Service line access system

Process and apparatus for plugging or plugging and servering gas service lines may be deployed from a building without requiring access to either the utility service main or main tee connections. The processes are intended to be undertaken while gas is being supplied to the service. The apparatus also allows service lines to be relined under these conditions without requiring direct access to either the utility service main or main tee connections.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention generally relates to gas service connections and 
methods of repairing the same. More particularly, the present invention 
relates to improved methods and equipment for inspecting, relining, 
disconnecting and/or reconnecting gas service lines and gas service 
connections. 
2. Brief Description of the Background Art 
It is commonly desirable to physically access gas service lines for a wide 
variety of reasons. One such reason results from the previous construction 
of service lines from iron or ferrous alloy pipe. The choice of pipe may 
previously have been for reasons of economy or requirements of strength, 
local statutes or zoning requirements. This is still true, even though 
some localities now permit service lines to be constructed from, for 
example, plastic piping and the like. However, older and therefore more 
common iron pipes have, in most areas, been used in service for extended 
lengths of time and so, are now found to be in accelerated states of 
decay. In most instances, stress faults and corrosion are found in these 
pipes to be in at least nascent states, if not actually advanced 
throughout the gas service. The service then requires some form of repair 
or replacement so as to effectively preclude the corrosive perforation of 
any part of the line, in order to best ensure the continued safety and 
welfare of the public. 
In addition, in order to plug or seal the gas service lines, access is 
required, for example, in order to discontinue service to delinquent 
customers or to those who may have temporarily or permanently converted to 
alternate forms of utility service. Access to service lines is also 
required in order to physically sever the service from the main in the 
event, for example, that the building or structure to which the service 
supplies gas is to be vacated, demolished or, of course, moved. 
In order to safely perform any maintenance, repairs or other work on 
service lines, it is obviously necessary to be able to shut off the supply 
of incoming gas so as to prevent any inadvertent leakage. Heretofore, it 
has generally been necessary to dig about and isolate the gas main at the 
area in which it is connected to the service line. The connection between 
the main and the service is known as a "tee", and nearly always includes a 
shut-off valve. After the tee is closed, the service line may then be 
accessed or breached and worked on as may be necessary. 
It is known to those acquainted with this art that the above-described 
isolation procedure is an extremely expensive undertaking in nearly all 
aspects. Initially, local municipalities require construction permits for 
excavation. These permits often cost up to about $200.00 or more, each. 
Additionally, gas mains are usually located approximately six feet below 
ground level and often run both parallel to and beneath existing roadways. 
Since these gas mains have been laid under roadway surfaces, asphalt, 
brick, concrete and the like must be removed in order to isolate the 
service tee. Further, since these gas mains have often been installed in 
early communities in early 1900s, and sometime even in the previous 
century, precise and exact knowledge of their where to best dig for the 
gas main itself is often a matter of guesswork, let alone the decision of 
where along the main to locate the service line tee. Accordingly, these 
procedures are not jobs to be taken lightly, especially in cold, hot or 
even mildly inclement weather and certainly not be attempted at all in 
sub-zero temperature conditions. 
Although not affecting either the physical condition of the service line or 
the gas main, it is also necessary to shut off the gas flow when replacing 
a defective gas flow meter or removing one for service. This can, however, 
generally be accomplished from inside the gas-supplied structure without 
disrupting any of the service line, the roadway or the surrounding 
neighborhood. However, interrupting the service for such a temporary event 
does result in significant repercussions in that the gas lines within the 
structure must now be bled of atmospheric air and, of course, each service 
pilot which is fed off those lines must then be relit. The bleeding 
procedure often cannot be properly accomplished in one visit within any 
reasonable length of time and so multiple repeated service calls are 
required. This unavoidably results in both unnecessary consumer 
aggravation and increased utility expense. Thus, the various requirements 
of diverting commercial traffic, providing alternate access for local 
traffic and the expense of restoring the roadway surface to at least its 
former state, as well as the necessity of repeatedly rescheduling the 
return of work crews to previous job sites in order to correct earlier 
work has provided the impetus for the present invention. 
SUMMARY OF THE INVENTION 
The present invention provides an apparatus and a process for working on a 
service line irrespective of either climate or weather conditions. 
The present invention provides an apparatus and a process for shutting off 
gas flow to the service line without requiring direct access to the gas 
main. 
The present invention provides an apparatus and a process for renewing a 
defective service line without removing or displacing that service line. 
The present invention provides an apparatus and a process for shutting off 
gas flow to a service line and then physically disconnecting segments of 
that line without direct access to either the gas main or the service 
line. 
The present invention provides an apparatus and a process for restoring gas 
flow to disconnected service lines without direct access to either the gas 
main or the service line. 
The present invention provides an apparatus and a process which permits the 
replacement or servicing of a gas meter without disrupting the constant 
supply of gas to appliance and equipment standing pilots. The present 
invention provides an apparatus and a process for physically reconnecting 
previously disconnected service line segments without direct access to 
either the gas main or the service line. 
Accordingly, these features and others are provided by the present 
invention which is used while gas is free flowing from the underground 
main without, however, letting gas escape. The present invention utilizes 
a first valved gas lock device, one end of which sealingly engages a house 
tee and the other end of which sealingly engages various useful tools. A 
tee plug tool allows the removal of a house tee plug. The service line is 
inspected using an in-line camera to determine if the service and the main 
tee are in an appropriate condition for restoration. 
If the service and main tee are in an acceptable condition, a stopper 
insertion tool is then used to insert a stopper within the gas service so 
that the first gas lock may itself then be removed. The gas supply meter 
house service is disconnected from the house tee and the house tee is 
removed from the service. 
A second valved gas lock is then utilized which sealingly engages the 
plugged service line. The stopper tool is installed on this second gas 
lock and the stopper insertion tool is then used to remove the installed 
stopper from the gas service. The stopper tool is then removed from the 
gas lock. 
An auger is then used to clear the service of any excessive debris and the 
service is deburred of any significant internal protrusions or pipe edges. 
The bonding site is then finely reamed in order to receive an internal 
sealing plug. Finally, the service and bond site are repeatedly brushed 
and all loosened material is removed from the service. 
The service line is preheated at the cleared bonding site so that it will 
readily and permanently accept the plug. The plug is then inserted into 
the service either to the location of a service-perforating corrosion or 
up to the main tee, and the plug is heated. Heating the plug both releases 
the plug material and the coiled expansion springs within its construction 
in addition to activating a sealing adhesive which surrounds it, thus to 
seal the service from the main. 
An internal pipe cutter is then inserted into the service line and the 
service line is severed downstream of the bonded plug when a building or 
structure is to be demolished or moved. Otherwise, a hole saw is inserted 
through the service into the sealing plug in order to pierce a hole in the 
nose of the plug so as to reestablish gas flow to the disconnected or now 
repaired service line. 
In view of these procedures, the present invention is not, of course, 
employed if the service line condition at the bond site is extremely poor 
or if the main tee is itself leaking. Additionally, it may prove difficult 
to utilize the present invention if the service line is acutely angled, if 
the gas lines utilize curb valves or if there is insufficient work space 
within the house or structure. In these instances, prior art excavation 
techniques must be utilized.

DETAILED DESCRIPTION OF THE INVENTION 
As is illustrated in FIG. 1, a gas main 2 runs parallel to and beneath 
roadway 4. Service line 6 extends from main 2 via main tee 8 in twenty 
foot sections. Multiple sections of service 6 are joined together with 
threaded couplings 34. Main tee 8 is removably sealed to main 2 by threads 
10, although main tee 8 may be sealed to main 2 by any suitable removable 
or permanent means and is conventionally closed by valve 12. When open, 
valve 12 provides a gas connection from the interior of main 2 to service 
6. 
Service 6 desirably runs coplaner with and perpendicularly from main 2 
towards the foundation wall 14 of a structure. Service 6 is commonly 
designated a `1-1/4" pipe` and extends through wall 14 into basement 16 to 
terminate at house tee 18, located up to 100 feet or more from main tee 8. 
Those skilled in the art will understand that the 1-1/4" service 6 pipe 
actually has a 1-3/8" inside diameter. House tee 18 is provided with a 
removable tee plug 20 which is threadingly inserted into house tee 18. 
