  42 , and the anti-rotation lock  54  is engaged in an appropriate pin receiving hole  58 . Tap body  50  is preferably threadably engaged to the quick change connector  42  after connector  42  is engaged to the flow valve  32 . The device is ready for operation. 
     As drill  78  actuates drill shaft  72  to spin the cutting bit  80  and pilot bit  82 , pilot bit  82  begins to drill through the side wall of pipe  36 . Due to the shape of the grooved channels formed in pilot bit  82 , cuttings from drilling with the pilot bit are generally directed in a direction opposite the direction of drilling, that is, away from pipe  36 . Once the pilot drill bit  82  pierces the side wall of pipe  36 , compressed or pressurized fluid traveling through pipe  36  begins to seep through the newly formed pilot drill bit hole causing the further carrying way of cuttings and debris in a direction opposite the direction of drilling. Pressurized fluid seeping through the newly formed hole passes through cavity  86 , through cavity  62 , into cavity  60 , through filter  66 , through exit port  74 , and out the muffler or silencer  76 . Large chips or chunks of debris are collected in the chip collection chamber  64  whereas smaller debris may be trapped by filter  66 . 
     After the pilot drill bit  82  penetrates the side wall of pipe  36 , hole cutting bit  80  begins to abrade or cut the side wall of pipe  36 . Debris resulting from the hole cutting operation using bit  80  passes along with the flow of pressurized fluid through cavity  86 , through cavity  62 , through cavity  60 , and is trapped in either chip collection chamber  64  or by filter  66  while the pressurized fluid escapes the tapping tool  30  through exhaust port  74  and muffler or silencer  76 . 
     FIG. 3A is a plan view of a {fraction (13/16)} inch drill bit according to an embodiment of the present invention. The shaft of the bit is preferably made of a hardened metal such as hardened or stainless steel, and the cutting tip may preferably be a carbide cutting tip. FIG. 3B is an end view of the drill bit  71  of FIG. 3A taken along line  3 B— 3 B, and FIG. 3C is an end view of drill bit  71  taken along line  3 C— 3 C of FIG.  3 A. 
     FIG. 4A is a plan view of a 1 and {fraction (7/16)} inch cutting bit used in according to an embodiment of the present invention. The shaft of the bit is preferably made of a hardened metal such as hardened or stainless steel, and the cutting tip may preferably be a carbide cutting tip. FIG. 4B is an end view of the drill bit of FIG. 4A taken along line  4 B— 4 B and FIG. 4C is an end view of the drill bit  71  of FIG. 4A taken along line  4 C— 4 C of FIG.  4 A. 
     FIG. 5A is a plan view of a {fraction (3/16)} inch pilot drill bit having a coupon catch design and useful in the apparatus according to the present invention. FIG. 5B is an end view of the pilot bit shown in FIG. 5A taken along line  5 B— 5 B of FIG.  5 A. FIG. 6 is a plan view of the pilot bit shown in FIGS. 5A and 5B and shows the various dimensions of the pilot bit. In FIGS. 5A,  5 B and  6 , all dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for line  5 B— 5 B and reference numerals  110  and  111 . Reference numeral  110  designates a ¼-20 H3 spiral flute plug chamfer on the pilot bit and  111  designates a #7 wire, 118° split point on the pilot bit. The material of the bit is preferably a high speed tool steel. Unless otherwise shown, all radii are 0.015 inch. 
     FIG. 7A is a plan view of a ½ inch twist drill bit shown in partial cutaway and suitable for use in an apparatus according to the present invention. FIG. 7B is an end view of the twist drill bit shown in FIG. 7A taken along line  7 B— 7 B of FIG.  7 A. FIG. 7C is an end view of the twist drill bit of FIG. 7A, taken along line  7 C— 7 C in FIG.  7 A. In FIGS. 7A,  7 B and  7 C, all dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for lines  7 B— 7 B and  7 C— 7 C, and reference numerals  113  and  114 . Reference numeral  113  designates a ½ inch twist drill with a 118° point and  114  designates a flatly ground surface, three of which are equally spaced around the circumference of the shaft. The material of the bit is preferably a high speed tool steel. Unless otherwise shown, all radii are 0.06 inch. 
     FIG. 8A is a ⅝ inch twist drill bit shown in breakaway view, that can be used in an apparatus according to an embodiment of the present invention. FIG. 8B is an end view of the twist drill bit of FIG. 8A taken along line  8 B— 8 B of FIG.  8 A. FIG. 8C is an end view taken along line  8 C— 8 C of FIG.  8 A. In FIGS. 8A,  8 B and  8 C, all dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for lines  8 B— 8 B and  8 C— 8 C, and reference numerals  115  and  116 . Reference numeral  115  designates a ⅝ inch twist drill with a 118° point and  116  designates a flatly ground surface, three of which are equally spaced around the circumference of the shaft. The material of the bit is preferably a high speed tool steel. Unless otherwise shown, all radii are 0.06 inch. 