House tee 18 is also connected to house service line 22, which leads into 
meter 24 and then to secondary house service line 26. Since house tee 18 
is not provided with a cut-off valve, service 6 is always connected to 
provide gas flow to house service 22. House service 22 may be, however, 
disconnected from meter 24 via house valve 28. 
Therefore, in order to shut off valve 12 and preclude gas flow to secondary 
service 26, for example, in case of customer delinquency, it is clear that 
house valve 28 may not effectively be used, since valve 28 is readily 
accessible to the delinquent customer. Additionally, since valve 28 is 
downstream of service 6, in the event that service 6 is damaged by, for 
instance, perforating corrosion 32, valve 28 cannot stop gas flow for 
repair of any damaged sections of service 6. Therefore, in practice, it 
has been necessary to first excavate access hole 30 in order to locate 
main tee 8. Unfortunately, since service 6 does not always run 
perpendicularly to main 2, merely locating main 2 in front of house tee 18 
does not automatically locate main tee 8. Accordingly, main tee 8 is often 
located by first digging and then extending hole 30 along the length of 
main 2 until main tee 8 is discovered. Main tee 8 may then be shut off, 
discontinuing utility service. 
The present invention allows, for example, perforating corrosion 32 to be 
repaired without requiring access to valve 12. Access to valve 12 is not 
even required in the event that service 6 is to be plugged and radially 
severed from main 2. The present invention, therefore, enables the repair 
or plugging of service 6 even while line 2 continues to supply service 6 
with gas. This is known as procedures as in U.S. Pat. Nos. 4,394,202, 
issued July 19, 1983, 4,410,391, issued Oct. 18, 1983, and 4,487,432, 
issued Dec. 11, 1984. The present invention will be first illustrated in 
the context of plugging a section of corroded ferrous service 6 and then 
severing the service from main 2. 
The plugging procedure begins by entering basement 16 to gain access to 
house tee 18. Tee plug 20 is repeatedly struck with sufficient light blows 
using a hammer or other suitable object in order to dislodge any paint or 
corrosion which might otherwise seal tee plug 20 to house tee 18. 
Preferably, any such paint and corrosion are removed from tee plug 20 
using, if necessary, a wire brush. As much paint and corrosion as is 
practicable is also removed from house tee 18. House tee 18 and tee plug 
20 are both then cleaned up by generally removing loose debris. A device 
known as a gas lock 36 (best seen in FIG. 2) is then applied to the 
now-cleaned house tee 18. 
Gas lock 36 integrally consists of the following three general sections: 
tee clamp 38, ball valve 40 and seal assembly adapter 42. Clamp 38 allows 
gas lock 36 to be removably sealed to house tee 18 even without removing 
tee plug 20. Valve 40 enables gas lock 36 to selectively define a 
throughgoing gas passage from clamp end 44 to adapter end 46. The gas 
passage should maintain a clear bore of at least about 1-1/2 inches so as 
to best enable tee plug 20 removal and so as to provide ample clearance 
for other materials, tools and procedures which will be described below. 
Suitable ball valves 40 are commercially available from Asahi/America 
Corp., Medford, Mass. 02155. Adapter 42 enables a variety of secondary 
tools to be sealingly adapted to gas lock 36. Adapter 42 is one-half of a 
"quik" cam lever coupling which is sold under the Banjo tradename by 
Terra-Products, Inc., Crawfordsville, IN 47933. The other half of the cam 
lever coupling is seal jacket 54 and is illustrated, for instance, in FIG. 
3 and will be described hereinafter. 
Gas lock 36 is first abutted against house tee 18 such that clamp end 44 
engages and surrounds tee plug 20. As best seen in FIG. 2A, tee clamp 38 
features tee sealing gasket 39 to sealingly abut house tee flange 41. Tee 
latch mechanism 48, best seen in FIGS. 2B-2G is then utilized to sealingly 
retain clamp end 44 against house tee flange 41. 
Tee latch mechanism 48 is provided by a pair of actuating arms 350 and a 
locking link 352. Locking link 352 is formed by clamp 354 and a pair of 
clamp arms 356. As illustrated, for example, in FIGS. 2D and 2E, clamp 354 
is fixedly attached to clamp arms 356. Although those skilled in the art 
will recognize that the geometry of latch mechanism 48 may be varied as 
desired, it is preferred that clamp arms 356 are fixed to clamp 354 at a 
downward angle of about 15.degree.. In other words, as shown in FIG. 2E, 
the underside of clamp arms 356 should define an angle of about 75.degree. 
to arms 354. 
Each of clamp arms 356 is provided with an aperture 358 for receiving a tie 
rod 360 which is secured thereinto by any suitable fastening means such as 
threaded screws, brazing, adhesives and the like. Tie rod 360 adds 
desirable rigidity to tee latch mechanism 48 and also serves to limit the 
travel of locking link 352 by abutting against the downward-facing surface 
of house tee 18 when clamp 354 is fully engaged. Similar apertures 362 are 
found within the handle portions 363 of actuating arms 350 so as to 
securely receive tie rod 364. Tie rod 364 requires that handle portions 
363 are always parallel and thus ensures that actuating arms 350 are 
always displaced in equal amounts. Therefore, clamp 354 cannot be actuated 
in a crooked fashion, but rather, is always engaged perpendicularly. 
Ideally, the geometry of these various pieces is selected such that tie 
rod 364 abuts the underside of gas lock 36 at the same time that tie rod 
364 abuts the underside of house tee 18. This, of course, depends in part 
upon both the angle defined by actuating leg 366 of actuating arm 350 and 
the dimension of gas lock 36. However, it is preferred that actuating leg 
366 be offset from actuating arm 350 by 45.degree. , as shown in FIG. 2F. 
Moreover, as seen in FIG. 2G, actuating arm 350 features an offset portion 
368 to ensure that handle portions 363 clear any protrusions 370 of gas 
lock 36. In a similar manner, clamp arms 356 are affixed to clamp 354 in 
an outwardly spreading manner (see FIGS. 2C and 2D) so that clamp arms 356 
may easily be assembled to actuating legs 366. 
As best seen in FIGS. 2B and 2F, actuating lets 366 provide apertures 372 
adjacent to handles 363. Additional apertures 374 are provided at the ends 
of clamp arms 356. Thus, a conventional bearing 376 such as nylon or 
polytetrafluoroethylene washers and the like may be placed between clamp 
links 356 and actuating lets 366 concentrically around both apertures 372 
and 374 so that suitable retaining means 378 such as screws or rivets may 
be used to pivotably fasten actuating link 350 to clamp link 356. 
Similarly, actuating lets 366 also provide pivot apertures 382 which are 
adapted to align with pivot brace apertures 382 located in pivot braces 
390 which rigidly protrude from clamp end 44 (see FIGS. 2A and 2C). Thus, 
by inserting bearing 376 concentrically between pivot apertures 380 and 
pivot brace apertures 382, retaining means 378 may also be used to 
pivotably fasten actuating arm 350 to pivot brace 390. Thus, it will 
readily be appreciated that by raising the handles 363 of actuating arms 
350 until tie rods 360 and 364 abut house tee 18 and gas lock 36, 
respectively, clamp 354 may be withdrawn axially in the proximal direction 
against the distal flange 392 of house tee 18. 
However, since various house tees 18 are currently or have previously been 
commercially available which differ in length from distal flange 392 to 
proximal house tee flange 41, clamp 354 is also provided with depth 
adjusters 394. Depth adjusters 394 are formed by threaded apertures 396 
which are adapted to accept threaded adjusters 398. Threaded adjusters 398 
may then be adjusted so as to abut distal flange 392 and to ensure that 
gas lock 36 abuts house tee 18 with sufficient longitudinal force so as to 
seal flange 41 against sealing gasket 39. Desirably, set screws 400 are 
also provided and can be utilized so as to fix the proper adjustment of 
threaded adjusters 398. Further longitudinal adjustment is possible by 
providing that the channel which retains gasket 39 (see FIG. 2A) is, for 
example, 1/4" wide. Thus, the channel can accept conventional gaskets of 
1/8, 3/16 and 1/4" thicknesses, and affords gas lock 36 with even greater 
adaptability thereby. 
Referring now to FIG. 3, tee plug tool 52 is used to remove tee plug 20. 
Seal jacket 54 of tee plug tool 52 envelops and engages seal assembly 56 
of adapter 42. Clamps 58 are extended towards gas lock 36 in order for tee 
plug tool 52 to seal against adapter 42. One preferred such mechanism for 
engagement uses annular retaining channel 57 defined within seal assembly 
56. As best seen in FIG. 3A, seal jacket 54 slidably engages adapter end 
46 until seal assembly 56 abuts gasket 59. Manually extending clamps 58 
then enables cam means (unillustrated) to protrude inwardly into retaining 
channel 57. The cam means ensure that seal assembly 56 is biased against 
gasket 59 so as to gas seal tee plug tool 52 to seal assembly 56. Other 
suitable releasable engaging and sealing devices can, of course, be 
utilized. 
Tee plug tool 52 provides a rotatable and longitudinally reciprocable 
throughgoing shaft 60 having a handle and a square-ended proximal shaft 
end 64, as shown, and square-ended distal end. The distal end provides an 
internally threaded blind (e.g., not throughgoing) bore 74. Threaded bore 
74 is preferably tapered such that it defines a frusto-conical aperture in 
which the widest portion is most distal, as will be explained later. As 
provided, the distal end is thus adapted to engage either a conventional 
3/8" or 1/2" drive socket 62 with an imbedded magnet therein, which is in 
turn adapted to engage tee plug 20. For security. shaft 60 is also fitted 
with collar 63 so that shaft 60 may not accidentally be withdrawn from tee 
plug tool 52. Similarly, set screw 65 ensures that socket 62 cannot 
accidentally be removed from shaft 60. A conventional internal seal 
(unillustrated) provides a sealing interaction between shaft 60 and tee 
plug tool 52. Accordingly, when shaft 60 is within tool 52 which is fitted 
onto seal assembly adapter 42, gas cannot escape from service 6 even if 
valve 40 is opened. Thus, after tee plug tool 52 is attached to gas lock 
36, the assembled pieces define an air-tight apparatus and valve 40 may be 
opened so as to allow access to house tee 18 via adapter end 46. 
Shaft 60 is then slid towards tee plug 20 and rotated by hand until tee 
plug 20 is engaged, whereupon shaft 60 is rotated counter-clockwise using 
a "T" bar handle, ratchet, wrench or other suitable drive means on 
square-ended proximal shaft end 64 in order to remove tee plug 20 from 
house tee 18. Shaft 60 is then slid back (to the right, as viewed in FIG. 
3) so as to withdraw socket 62 to remove tee plug 20 to within seal jacket 
54. Magnetic socket 62 may be further assisted in retaining tee plug 20 by 
placing a small binding amount of putty seal inside socket 62 before 
engaging tee plug 20. Once plug 20 is within seal jacket 54, valve 40 is 
closed, clamps 58 are opened and tee plug tool 52 is removed from gas lock 
36 along with tee plug 20. Thus, tee plug 20 has been removed from house 
tee 18 in the preferred hot tap condition without the release of gas. 
It is now desirable to examine the inside of service 6 in order to 
determine if service 6 or main tee 8 is so badly deteriorated as to 
preclude restoration, as well as to locate any fault within service 6. To 
that end, the next step utilizes an internal pipe inspection camera 102, 
illustrated in Fig. 6. Camera 102 is electronically connected to power 
controller and a viewing monitor (both unillustrated). The power 
controller and video monitor are also desirably connected to a 
videocassette recorder so that work crews may then record the condition of 
service 6. 
The proximal end 118 of camera 102 is attachable to a flexible cable 
conduit or "feed snake" 120, best seen in FIGS. 7 and 8. A desirable 
conduit 120 is commercially available from the Teleflex Corp. Conduit 120 
features a jacket 122 formed of a flexible, resilient rubberized or 
polymeric material such as polyethylene within which may be laid either a 
resilient flexible polymeric or spiraled steel annular liner 124. Since 
the outer diameter of liner 124 is smaller than the inner diameter of 
jacket 122, an annular channel 126 extends longitudinally throughout 
conduit 120. Reinforcing wires 128 are frictionally retained and are 
oriented longitudinally within annular channel 126. Thus, conduit 120 is a 
flexible assembly which is substantially rigid axially and which defines a 
throughgoing aperture 130. Conduit 120 is efficiently coiled and carried 
on any suitable conduit reel such as that disclosed, for example, in U.S. 
Pat. No. 4,602,752, issued July 29, 1986. 
Conduit aperture 130 may be used to house a variety of elements to 
functionally connect various tools. For instance, in the case of camera 
102, a conduit 120 is selected which contains a plurality of electrical 
wires in order to provide power to camera 102 and transmit images 
therefrom. Other examples of connecting elements will, of course, be 
described later. 
Camera 102 is provided by a thin longitudinally oriented camera housing 104 
which may feature a flexible joint 106 at an intermediate point. Joint 106 
better enables camera 102 to traverse minor bends, jogs and angles within 
service 6. For optimal maneuverability, housing 104 is preferably about 
one inch or less in diameter and also, is preferably about ten inches 
long. One such camera is manufactured by the Fairchild Camera and 
Instrument Corp., Syosset, NY 11791. 
Camera 102 also provides a plurality of axially compressible guide rails 
108. Guide rails 108 are preferably tensioned at each end and the middle 
thereof by clamps 110. Preferably, the middle and distal clamps 110 
"float", e.g.., are not rigidly affixed to camera 102 but, rather, are 
movable longitudinally thereon. In contrast, however, it is advantageous 
if the most proximal clamp 110 only is rigidly affixed to camera 102. 
Guide rails 108 may be formed, for instance, of spring steel and desirably 
define a maximum outer radius which is at least about 3/4 of the inner 
diameter of service 6. Guide rails 108 function to locate camera 102 
substantially at or about the longitudinal axis of service 6. 
Additionally, since guide rails 108 are compressible, they do not preclude 
camera 102 from passing through most internal obstructions as well as the 
aforementioned bends, jogs and angles within service 6. 
At the front or distal end of camera 102, of course, is located lens 112. A 
guard 114 is formed of a bent rigid material, preferably metal, so as to 
best protect lens 112. Guard 114 is not so thick as to disrupt image 
viewing, but should still provide adequate protection against damage from 
ramming lens 112 into solid debris and guide camera 102 around obstacles. 
Guard 114 freely supports a circular member 116 which will, of course, 
always hang downwardly and thereby provides a simple maintenance-free 
indicia of orientation for camera 102. It is noted that the camera 
described herein is usable within service 6 even after a plastic insert 
pipe has been installed therein. 
A conduit gas lock adapter 132 is provided and is best seen in FIG. 9. 
Conduit gas lock adapter 132, in a manner substantially analogous to tee 
plug tool 52, envelopes and engages seal assembly 56 of gas lock 88. 
Clamps 134 are extended towards gas lock 88 in order for adapter 132 to 
engage assembly 56. Additionally, an internal seal 500, best seen in FIGS. 
9A-9C, fits within gas lock adapter and provides a sealing interaction 
between the outer surface of conduit 120 and conduit gas lock adapter 132 
while yet enabling conduit 120 to be both rotated and longitudinally 
reciprocated. 
Those skilled in the art will understand that conduit 120 is not inserted 
into an assembled internal seal 500 (since the gas tight interference fit 
therebetween would not allow such insertion). Rather, internal seal 500 is 
assembled around conduit 120. Thus, it will readily be appreciated that 
each of the different conduits 120 utilized in these procedures are 
desirably pre-equipped with their "own" gas lock adapters 132. 
Internal seal 500 is generally provided by an assembly of six different 
parts, e.g., holder 502, large collar clamp 504, small collar clamp 506, 
split clamp 508, O-ring 510 and two split seals 512. To assemble internal 
seal 500, two seals 512, best seen in FIGS. 9B and 9C are inserted over 
the distal end of conduit 120. Seal 512 is desirably a Poly-Pak part No. 