     FIG. 9 is a plan view of a tap kit according to an embodiment of the present invention. The kit includes a {fraction (13/16)} inch cutting bit  120 , a ½ inch twist drill bit  121 , a ⅝ inch twist drill bit  122 , a ¾ inch BSPT connector  123 , a 1 inch BSPT connector  124 , a tapping tool  125  including a 1 and {fraction (7/16)} inch cutting bit, and a carrying case  126 . 
     FIG. 10 is a plan view of a tap kit according to an embodiment of the present invention. The kit includes a {fraction (13/16)} inch cutting bit  130 , a ½ inch twist drill bit  131 , a ⅝ inch twist drill bit  132 , a ¾ inch NPT connector  133 , a 1 inch NPT connector  134 , a tapping tool  135  including a 1 and {fraction (7/16)} inch cutting bit, and a carrying case  136 . 
     FIG. 11 is a side plan view of a ¾ inch NPT connector according to an embodiment of the present invention and FIG. 12 is an end view of the connector taken along line  12 — 12  of FIG.  11 . The connector is preferably made of a 300 series stainless steel material. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for line  12 — 12 , and reference numerals  140  and  141 . Reference numeral  140  designates a slot having a 2.31 inch outer diameter and a 0.41 inch deep from the back side, and having a typical radius of 0.094 inch. Reference numeral  141  represents a ⅛ inch wide ground pressure relief slot. Unless otherwise designated, the radii are 0.063 inch. The minimum tube wall thickness is 0.13 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by  12  threads are unified threads of the 2A type. 
     FIG. 13 is a side plan view of a 1 inch NPT connector according to an embodiment of the present invention and FIG. 14 is an end view of the connector taken along line  14 — 14  of FIG.  13 . The connector is preferably made of a 300 series stainless steel material. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for line  14 — 14 , and reference numerals  144  and  145 . Reference numeral  144  designates a slot having a 2.31 inch outer diameter and a 0.41 inch deep from the back side, and having a typical radius of 0.094 inch. Reference numeral  145  represents a ⅛ inch wide ground pressure relief slot. Unless otherwise designated, the radii are 0.063 inch. The minimum tube wall thickness is 0.15 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by 12 threads are unified threads of the 2A type. 
     FIG. 15 is a side view of an end cap used in an apparatus according to an embodiment of the present invention. FIG. 16 is an end view taken along line  16 — 16  of FIG.  15 . FIG. 17 is an end view taken along line  17 — 17  of FIG.  15 . The end cap is preferably made of a 300 series stainless steel material. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designations for lines  16 — 16  and  17 — 17 , and reference numerals  146  and  147 . Reference numeral  146  designates a bore having a diameter of 1.80 inches that is 0.25 inch deep. Reference numeral  147  represents a bore having a diameter of 0.745/0.750 inch that is 1.13 inches deep from the bottom of a 1.80 inch diameter bore. Unless otherwise designated, the radii are 0.063 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by 12 threads are unified threads of the 2A type. 
     FIG. 18 is a side plan view of a 1½ inch NPT connector used in an apparatus according to an embodiment of the present invention. FIG. 19 is an end view of the connector taken along line  19 — 19  of FIG.  18 . The connector is preferably made of a 300 series stainless steel material. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for line  19 — 19 , and reference numerals  150  and  151 . Reference numeral  150  designates a slot having a 2.31 inch outer diameter and a 0.41 inch deep from the back side, and having a typical radius of 0.094 inch. Reference numeral  151  represents a ⅛ inch wide ground pressure relief slot. Unless otherwise designated, the radii are 0.063 inch. The minimum tube wall thickness is 0.20 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by 12 threads are unified threads of the 2A type. 
     FIG. 20 is an end view of a filter used in an apparatus according to an embodiment of the present invention and FIG. 21 is a side view of the pleated filter of FIG.  20 . The filter is preferably rated for a flow rate of 30 cubic feet per minute (cfm). Reference numeral  160  designates a resin coated industrial strength paper media having a 10 micron pore size. Numeral  161  designates a black plastisol seal that exists at both ends of the filter. 
     FIG. 22 is a cut away side view of a tap body of an apparatus according to an embodiment of the present invention taken along line  22 — 22  of FIG. 23, and FIG. 23 is an end view taken along line  23 — 23  of FIG.  22 . The material of the tap body is preferably a 300 series stainless steel. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for lines  22 — 22  and  23 — 23 . Unless otherwise designated, the radii are 0.063 inch. The preferred minimum tube wall thickness is 0.20 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by 12 threads at both ends of the body are unified threads of the 2B type. Numbers followed by the designation “DP” are depth dimensions. 