25000562 which is commercially available from the parker Corp. However, 
since such seals 512 are provided with a press-fit internal seal O-ring 
514, it is first necessary to remove O-ring 514 and make a single radial 
slit "a" (see FIG. 9B) before seals 512 may be slid onto conduit 120. 
After seals 512 have been installed upon conduit 120, conduit O-ring 510 
is also slid onto conduit 12. Conduit O-ring. 510 is also commercially 
available and is preferably part No. K50 of the Miller Production Co. 
Next, holder 502 is slid onto conduit 120 until it envelops each of 
conduit O-ring 510 and seals 512, as shown in FIG. 9A. Holder 502 is 
provided with a smooth internal sealing portion 514. Sealing portion 514 
does not, in fact, seal against conduit 12, but is used to orient the 
conduit 120-sealing members, e.g., O-ring 510 and seals 512 within holder 
502. Conduit O-ring 510 need not be split, of course, since the 
elastomeric construction thereof enables O-ring 510 to be stretched so as 
to pass over any minor obstructions at the end of conduit 120. 
Both halves of split clamp 508 are now installed over conduit 120 adjacent 
conduit O-ring 510. Split clamp 508 is simply a thick spacer-washer which 
is completely split once through its diameter. The inside diameter of 
split clamp 508 is preferably the same or only slightly larger that of 
either O-ring 51 or seals 512. Next, small collar clamp 506 and large 
collar clamp 504 are also installed over conduit 120. Each of the collar 
clamps 506, 504 are also completely split once diametrically. Large collar 
clamp 504 features four throughgoing apertures 514 and counterbores 516 
spaced at 90.degree. rotation, starting 45.degree. from the severed 
diameter. Apertures 514 and counterbores 516 in large collar clamp 504 are 
adapted to receive bolts 518 and align with bores 520 within holder 502. 
Bolts 518, when installed in large collar clamp 504 and holder 22, then 
enter threaded holes 522 within small collar clamp 506. If desired, of 
course, safety nuts 524 may also be used even though holes 522 are tapped. 
It is preferable that large collar clamp 504 and split clamp 508 are 
oriented such that their split diameters are offset by 90.degree. 
Additionally, each collar clamp 504, 506 may simply be attached by screws 
threaded into tapped bores within holder 502. Other conventional ways of 
fastening internal seal 500 may, of course, be utilized. 
Thus, it is seen that by tightening bolts 518, split clamp 508 and small 
collar clamp 506 will longitudinally compress conduit O-ring 510 and seals 
512 such that their inner diameters will shrink and axially press against 
conduit 120. Preferably, the longitudinal length of sealing portion 514 
and the thickness of split spacer-ring 508 are selected such that when 
large collar clamp 504 and small collar clamp 506 are fully tightened, 
O-ring 510 and seals 512 provide a gas seal against conduit 512. Finally, 
it will be appreciated that both of the collar clamps 504, 506 provide 
inwardly-oriented smooth chamfer surfaces 526. Chamfer surfaces 526 guide 
conduit 120 within internal seal 500 in both directions and preclude 
abrasive harm to conduit jacket 122. Thus, it is preferred that the 
smallest internal diameter defined by chamfer 526 is no larger than at 
least one of the internal diameter defined by conduit O-ring 510 or seals 
512 when internal seal 500 is fully assembled. 
A conventional seal (unillustrated) between the elements within aperture 
130 and liner 124 at the distal end 138 of conduit 120 prevents gas flow 
through aperture 130. Accordingly, when conduit 120 is installed within 
conduit gas lock adapter 132, and conduit gas lock adapter 132 is fitted 
onto seal assembly 56, gas cannot escape from service 6 even if valve 40 
is opened. 
When conduit 120 is inserted within conduit gas lock adapter 132, distal 
end 138 is provided with connector means 140 so as physically to connect a 
tool or instrument, such as camera 102 to the element within aperture 130. 
In this instance, camera 102 is used to determine the general condition of 
the main tee, the interior of service 6, the location..if any 
deterioration therein and its physical orientation. Since it is essential 
for either plugging or any service repair operations that service 6 be 
clean at any ultimate bond sites, it is also desirable that this 
inspection step be undertaken at both the beginning and completion of the 
entire operative procedure. 
Since the distance from valve 90 to seal assembly 92 may be less than that 
required to install conduit adapter 132 with camera 102 therein, an 
adapter extender 142, best seen in FIG. 10 may be installed 
thereinbetween. Extender 142 is provided by a seal Jacket assembly 144 and 
clamps 146. The seal jacket assembly 144 is integrally attached, via tube 
148, to a seal assembly 150. Tube 148 is metal, preferably aluminum, so 
that it can withstand high heat conditions as will be made clear 
hereinafter. Extender 142 is installed by first abutting jacket assembly 
144 against seal assembly 92 and then engaging clamps 146. Jacket assembly 
136 is then abutted against seal assembly 150 and clamps 134 are engaged. 
Valve 90 may then be opened and camera 102 inserted into service 6. In 
this regard, referring to FIG. 9, the exact distance which conduit 120 is 
inserted into service 6 may be measured by distance meter 152. One 
suitable distance meter 152 is sold by Kabelmat, Inc., Plymouth, MN., as 
Model No. M-10. Distance meter 152 is provided with drag wheel 154 and 
meter index 156. Before the initial step and each following step, meter 
index 156 is reset (or "zeroed") which ensures that, once a particular 
fault 32 within service 6 has been located, the selected cure may be 
precisely applied thereat. 
The next step relates to the removal of house tee 18 from service line 6. 
House tee 18 must be removed from service 6, in part, to facilitate the 
withdrawal of debris from inside service 6 which the physical constants of 
house tee 18 would not otherwise allow. The process uses a mulcare plug 
82, as illustrated in FIG. 4 and a "mulcare plug tool" 66 which is 
identical to tee plug tool 52 except for deleting magnetic socket 62 and 
providing a mulcare stopper 76 therefor. Mulcare stoppers are commercially 
available from the Mulcare Corp. Threaded end 74 threadingly and 
reversibly engages mulcare stopper 76. Preferably, threaded end 74 
provides a left-handed internal thread. Stopper 76 is provided by a 
stopper shaft 78 upon which a plurality of elastomeric discs 8 are spaced 
longitudinally apart. Discs 80 are both sized and spaced so as to 
frictionally engage and seal the inner aperture of service 6 against the 
flow of gas when stopper 76 is longitudinally inserted therein. Thus, in 
order to assemble mulcare plug tool 66 for use, magnetic socket 62 is 
removed from insertion tool 60 and stopper shaft end 82 is threadingly 
engaged onto threaded end 74. Assembled mulcare plug tool 66 is then 
abutted against seal assembly 56 of gas lock 36. Clamps 86 are extended 
towards gas lock 36 in order for gas lock 36 to sealingly engage adapter 
42. Valve 40 is opened and mulcare stopper 76 inserted through valve 40, 
house tee 18 and into service 6. Handle 72 of insertion tool 68 is then 
rotated clockwise so as to unthread and release mulcare stopper 7. Discs 
80 ensure that stopper 76 is frictionally retained within service 6 so 
that it does not rotate with handle 72. House valve 28 is then shut off so 
that gas does not escape from the gas-filled house lines and, of course, 
so that air does not enter such lines. Clamps 86 are then released so that 
plug tool 66 can be removed from gas lock 36. Handles 363 are then 
released, allowing clamp 354 to be loosened. Gas lock 36 is removed from 
house tee 18, allowing house service 22 to be disconnected from house tee 
18 and house tee 18 to be removed from service 6 in the conventional 
manner, leaving mulcare stopper 76 in place sealing the proximal end of 
service 6. 
The removal of house tee 18 allows the installation of a primary gas lock 
88, best seen in FIG. 5. Primary gas lock 88 is analogous to gas lock 36 
since it includes a valve 9 and seal assembly adapter 92. However, since 
primary gas lock 88 is adapted to attach directly to service 6 only when 
house tee 18 is removed, it provides an engaging coupler 94 which is 
internally threaded so as to reversibly and sealingly engage the 
externally threaded open end of service 6. Engaging coupler 94 may also 
feature an internal nylon or elastomeric sealing O-ring or gasket 
(unillustrated). Extending downward from primary coupler 94, and in gas 
communication therewith, is dirt leg 96 which may be selectively sealed by 
port valve 98. Dirt leg 96 may also, of course, be located between valve 
90 and adapter 92, if desired. However, since debris within service 6 will 
be evacuated via dirt leg port 100, it is desirable that dirt leg 96 is 
located between service 6 and valve 90. Such location ensures that debris 
is not passed through gas lock 88 where it might otherwise affect the 
function of valve 9. 
After primary as lock 88 is installed on service 6, it is initially 
required to remove mulcare stopper 76 from within service 6. In this 
regard, mulcare plug tool 66 is first abutted against seal assembly 
adapter 92. Since adapter 92 is functionally identical to seal assembly 
adapter 42, clamps 86 also function to secure mulcare plug tool 66 to 
primary gas lock 88. Valve 9 is then opened to enable mulcare stopper tool 
68 to be inserted through primary coupler 94 and into service 6 until it 
abuts mulcare shaft end 82. Since the procedure thus far is "blind", it is 
easier for the technician to align and thread stopper tool 68 around 
stopper shaft 82 because the previously described frusto-conical threaded 
bore 74 helps guide shaft 82 into stopper tool 68. Insertion tool handle 
72 is then rotated counter-clockwise so as to threadingly retain mulcare 
stopper 76 within shaft threaded end 74. Alternatively, it is possible to 
attach mulcare plug tool 66 to primary gas lock 88 and then threadingly 
engage bore 74 onto stopper shaft 82. Once shaft 82 has been so engaged, 
primary gas lock 88 can be engaged on seal assembly adapter 92 nd valve 90 
opened. 
The mulcare stopper tool 68 is then withdrawn, pulling mulcare stopper 76 
from service 6 into mulcare plug tool 66. Primary valve 90 is then closed, 
clamps 86 released and mulcare plug tool 66 is removed from primary gas 
lock 88. The next step requires that service 6, and especially, the bond 
adhesion site for the plug for service 6 be cleaned. The particular step 
which will be utilized, however, depends upon how congested with debris it 
appeared that the inside of service 6 was when service 6 was initially 
inspected with camera 102. Initially, however, no matter which step is 
required, a conduit 120 which provides a rotating flexible drive shaft 
(unillustrated) within aperture 130 will be installed within conduit 
adapter 132 and the drive shaft at the proximal end of conduit 120 will be 
connected to a conventional pneumatic motor. Pneumatic motors with a wide 
variety of performance characteristics may, of course, be chosen. However, 
a motor which is preferred will provide approximately 40 inch-pounds of 
torque at about 2000 rpm. It is desirable that the pneumatic motor can 
provide such torque during both clockwise and counter-clockwise operation. 
Such characteristics may, in fact, be provided by some of the larger 
commercially available hand-ated air drills. 
If the inside of service 6 is severely clogged with debris, and 
particularly if such debris is in the form of large chunks and 
particulates, auger 158 (best seen in FIG. 11) is installed on conduit 
1120. Auger 158 is formed of case-hardened cold-rolled steel and provides 
a right-hand thread screw 166 which is rotated in a clockwise direction. 
Therefore, when used to traverse the length of service 6, auger 158 will 
remove much of the dust, dirt, rust and coal tars therein. Auger 158 is 
provided by a shaft 160 having a threaded end 162 so as to releasably 
engage threaded connector 140. It is extremely preferable that after any 
tool, such as auger 158, is installed on connector 140, that it be more 
reliably secured thereto by set screw 164 (FIG. 9). Set screw 164 ensures 
that counter-rotation of the tool can occur either intentionally or 
accidentally without irretrievably losing such tool within service 6. 
If the proximal interior of service 6 is severely corroded or excessively 
blocked, it may be extremely difficult to feed the distal end 163 of auger 
158 thereinto. Thus, tap 650 (see FIG. 11A) may be installed onto distal 
end 163 of auger 158 and secured by set screw 652. Tap 650 is also formed 
of case-hardened cold-rolled steel and features the same thread direction 
as auger 158, so that it tends to feed auger 158 into service 6 while 
auger 6 looses and removes debris. In this instance, of course, it may not 
have been possible to previously have utilized camera 102. Accordingly, 
camera 102 may be first used only after this present step. 
Valve 90 may then be closed so that dirt trap 202 can be removed for 
emptying. Dirt trap 202, best seen in FIG. 15, is attached by threaded 
connection 204 to complementary threaded connection 206 provided on dirt 
leg port 100. Dirt trap consists of an elongated tube 208 which features 
threaded connection 204 at one end and threaded connection 210 at the 
other. Cap 212 is provided which is installable on threaded connection 210 
and may be removed in order to empty dirt trap 202. It is now estimated 
that up to about 80% of the debris within service 6 has been loosened and 
removed within dirt trap 202. 
At this stage, whether or not service 6 needed augering, reamer-deburrer 
654 (best seen in FIG. 11B) is now installed on a conventional universal 
joint (unillustrated). The universal joint is not required to traverse 
bends and the like within service 6. Rather, the universal joint is used 
because it creates more "slack" in the system, so that deburring may 
desirably exhibit a more violent motion when rotating than it otherwise 
might and therefore, deburr more effectively. Reamer-deburrer 654 is 
provided by a conventional 1-1/4" carbide tipped drill bit which has been 
modified to provide a threaded end 656. Reamer-deburrer 654 is used to 
traverse the length of service 6 only up to the distance of the pipe joint 
4 which inspection camera 102 had previously revealed. Reamer-deburrer 654 
quickly bores through and expands such joints 34, but is never inserted 
further into service 6, of course, since it could easily be used to 
inadvertently bore completely through main tee 8. 
Conduit adapter 132 is then reinstalled on extender 148 and valve 90 is 
opened. Conduit 120 is inserted until reamer-deburrer 654 clears valve 90 
and the pneumatic motor is then started. Conduit 120 is then reciprocated 
throughout service 6 at most to the depth which inspection camera 102 had 
previously attained. Reamer-deburrer 654 is intended to substantially 
remove excess pipe bead and smooth protruding pipe edges within service 6 
which result from, for example, careless pipe cutting when service 6 was 
originally laid. After reamer-deburrer 654 has sufficiently traversed 
service 6, the pneumatic motor is turned off and conduit 120 is withdrawn. 
It is preferable that reamer-deburrer 654 makes at least four complete 
reciprocations of service 6 over any burrs detected by inspection camera 
102. Once reamer-deburrer 654 has cleared valve 90, valve 90 is closed, 
clamps 134 are released and the conduit adapter 132 is removed from 
extender 142. Reamer-deburrer 654 is then removed from the universal 
joint. Reamer-deburrer 654 is then replaced on the universal joint with a 
tapered nylon bristle pipe sweeper brush 214, best seen in Fig. 16. Pipe 
sweeper brush 214 preferably has a diameter substantially equal to or 
slightly larger than the inside of service 6. A preferred maximum diameter 
may be selected, for example, within the range of from 1-5/8 to 1-7/16 
inch. Additionally, it is desirable that brush 214 not prevent a constant 
outside diameter. As pictured, the outside diameter of brush 214 is 
greatest near its middle, although brush 214 could also reach a maxima at 
either its distal or proximal end. As with auger 158, nylon brush 214 is 
preferably handed so as to provide a spiral which is the same as the 
direction of rotation as the pneumatic motor. In other words, if the motor 
is made to rotate clockwise, a nylon brush 214 should be selected which 
features a right-handed spiral so that loosened debris is withdrawn toward 
basement 16, and not pushed towards main 2. A preferred brush 214 may be 
provided by mounting 0.014 inch diter nylon bristles on a #8 double stem 
single spiral wire shaft. Thus, when brush 214 is rotating, loose debris 
is deposited toward dirt leg 96 and valve 98 into dirt trap 202. It should 
be noted that unlike the operation of reamer 188, nylon brush 214 is used 
throughout the length of service 6. Suitable brushes are commercially 
available from the Mill-Rose Co., Mentor, OH 44060. 