     FIGS.  24 — 26  show various end views and a side phantom view of a tap body useful in an apparatus according to an embodiment of the present invention. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions. Unless otherwise designated, the radii are 0.063 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. 
     FIG. 27 is a plan view of a drill bit including a cutting bit without a pilot bit, shown in breakaway view, useful in an apparatus according to an embodiment of the present invention. FIG. 28 is an end view taken along line  28 — 28  of FIG.  27 . FIG. 29 is an end view taken along line  29 — 29  of FIG.  27 . All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for lines  28 — 28  and  29 — 29 , and reference numerals  170  and  171 . Reference numeral  170  designates a unibit carbide cutter having a ¾ inch diameter. Numeral  171  designates a flatly ground surface, three of which are equally spaced around the circumference of the shaft. The material of the bit is preferably a 1035 or 1045 grade steel. Unless otherwise shown, all radii are 0.06 inch. 
     FIG. 30 is a plan view of a drill bit including a cutting bit without a pilot bit, shown in breakaway view, useful in an apparatus according to an embodiment of the present invention. FIG. 31 is an end view taken along line  31 — 31  of FIG.  30 . FIG. 32 is an end view taken along line  32 — 32  of FIG.  30 . All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for lines  31 — 31  and  32 — 32 , and reference numerals  180  and  181 . Reference numeral  180  designates a unibit carbide cutter having a 1 and {fraction (7/16)} inch diameter. Numeral  181  designates a flatly ground surface, three of which are equally spaced around the circumference of the shaft. The material of the bit is preferably a 1035 or 1045 grade steel. Unless otherwise shown, all radii are 0.06 inch. 
     FIG. 33 is a side plan view of a ¾ inch connector used in an apparatus according to an embodiment of the present invention. FIG. 34 is an end view of the connector taken along line  34 — 34  of FIG.  33 . The connector is preferably made of a 300 series stainless steel material. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for line  34 — 34 , and reference numerals  184  and  185 . Reference numeral  184  designates a slot having a 2.31 inch outer diameter and a 0.41 inch deep from the back side, and having a typical radius of 0.094 inch. Reference numeral  185  represents a ⅛ inch wide ground pressure relief slot. Unless otherwise designated, the radii are 0.063 inch. The minimum tube wall thickness is 0.13 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by 12 threads are unified threads of the 2A type. 
     FIG. 35 is a side view of a 1 inch connector used in an apparatus according to an embodiment of the present invention, and FIG. 36 is an end view of the connector taken along line  36 — 36  of FIG.  35 . The connector is preferably made of a 300 series stainless steel material. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for line  36 — 36 , and reference numerals  186  and  187 . Reference numeral  186  designates a slot having a 2.31 inch outer diameter and a 0.41 inch deep from the back side, and having a typical radius of 0.094 inch. Reference numeral  187  represents a ⅛ inch wide ground pressure relief slot. Unless otherwise designated, the radii are 0.063 inch. The minimum tube wall thickness is 0.15 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by 12 threads are unified threads of the 2A type. 
     FIG. 37 is a side view of a 1½ inch connector used in an apparatus according to an embodiment of the present invention, and FIG. 38 is an end view of the connector taken along line  38 — 38  of FIG.  37 . The connector is preferably made of a 300 series stainless steel material. All dimensions shown are in inches with the exception of angles shown in degrees (°). The numerals shown are dimensions with the exception of the designation for line  38 — 38 , and reference numerals  188  and  189 . Reference numeral  188  designates a slot having a 2.31 inch outer diameter and a 0.41 inch deep from the back side, and having a typical radius of 0.094 inch. Reference numeral  189  represents a ⅛ inch wide ground pressure relief slot. Unless otherwise designated, the radii are 0.063 inch. The minimum tube wall thickness is 0.20 inch. The connector is an investment cast piece, solution annealed, machine threaded, and cast to have a gray glass bead finish. Numbers preceded by an “R” are radii. The 2 and ¾ inch by 12 threads are unified threads of the 2A type. 
     The tapping tool of the present invention provides flexibility, long-life, and reliable operation, with only minimal maintenance requirements. The tool preferably is made of a strong stainless steel body with interchangeable stainless steel and high speed tool steel components that can be changed in a matter of seconds. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present invention without departing from the spirit or scope of the present invention. Thus, it is intended that the present invention covers other modifications and variations of this invention within the scope of the appended claims and their equivalents.