It is highly preferable that pipe sweeper brush 214 also be used after each 
of the following augering and deburring operations. Such extra usage, of 
course, cleans out service 6 before such deburring or reaming steps which 
desirably lessens the time which is otherwise necessary for such steps. 
Additionally, the less debris which is within service 6 tends to decrease 
the rate of wear of the various cutting edges on replaceable blade 
deburrer 170 and replaceable blade reamer 188. 
Replaceable blade deburrer 170 is now installed on universal joint and 
conduit 120. Deburrer 170 is formed of a solid billet 172 which defines a 
blade receiving opening 174. Adjacent blade receiving opening 174 are 
recesses 176 which are tapped to threadingly engage allen bolts 178. 
Billet top or "capping" section 180 defines apertures 180 accept allen 
bolts 178 which center blade 184 within opening 174. Top section 180 also 
cooperates with indent 183 in blade 184 and key 185 in receiving opening 
174 to effectively prevent blade 184 movement therein. The top sections of 
apertures 180 are wider so as to recess the tops of allen bolts 178 which, 
when tightened, compress billet top face 182 against blade 184 within 
blade receiving slot 174, such that blade edges 186 protrude from either 
side of billet 172. Deburrer 170 is utilized at least at the intended bond 
site. However, if desired, deburrer 170 may be utilized throughout service 
6. After the use of deburrer 170, nylon brush 214 is again used to remove 
debris from within service 6. 
Replaceable blade reamer 188, best seen in FIG. 14 is now installed on the 
universal joint. Replaceable blade reamer 188 is formed of a base 190 
which attaches to the universal joint and which provides a protruding 
retaining shaft (unillustrated). Reaming bits 192 longitudinally slide 
onto the retaining shaft but are not rotatable relative to base 190 since 
retaining shaft does not provide a round cross-section. Cap 194 is 
threaded so as releasably to engage the retaining shaft and retain reaming 
bits 192 thereon. Reaming bits 192 provide a substantially round outer 
cross-section having a rough coarse-knurled periphery 196. Located within 
periphery 196 are reaming channels 198. Reaming channels 198 provide edges 
200 which ream the inside of service 6 and provide an acceptably smooth, 
clean finish on the surfaces prepared by deburrer 17. Moreover, reaming 
channels 198 also act as flutes so as to remove debris from the reamed 
surface of service 6. In contrast to the preceding steps however, reamer 
188 is strictly used within service 6 only at the intended pipe plug 
bonding site. That is to say, reamer 188 need not used to repeatedly 
traverse the length of service 6. As before, after use, reamer 188 is 
removed from conduit 120 and replaced with nylon brush 214, which again 
removes any debris from service 6. 
Tapered nylon bristle pipe sweeper brush 214 is then replaced on the 
universal joint with a stainless steel site brush 216, best seen in FIG. 
17. At this point, service 6 should be nearly 95% or more free of any 
debris which was originally present. Like nylon sweeper brush 214, 
stainless steel brush 216 also preferably has a diameter substantially 
equal to or larger than the inside of service 6 and is used to remove rust 
oxides. In this regard, a preferred minimum diameter of steel brush 216 
is, for instance, 1-1/4 inch. Brush 216 is preferably formed of a 
conventional cylindrical shape with bristles of crimped-type 0.008-0.014" 
diameter 302 stainless steel mounted on #8 double stem single spiral wire. 
Such brushes are also commercially available from the Mill-Rose Co , 
Mentor, OH 44060. 
Unlike nylon brush 214, steel brush 216 is primarily intended to remove 
oxides only from the ultimate bond site of the plugging or repair 
operation, although brush 216 may be traversed throughout service 6, if 
desired. Also unlike nylon brush 214, steel brush 216 is preferably handed 
so as to provide a spiral which is opposite to the direction of rotation 
as the pneumatic motor. It has been found that about an additional 50% 
weight of rust oxides may be removed by providing stainless steel brush 
216 with the reverse handed spiral, than if the spiral were not so handed. 
Moreover, the minimal amount of such oxides which are cleared from the 
bond site are simply deposited in main 2. After the service 6 bonding site 
has been cleared of rust oxides, stainless steel brush 2I6 is then 
withdrawn past valve 90, valve 90 is closed, clamps 146 are released and 
conduit extender 142 is released from gas lock 88 along with conduit 
adapter 132. Service 6 is now ready to be either plugged or repaired, as 
desired. 
In order to seal service 6 from main 2, a plug 218, best seen in FIG. 18, 
must be annealed to the section of service 6 which has now been reamed, 
deburred, brushed and cleared of rust. A suitable plug 218 is taught, for 
example, within U.S. Pat. No. 4,295,494, issued Oct. 20, 1981. Briefly, 
however, such plug 218 should be self-expanding and thermally activated. 
Plug 218 may desirably define dimensions of about 1-1/8 inch external 
diameter and 10 inches overall length. The basic plug material may be of a 
plastic elastomeric formulation. 
Plug 218 is also overcoated with a hot melt adhesive 228 which provides 
excellent bonding, shear and pressure sealing capabilities. It is 
preferable that adhesive 228 be solid at room temperature and be a high 
strength material with hood bonding ability, provide cold flow and 
embrittlement resistance and resist the varied effects of natural gas, 
mercaptan odorant, ground water, bacteria, shock and vibration. A class of 
suitable ethylene copolymer resin adhesives are marketed by E.I. du Pont 
de Nemours and Company. O-rings 230 envelop the tube of plug 218 and 
provide sufficient damming surface area to retain additional adhesive 228. 
Square section O-rings 230 are preferred since they provide even more 
surface area than round O-rings and are less likely to roll off tube 22 
when plug 218 is inserted within service 6. 
Ideally, plug 218 expands to produce sealing contact both within service 6 
in addition to a short distance within main tee 8 in order to form a 
sealing ring of adhesive 228 around main tee 8 and the fitting threads 
thereof. 
In order to install plug 218 within service 6, service line cartridge 
preheater 232, best seen in FIG. 19, is attached to a conduit 120 which 
provides suitable Service preheater 232 is preferably up to about 1-1/4 
inch in diameter and five inches in length. These dimensions ensure that 
service preheater 232 can readily traverse the cleared internal bore 
passage of service 6, including any remaining debris, deposits or 
obstructions, bends, joints and the like. In this regard, service heater 
232 defines a rounded proximal end 234 and a rounded distal end 236 to 
preclude heater 232 from being hindered by any such obstructions. 
Moreover, it will be understood that the chosen dimensions of service 
preheater 232 automatically ensure that similarly-sized plug 218 will also 
be able to traverse service 6. 
Service line preheater 232 should quickly be able to raise the temperature 
of the inside of service 6 to about 300.degree.-325.degree. F. Ideally, 
such temperature should be attained within about 20 minutes or less. The 
service 6 plug bond site is preheated in order to ensure optimal wetting 
action and to prevent an otherwise unheated service 6 from "heat-sinking" 
when the plug 218 is itself later heated. Through the use of service line 
preheater 232, such heat sinking is actually precluded not only by raising 
the temperature of service 6, but as (or more) importantly, by also 
heating the ground and moisture surrounding service 6. Service line heater 
232 is removed from service 6 after the temperature of the bond site has 
been raised as desired and preferably, when such temperature has reached 
equilibrium. Service line preheater 232 is then replaced with plug heater 
238, best seen in FIG. 20. 
Plug heater 238 provides a heating element shaft 240 and a base area 242. 
Plug heater 238 provides a portion of longitudinal springs 244 as well as 
a plurality of concentrically tapered barbs 246. Springs 244 serve to keep 
plug heater 238, and therefore plug 218 centered within service 6, while 
barbs 246 mechanically engage the open end of plug 218 and prevent plug 
218 from inadvertently being pulled off plug heater 238. Ideally, base 
area 242 is sufficiently thick to preclude plug heater 238 from entering 
an excessive distance into plug tube 220. In this regard, shaft 240 is 
short enough to provide that distal tip 248 thereof does not touch closed 
end 222 of tube 220. Therefore, plug 218 is able to expand in diameter and 
also shrink in a longitudinal direction when heater 238 is activated 
without incurring any sort of binding interference from plug heater 238. 
Plug heater 238 is inserted into service 6 until plug 218 reaches the 
previously cleaned and preheated bonding site. As always, this location is 
precisely determined using distance meter 152, discussed previously. 
Electrical power is then provided to plug heater 238, which quickly 
reaches its operating temperature which is held for twenty minutes. 
Ideally, it should take no longer than 5-7 minutes to energize plug heater 
238 after preheater 232 is removed. By this time, the temperature of the 
inside pipe surface at the previously preheated bonding site will probably 
have dropped to approximately 150.degree.-160.degree. F. The particular 
temperature drop depends, of course, upon the length of time required to 
insert plug 218 within service 6, and also upon the ambient ground 
temperature and moisture content surrounding service 6. In any event, any 
preheating of the bonding site always decreases the "heat sink" effect of 
service 6 so that plug 218 may be installed more effectively. 
Additionally, the hot melt adhesive 228 should not contact a comparatively 
chilled bonding site surface, so that the hot melt adhesive 228 can better 
wet and adhere to the bonding site. 
Plug heater 238 remains energized for approximately twenty minutes after 
the inside temperature of service 6 reaches from 185.degree.-200.degree. 
F. Such temperatures ensure that hot melt adhesive 228 flows well, since 
it flows at approximately 175.degree. F. Such temperature is, of course, 
easily attained within the interior of service 6. Plug heater 238 is then 
removed from service 6 and electrical power to heater 238 is disconnected. 
Plug heater 238 is then withdrawn past valve 90 and valve 90 is closed. 
Conduit adapter 132 is removed from gas lock 88 and from 20-30. minutes 
(depending upon weather and ground conditions) are waited until plug 218 
and hot melt adhesive 228 have cooled. At this point, camera 102 is then 
reinstalled on conduit 120 and reinserted within service 6 to verify that 
plug 218 appears to be well fixed at the bond site. A plug 218 which is 
properly inserted by the previous procedure would ideally be able to 
provide a useful seal at a pressure of up to about 12 inches water column 
over a temperature range of from 0.degree.-140.degree. F. However, the 
effectiveness of the installation of plug 218 cannot be so tested. Rather, 
the permanence of the installation of plug 218 is tested by checking for a 
blow condition. Thus, an additional hour is waited for plug 218 and 
service 6 to completely cool so that the plug bond is thoroughly set. 
Pressure test adapter 250, best seen in FIG. 21, is then installed on gas 
lock 88. Pressure test adapter 250 is a seal jacket 54 (previously 
described) which has been capped and fitted with a gas tap 251. Soap water 
solution is applied to gas tap 251 and valve 90 is opened. If bubbles are 
formed at gas tap 251, it is clear that plug 218 is not properly installed 
and a second plug should, of course, be fitted downstream thereof. 
In the event that plug 218 has been installed in order to discontinue 
utility service to a delinquent customer, such operation has been 
completed. However, should the delinquency be paid up so that the gas 
supplier wishes to reinstate utility service, closed end 222 of installed 
plug 218 may be penetrated by a conventional mechanical penetrating 
device, such as a 7/8" hole saw 252, best seen in FIG. 22. Hole saw 262 
provides a mechanical penetrating device 264 and a plug cutter 266. Plug 
cutter 266 is formed by a sharpened cylindrical wall 268. Wall 268 defines 
an annular void 270 around penetrating device 264 and is attached to 
device 264 by plug 272. Hole saw 252 features coupon retaining section 271 
and is particularly preferred to other devices, since it both opens a 
large aperture and still captures the cut slug of plug 218. Thus, service 
6 is not littered with unnecessary plug debris. Penetrating device 264, of 
course, works in conjunction with the equipment described above. 
If utility service is to be discontinued for a prolonged length of time, 
many local statues require that service 6 be physically severed from main 
2. This requires that an internal pipe cutter (unillustrated) be installed 
on conduit 120. A suitable internal pipe cutter is disclosed, for example, 
in U.S. Pat. No. 4,369,573, issued Jan. 25, 1983. Preferred cutters are 
smaller than about 1-1/4 inch diameter and 18 inches overall length. 
Particularly preferred cutters also lock themselves into the radially 
expanded position for more efficient cutting operation. It is preferable 
that a conventional spring-loaded self-centering device be utilized 
adjacent the pipe cutter to keep such cutter oriented along the 
longitudinal axis of service 6. Similarly, it is desirable that a 
longitudinal fixing device also be utilized adjacent the pipe cutter. The 
longitudinal fixing device may be provided, for example, by a mulcare 
stopper 76 which is modified by piercing discs 80 so that stopper 76 may 
be inserted into service 6 without compressing the air therein. Stopper 76 
is also modified so that the pipe cutter may rotate without losing stopper 
76 within service 6. This may be attained, for example, by allowing discs 
80 to rotate on shaft 78 and by fixing threaded end 74 to the pipe cutter 
using a set screw arrangement. Therefore, the pipe cutter may be both 
laterally and longitudinally fixed within service 6. Preferably, the pipe 
cutter is located in between the centering device and the fixing device. 
Most preferably, the fixing device is located at the distal end of the 
pipe cutter. Many local ordinances and statutes require that abandoned 
services 6 be severed at two separate locations close to main 2. 
Accordingly, the internal pipe cutter may then be withdrawn a few inches 
and the cutting procedure may be repeated. Internal pipe camera 102 should 
then be employed in order to insure that the service 6 cuts are actually 
complete. 
It will now be explained that by altering the above-described operation, 
service 6 may be relined, i.e., entirely renewed. At this stage, of 
course, service 6 has been augered (if necessary) and deburred, and at 
least the bonding site has been reamed. Service 6 has also been swept 
clear of debris and the bond site is currently being preheated. 
A section of relining plastic pipe (unillustrated) is now inserted through 
a snorkel apparatus 254, best seen in FIG. 23. The plastic pipe is of any 
suitable material, preferably high density polyethylene resin. One 
suitable pipe features a 1-1/8" outside diameter and a 1" inside diameter 
and is known as Driscopipe 8000 and is commercially available from the 
Phillips Driscopipe Co., Richardson, TX 75083. Snorkel 254 provides a 
jacket assembly 256 with clamps 258 in order to engage seal assembly 
adapter 92. Snorkel 254 also provides an extendible, flexible support 260 
with a conventional gas seal 261 through which the relining pipe may be 
inserted. After the pipe is inserted through gas seal 261 into support 260 
so as to extend through jacket 256, such end is bonded to the open end of 
a short section of plastic pipe bonded to open end 220 of a plug 218, 
which assembly (unillustrated) is called a "pigtail". Pintails are not 
assembled in the field, of course, so that plug 218 cannot be accidentally 
activated while not yet inserted within service 6. The pipe may be bonded 
to plug 218 using any conventional connector, such as that disclosed 
within U.S. Pat. Nos. 4,657,287, issued Apr. 14, 1987 or 4,465,309, issued 
Aug. 14, 1984. Thus, after the pigtail is bonded to the plastic pipe, 
jacket assembly 256 is extended over plug 218, while the pigtail/plastic 
pipe connector is within the snorkel assembly, allowing gas seal 261 to 
seal around the plastic pipe. 
Service line preheater 232 is now removed from service 6, jacket assembly 
256 is abutted to seal assembly 92, and clamps 258 are engaged. The 
plastic pipe/plug 218 assembly is then inserted through service 6 until 
plug 218 reaches the preheated bond site. The plastic pipe is then cut off 
from its feed roll adjacent pipe seal 261. A plug heater 247 (best seen in 
FIG. 24) is fed through the relining pipe assembly until base area 249 
abuts upon plug 218, whereupon heater 238 is energized and plug 218 sealed 
to the bonding site. As noted in FIG. 24, plug heater 247 only provides a 
shortened plug heating area 251, so as to ensure that the area of plug 218 
which is bonded to the short section of pigtail pipe remains undisturbed. 
After waiting 20-30 minutes, plug 218 has then sufficiently cooled that 
camera 102 may be inserted within the plastic pipe to determine that plug 
218 is completely expanded and that the plastic pipe/plug 218 joint is 
intact. Jacket assembly 26 is then disengaged from seal assembly 92 and 
the service pipe is cut so as to protrude a predetermined distance from 
service 6. It is now necessary to test the service pipe insert to ensure 
that the plug 218 is adequately sealed to service 6. Therefore, a small 
amount of duct seal (John Mansville Corp.) is applied within the annular 
area defined by the plastic pipe end within service 6. A small hole is 
pierced through the duct seal and soap solution is applied. If no bubbles 
form, of course, plug 218 is properly installed. Similarly, duct seal may 
be similarly applied across the opening of the plastic pipe to ensure that 
plug 218 was not accidentally pierced by plug heater 247. 
A relining house tee (unillustrated) known as a Posilock basement tee, sold 
by the Inner-Tite Corp., Springfield, N.J. 07081, is installed upon the 
threaded end of service 6 within basement 16. Such relining house tee 
functionally differs from house tee 18 by providing an internal ledge or 
flange so as to engage and support the proximal end of the plastic 
relining pipe. This flanged support is commonly required by local code in 
many municipalities. House service 22 is then connected to the relining 
house tee and a third gas lock device (unillustrated) is installed on the 
relining house tee. The third gas lock differs from gas lock 36 only in 
being sized to specifically engage the dimensions of the relining house 
tee. 
Gas tap 250 is now installed on the third gas lock and the relined service 
6 tested to ensure that the installation of the relining house tee did not 
displace installed plug 218, by repeating the previously-described soap 
bubble test. After passing such test, in order to finish the installation 
of the plastic relining pipe, the sealed end 222 of plug 218 must be 
opened up to restore gas flow. This process utilizes hole saw 262 in the 
manner described previously. Valve 90 is then closed, clamps 146 are 
released and extender 142 is removed from gas lock 88. Tee plug 20 is then 
reinstalled. Finally, it will now be explained how the present invention 
may be utilized in order to replace gas meter 24 in a hot tap mode without 
discontinuing or interrupting gas flow to standing pilots. As illustrated 
schematically in FIG. 25, gas lock 36 has been used to remove tee plug 20 
from house tee 18 as described previously. Of course, if service 6 has 
previously been relined with plastic pipe, the third gas lock will have 
been installed on the relining house tee in a similar manner. 
A conventional drip let (unillustrated) will then be grasped with, for 
example, slip-lock pliers and loosened slightly, such that when the drip 
leg cap is turned, the drip leg will rotate in the drip leg tee 554, 
rather than the drip leg cap rotating on the drip leg. Of course, if tee 
554 merely has a tee plug (unillustrated), such plug need only be loosened 
in the previously described manner. 
Elastomeric seal 550 of drip leg valve: 552 is then placed over drip leg 
tee 554. Seal 550 is attached to both drip leg valve 552 and drip leg tee 
554 by any manner, desirably using hose clamps 556. Drip leg valve 552 
features both a conventional gas-tight sliding gate valve 558 and adapter 
42. Thus, by the use of a suitably modified tee plug tool 52, the loosened 
drip leg may easily be removed. Gate valve 558 is then closed and tee plug 
tool 52 is removed from drip leg valve 552. Preferably gate valve 558 
features a rotating handle, so that it may be conveniently operated 
without interference from the basement walls or pipes thereon. Air from 
within drip let valve 552 does not, of course, flow into secondary service 
26, since the gas supply is pressurized somewhat, whereas any air in drip 
let valve 552 is only at atmospheric pressure. Gas lock 36 is then 
connected to drip leg valve 552 by flexible 1" (inside diameter) gas 
transfer hose 560 and gas wand 564, best seen in FIG. 26. Gas wand 564 
consists of an outer wand 566 (FIG.. 27) and an inner wand 568 (FIG. 28) 
extending therein. Outer wand 566 is formed by a tube providing a 
throughgoing longitudinal bore 570. The proximal end 572 of outer wand 566 
features threads 574 and circumferential groove 576, which contains snap 
ring 578. The distal end 580 of outer wand 566 provides a threaded tapered 
end 586 and circumferential groove 582 which retains snap ring 584. 
Proximal of channel 582 are a plurality of axial bores 588 which provide a 
fluid connection from the exterior of outer wand 566 to bore 570. 
Inner wand 568 is provided by a throughgoing longitudinal bore 590. At the 
proximal end 592 of inner wand 568 is transfer tube 562, which itself 
provides a throughgoing longitudinal bore 594 which is fluidly connected 
to bore 590. Also located on wand 568 are circumferential grooves 596 and 
598. Grooves 596 are used to retain snap rings 600, and grooves 598 are 
used to retain O-ring seals 602. Snap rings 600 laterally retain threaded 
collar 604 on inner wand 568. Additionally, seals 602 provide a gas seal 
between inner wand 568 and outer wand 566, when wands 566, 568 are 
assembled. Elastomeric plug 606 is also fitted onto the distal end 608 of 
inner wand 568, when such wands 566, 568 are assembled, and is retained by 
lip 610. 
As shown in FIG. 26, outer wand 566 is inserted into a wand seal jacket 
612, which is analogous to previous seal jacket 54. Seal jacket 612, 
however, features plug seal 614 with internal O-rings 616 so as to provide 
a gas seal with outer wand 566. Snap ring 584 is thereby used to preclude 
outer wand 566 from being withdrawn from seal jacket 612. Similarly, plug 
606 precludes inner wand 568 from being withdrawn from outer wand 566. 
Finally, transfer tube 562 and seal jacket 612 provide conventional 
statically closed (compressed-air hose) snap fittings 618, 620, 
respectively. 
Now that gas lock 36 is connected to drip leg valve 552 by gas transfer 
hose 560 and gas wand 564, air within seal jacket 612, wand 564 and gas 
hose 650 must be evacuated. Therefore, a hose is attached to snap fitting 
618 and led outside of basement 16. Valve 40 is opened and backflow of gas 
from service 6 will evacuate air from gas lock 36, hose 560, bore 590 and 
seal jacket 612 through snap fitting 618. By inserting inner wand 568 into 
outer wand 566 (leftwardly, as viewed in FIG. 26), bores 588 move leftward 
of seals 616 into seal jacket 612. Thus, air within the annular chamber 
defined by inner wand 568 and bore 570 is also evacuated. Once a gas 
quality meter indicates that flow from snap fitting 618 is pure gas, the 
hose attached thereto is removed, automatically shutting off gas flow 
therefrom. 
Outer wand 566 is then inserted through gate valve 558 until threaded 
section 586 engages the threads of tee 554 which previously retained the 
drip leg. Wand 566 is then rotated so as to be integrally and rigidly 
threadingly retained on tee 554, and inner wand 568 is then inserted 
further into outer wand 566. Threaded collar 604 then engages threaded 
section 574 and is used to control the movement of inner wand 568. As 
inner wand 568 moves further inward, stopper 606 abuts the inner edge fuel 
pipe 622 (see FIG. 25). As collar 604 in tightened, gas flow from service 
26 is, of course, eliminated and feed pipe 622 is thus supplied solely via 
hose 560 and bore 590. Meter supply valve 28 (see FIG. 1) may then be 
closed and meter 24 may be removed for service or can be replaced. 
After meter 24 has been reinstalled, the gas meter-bypass equipment is to 
be disconnected and removed. First, however, it is necessary to evacuate 
air within both meter 24 and service 26. Therefore, a hose is attached to 
snap fitting 620 and led outside. Valve 28 in then opened and any air is 
purged by being forced through seal jacket 612 to snap fitting 620. When 
such flow is determined to be pure gas, the hose is disconnected and snap 
fitting 620 automatically closes. Threaded collar 604 is then loosened and 
inner wand 568 is withdrawn. When snap ring 584 again abuts plug seal 614, 
valve 40 and slide valve 558 are closed. Hose 560 and gas wand 564 are 
then removed. Tee plug 20 and, finally, the water trap cap are both 
replaced. Accordingly, the present invention has provided equipment and a 
procedure to remove and replace a gas meter without the interruption of 
gas service. 
It will be appreciated that various modifications of the foregoing 
apparatus and procedures are within the purview of those skilled in the 
art and those modifications and the like are intended to be covered by the 
following claims: