US 3104456 A
Description (OCR text may contain errors)
Sept- 24, 1963 J. s. POWELL, JR 3,104,456
METHOD OF CONNECTING SERVICE LINES TO MAINS Filed June 27, 1960 2 Sheets-Sheet l 55/ #is rra/eME/s.
,Mlm/s, .1f/ECW, .IQUSSELL He/QM Sept. 24, 1963 J. s. POWELL, JR 3,104,456
METHODL oF CONNECTING SERVICE LINES To MAINS Filed June 27, 1960 2 Sheets-Sheet 2 Ca/V4 r//AA/ 5.' pan/5u, Je,
United States Patent O METHD F CGNNECTNG SERVQE LHNES T li/APJS Jonathan S. oweli, fir., 1231 Eroolrmere Road, Pasadena 2, Calif. Filed .lune 27, 196i?, Ser. No. 38,922 2 (Ilaims. (Cl. 29-157) The present invention relates in general to amethod of and apparatus for making service line connections to gas mains, water mains, and the like, without service interruptions to existing service line connections.
It will be understood that the term main is used herein to designate any duid-conveying conduit, and the expression service line, as used herein, means any branch duid-conveying conduit connected to such main A general object of the invention is to provide an apparatus for and a method of making service line connections which are respectively much simpler and much less time consuming, and thus far less expensive, than prior apparatuses and methods. Other general objects are to provide service line connections which avoid exposed underground threaded connections, which are easily protectible from corrosion, which avoid the necessity for initially providing the mains with projecting fittings when the mains are laid, thereby avoiding the possibility of having such projecting ttings broken ol by digging equipment, and the like.
More specically, a primary object of the invention is to provide a service line connection and method which involve connecting a lateral stub conduit or nipple to the main or main conduit, and forming a hole through the main to establish communication between the main and the nipple and, at the same time, preventing the escape of uid from the main by isolating the portion of the main being Worked on from the atmosphere and by plugging the nipple with a lfusible plug. Subsequently, the service connection is completed by connecting the service line to either the main or the nipple. As a iinal step, the fusible plug in the nipple is heated, by the external application of heat, to melt out the fusible plug, thereby establishing communication between the main and the service line after the service connection has been completed, which is an important object of the invention.
Another object is to provide a service connection wherein the service line is either connected directly to the main around the nipple, or is connected to the nipple itself.
A further object is to make all exposed connections between the service line and the main, or between the Serf vice line and the nipple and between the nipple and the main, bonded connections so that there are no exposed threaded connections. Such bonded connections may be welded connections in the event that the various components are made of weldable metals, or they may be cemented connections in the case of plastic components. Also, the bonded connections in question may be heat sealed connections with heat scalable plastic materials.
The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the art to which the invention relates, may be achieved with the exemplary embodiments of the invention described in detail hereinafter and illustrated in the accompanying drawings, in which:
FIGS. 1 to 5 are semidiagrammatic, transverse sectional views, with certain components in elevation, illustrating successive steps of one embodiment of a method of connecting a service line to a main in accordance with the invention;
FIG. 6 is an elevationalview of a main having partially completed service connections thereon;
FIG. 7 is a transverse sectional View taken along the arrowed line 7-7 of FIG. 6;
FIGS. 8 to 10 are semidiagrammatic, transverse sectional views, with certain components in elevation, which are similar to FIG. 7, but which illustrate successive steps or" another embodiment of the method of the invention for completing the partially completed service line connection shown in FIG. 7;
FIG. l1 is an enlarged sectional View taken along the arrowed line 1l-ll of FIG. 10; l
FIG. 12 is a View similar to PIG. 10, but illustrating still another method of making a service line connection in accordance with the invention;
FIG. 13 lis an enlarged sectional View taken along the arrowed line 13-13 of FIG. 12; and
FIG. 14 is a view similar to'FlG. 9, but illustrating yet another apparatus and method of making a service line connection inV accordance with the invention.
Referring first to FIGS. l to 5 of the drawings, the numeral 2i) designates a main, such as an underground gas main, water main, or the like, to which a service line 22 isto be connected. The steps required to connect the service line 22 to the main Ztl will now be considered sequentially.
Initially, a suitable tool 24 is attached to the main 20, as by means of a clamp 26. The tool 24 provides a space 28 which is isolated from the atmosphere and one end or side of which is bounded by the main 263. More particularly, the tool 24 provides an annular packing means 39, shown as a simple O-ring for convenience, which engages the main Ztl on one side thereof to form one end of the isolated space 28. The other end of the isolated space 28 is formed either by a closure means 32, or by an annular packing means 34, shown as a simple O-ring for convenience, engageable with components to be described. The closure means 32 is shown, for purposes of illustration, as comprising simply a gate valve 36 engageable with a valve seat 3S.
The next step is to insert into the tool 24 a combined drilling and tapping means 4i) having a shank l2 engageable with the annular packing means 3d in a duid-y tight manner to form the outer end of the isolated space 28. Under these conditions, the gate valve 36 is out of engagement with its seat 3S. The shank 42 of the drilling and tapping means 46 terminates in a stem 44 which projects from the outer end of the tool 24 through a feed screw 46 engageable with an annular shoulder 47 on the drilling and tapping means. As will be clear from FIG. 1 of the drawings, by simultaneously rotating the drilling and tapping means 40 and the feed Vscrew 46, a hole i8 is drilled in the main 2) and is subsequently tapped. The drilling and tapping means d@ and the feed screw 46 may be rotated in any suitable manner, as by applying wrenches, not shown, to t-he outer ends 5t) and S2 of the stern da and the feed screw 416, respectively. `Once the hole 48 is drilled and tapped, it establishes Huid communication between the main 20 and the inner end of the isolated space 2S. The isolated space 28 is provided adjacent its inner end with a well 29 which receives cuttings produced by the combined drilling and tapping means 40 so that such cuttings are prevented from entering the closure means 32 and the packing means 34 to damage same.
Next, as shown in FIG. 2 of the drawings, the drilling and tapping means 40 is partially Withdrawn from the isolated space 2S, whereupon the gate valve 36 is re-engaged with the valve seat 3S to close the outer end of the isolated space toV prevent the loss of uid from the main 2l). Next, the drilling and tapping means 40 is com-,
pletely withdrawn from the tool 24 by completely unscrewing the feed screw 46.
Then, as shown in FIG. 3 of the drawings, a nipple 5d Patented Sept., 24, i963.
is inserted into the tool 24 and into Huid-tight engagement with the packing means 34, whereupon the gate valve 35 may be disengaged from its seat 38 to permit threading of the inner end of the nipple into the tapped hole 4S. The nipple 54 is provided at its outer end with a reduced-diameter stem 56 providing an annular shoulder S7 corresponding to the annular shoulder 47 on the drilling and tapping means 40 and engageable by the feed screw 46. As will be apparent, the feed screw 46 may' be rotated to advance the nipple 54 until the inner end thereof engages the main 2d, whereupon the nipple may be rotated to thread the inner end thereof into the tapped hole 43. Since the feed screw 46 is utilized to guide both the drilling and tapping means 4i? and the nipple 54, the inner end of the nipple is brought into accurate register with the tapped' hole 45.
The nipple 54 is provided at or adjacent its outer end with a fusible plug 58 of `a metal, or metal alloy, having a relatively low melting point. The fusible plug 5S must be capable of withstanding the pressure in the main 2t? and in many instances this may be achieved merely by pressing the plug into the nipple 54. In the event that very high main pressures must be sustained, the interior of the nipple 54 may be roughened, grooved, or the like, and the plug 5S cast in place so that it is keyed to die nipple.
After the nipple 54 has been threaded into the tapped hole 48, the tool 24 is detached from the main Ztl, thereby arriving at the condition shown in FIG. 4 of the drawings. Under these conditions, the fusible plug 5S prevents loss of fluid from the main 20 while the service line 22 is being connected thereto, as will now 'be described.
Referring to FlG. 5 of the drawings, thev next step is to slip the service line 22 over the nipple 54, whereupon the inner end of the service line may ybe welded -to the main 29, as indicated at 6i). The necessary hookup of the service line Z2 is then completed. For example, the Iservice line 22 may be connected to `a `gas meter associated with a residence.
Finally, after completing the entire service line installation, the fusible plug 58 is melted out, as by playing the ame of a torch 62 on the service line 22 opposite the fusible plug. ri`he heat generated in this fashion melts the surface of the fusible plug 58, whereupon the pressure in the main 2t? blows the plug out of the nipple 54. The resulting remnant of the fusible plug 58 remains in the service line 22 and is small enough that it produces no significant obstruction.
The melting temperature of the 'fusible plug 58 and the length of the nipple 54 are such that the heat generated in welding the service line 22 to the main 26 does not heat the nipple at the plug suticiently to loosen the plug. For example, assuming that the main 2G, the service line 22 and the nipple S4 are all made of ordinary pipe, it has been found that, with a nipple length of approximately eight inches, the plug temperature reaches only about 220 F. during 4the course of Welding the service line 22 to the main 2h. Thus, making the fusible plug 53 out of a metal or metal alloythat melts at 275 F. provides an Iample margin of safety.
yWhile the nipple 54 is shown as smaller than and spaced radially inwardly from the service line 22, ythis is not `absolutely essential, although Ithe radial spacing does reduce transmission of the welding heat to the fusible plug 5S, which is desirable. Also, the nipple 54 has, as a lmatter of convenience, .been shown somewhat longer,
in relation to its diameter, than would be the case in actual practice. Further, in actual practice, the shoulder 57 engageable by the feed screw 46 lis preferably closer to the outer end of the nipple 54, i.e., closer to the end thereof containing the fusible plug 58.
It will be noted from the foregoing that the present invention provides a very simple method of connecting the service line 22 to the main 20 and one which can be made rapidly with simple and inexpensive components,
s thereby minimizing the cost of making the connection. Further, since the service line is welded to the main 2) there are no exposed threaded connections so that corrosion problems are minimized. Further, with the simple structure of the connection which the invention provides,
it may be protected `against corrosion readily, may be wrapped readily, or the like. Still another .advantage is that there is no necessity of initially providing the main 20 with fittings which can corrode, be lbroken olf, or the like, prior to use.
Turning now to FIGS. 6 to ll'of the drawings, the
embodiment of the invention illustrated therein employsk the same basic concepts as that hereinbefore described, but utilizes somewhat different components and somewhat different steps.
Referring first to FIG. 7 of the drawings, the rst step with this embodiment is to weld a nipple 70 to a main 1 v 72. The nipple '70, in this instance, ultimately forms a part of the service line. j' The next step is to slip over the nipple 72 a tool 74 which is similar to the tool 24 and cor-responding com'- ponents of which are identified by the same vreference y numerals. The tool 74 differs from the tool 24 in that, instead of being seated against the main '72, it is seated against the outer end of the nipple '70 and is provided with an annular packing means 76, shown as a simple Oring, engageable with the exterior of the nipple 7G and sealing the inner end of the isolated space 28. The toolv The drill SG is similar to the drilling and tapping means 4) and identical reference numerals are employed to p designate corresponding components.
Elaborating on the foregoing paragraph, the drillt) is inserted into the tool 74 until the shank 42 thereof engages the packing means 54 in a fluid-tight manner.
Thereupon, the valve 36 is disengaged from its seat 38 and, by means of the feed screw 46, the drill S0 is brought a Subsequently, by simultaneously rotating the drill and the feed screwV into engagement with the main 72.
46, a hole 82 is drilled in the main 72 at the inner end of the nipple 7i). Subsequently, the drill 80 is withdrawn,
the gate valve 36 being seated prior to disengaging the shank 42 of the drill from the packing means 34.
Referring to FIG. 9, the next step is to insert a plug means S4 through the tool 74 into the nipple 7). This insertion is effected with a rod 86 which carries the plug means 84, the rod 86 first engaging the packing means 34 in a fluid-tight manner, whereupon the gate valve V36 may be unseated to permit insertion of the plug means 84 into the nipple '70. The feed screw 46 may act on the rod 86 during the course of inserting the plug means 84 in the same manner that it acts on the drill 80, the rod 86 being rovided with an .annular shoulder, not shown, corresponding to the annular shoulder 47. Subsequently, the rod 86 is withdrawn from the nipple 7? and the tool 74, and the tool is then detachedA The plug means 84 includes a collar 88' carrying a fusi-ble plug 90 in the form of a disc set in an internal Y annular groove in Ithe collar. The collar 88 carries externally thereof an O-ring 92 which makes a fluid-tight seal with the interior wall of the nipple 70. The collar 33 is held in place within the nipple '70 against the pressure Ywithin the main 72 by a Washer 94 against whichthe outer end of the collar 88 is seated and which is provided with prongs 96 adapted to bite into the interior wall of the nipple 70. Such a washer `94 is capable of holding the plugged collar 88 in place against substantial main pressures.
'Phe next step is to weld a service line 98 to the outer end of the nipple 70, the nipple in this instance forming a part of the service line. service line 9S is completed.
rFhe nal step is to heat the nipple 70 opposite the plug means S4 suiciently to melt out the fusible plug 90 in the same manner as the fusi-ble plug 53, lthe collar 88 and the washer 94 remaining within the nipple 70.
As in the case of the embodiment yof FIGS. 1 to 5 of the drawings, the location of the plug means 84 relative Ato the weld between the nipple 7) and the service line 98 and the melting temperature of the-fusible plug 90 are such that the heat generated in welding the service line 98 to -the nipple 70 will not melt out the fusible plug 90. Also, the fusible plug 90 may -be protected from the welding heat at the connection between the service line 98 and the nipple 7 il by making the collar 88 of a heat insulating material. Doing this, however, requires the application of more heat to the plug means 34 in the course of meltin out the plug 99.
Referring to FIGS. 12 and 13 of the drawings, illustrated therein is a service connection to a main 110 comprising a nipple 112 and a service line 114, communication between the main 110 and the nipple 112 being established through a hole 116 in the main. In this case, the main 110, the nipple 112 and the service line 114 are all formed of suitable plastic materials bon-ded together by Then, the hookup of the cementin-g, heat sealing, or the like, instead of by welding.
To provide stronger connections, the nipple I112 terminates at its inner end in a saddle 118 complementary to the main 110, and, for the same reason, la telescoping connection 121) is provided between the nipple 112 :and the service line 114.
In making the service connection of FIGS. 12 and 13, the nipple 112 is first bonded to the main 110. The hole 116 is then drilled in substantially the same manner as and with substantially the same equipment las the hole 82 in the main 72. Then, a fusible plug 122 is inserted into the nipple 112 in substantially the same manner as and with substantially the same equipment as the plug means S4. The fusible plug 122 is preferably snapped into an annular groove 124; in the nipple 112, the plastic material of which the nipple is formed being suiiciently flexible to permit this. The fusible plug 122 is provided thereon with -a central boss 126 receivable in a hole in a rod, not shown, similar to the rod 86 Ifor inserting the plug means 84. The boss 126 thus serves as -a means vfor connecting the fusible plug 122 to such a rod during the insertion process.
Next, the service line 114 is bonded to the nipple 112 at the telescoping connection 120, either by cementing, heat sealing, or -the like.
After the service line 114 has been completely hooked up, the fusi-ble plug 122 is melted out by applying heat to the nipple 112 opposite the fusible plug. In this instance, the fusible plug 122 may be made of a metal or metal alloy having a -rather low melting point so that it can be melted out without overheating the plastic nipple 112. Preferably, Woods met-al is used since, under such circumstances, the fusible plug 122 can be melted out merely by pouring hot Water over `the nipple 112 opposite the fusible plug. However, it will -be understood that the fusible plug 122 maybe melted out in other ways.
Referring to FIG. 14 of the drawings, illustrated therein is -an alternative method of establishing communication between the nipple 7d and the main 72 and of preventing the escape of fluid from the main until the service line 9S is connected to the outer end of the nipple. Instead of drilling the hole @2 of FIGS. 8 to l() in lthe main 72, a somewhat smaller hole 130 is drilled and tapped therein through the use of a tool 132 -similar to the tool 74 and through the use of a drilling and tapping means, not shown, similar to the drilling and tapping means y411. In this case, the tool 132 is anchored in place by set screws 134 engageable with the nipple 70, instead of by a mainencircling clamp.
After the hole 131i has -been -drilled and tapped `and the drilling and tapping means withdrawn from the tool 13.2, a plug means in the form of =a second nipple .136 is inserted into 'the nipple 7 il and is threaded into the tapped hole 130. The nipple 136 is provided at its outer end with a noncircular, preferably hexagonal, socket 13S adapted to receive a complementary plug 140 on the inner en-d of an inserting tool 142 capable of engaging an annular packing means of the tool 132 corresponding to the annular packing means 34. The nipple 136 is inserted and threaded into the tapped hole with the inser-ting tool `141-2 in much the same manner as the plug means 84 is inserted with the inserting tool or rod y86.
The nipple 136 is provided therein with a fusible plug 144 which is retained therein in much the same manner as the fusible plug 58 is retained in the nipple 54.
-After a service line, not shown, Ihas been -welded to the outer end of the nipple 70, and after the hookup of the service line has 'been completed, the nipple 70' is heated opposite the -f-usible plug 144 in the inner nipple 136 to release the fusible plug, thereby establishing communication between the main 72 and the service line.
The embodiments of the invention illustrated -in FIGS. 6 to 11, in FIGS. 12 land 13, and in FIG. 14 have substantially the same advantages as the embodiment illustrated in FIGS. 1 to 5 so that a further description is unnecessary.
Although exemplary embodiments of the invention have been disclosed herein `for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as dened by the claims which follow.
1. A method of connecting a weldable service line to a Awelclable main intermediate the ends thereof, including the steps of:
(a) welding an inner end of .a weldable nipple directly to the peripheral wall of said main with said nipple projecting laterally `from said main;
(b) isolating a space which is axially aligned with said nipple rand which communicates at an inner end thereof with the outer end ccf said nipple;
(c) inserting a drill axially into said space through the outer end thereof and `axially into said nipple through the outer end thereof, while simultaneously maintaining the isolation of said space;
(d) drilling a hole through said peripheral wall of said main with said drill from the exterior of said space, -whereby to connect said main and the innen end of said nipple in fluid communication;
(e) withdrawing said drill axially from said nipple and said spiace while simultaneously maintaining the isolation of said space;
'(9) inserting a plug having a fusible portion axially into said space through the `outer end thereof land axially into said nipple through the outer end thereof, while simultaneously maintaining the isolati-on of said space;
(g) securing said plug within said nipple :adjacent the inner end thereof from the exterior of said space;
(h) ideisolating said space;
(i) welding an end of said service line directly to the outer end of said nipple; and
(j) heating said plug through said nipple suiciently to melt said fusible portion thereof, whereby to conneet said service line in fluid communication with said mainthrough said nipple.
2. A method of connecting `a Weldable service line to a weldable mainintermediate the ends thereof, Iincluding the steps of:
(a) welding an inner end of a weldable nipple directly to the peripheral wall of said main with said nipple projecting laterally from said main;
(b) isolating a spiace which is axially aligned with said nipple and which communicates :at an inner end thereof with the outer end of said nipple;
(Ac) inserting a hole-fonming member axially into said space through the outer end thereof `and axiallyinto said nipple through the outer end thereof, fwhile simultaneously maintaining the isolation of `said spaee;
(d) forming Ia hole through said peripheral Wall of said main with said hole-forming member from the exterior of said space, whereby yto connect said main -and the inner end of said nipple in iluid communication; Y
(e) withdrawing said hole-forming member axially from said nipple and said space while simultaneously maintaining the isolation of said spaee;
(f) inserting 1a plug having a fusible portion axially into said spiace through the outer end thereof Iand laxially into said nipple through the outer end fthereof, while simultaneously maintaining the isolation of said space;
(g) securing said plug within sai-d nipple fadjafcent lthe inner end thereof from the exterior of said space;
' 8 (h) deisolating said-space; L welding an end of saidserviee line directly to the louter end of said nipple; and
(j) heating said plug through said nipple suliciently mo lrneltt said .fusi-ble portion thereof, whereby to con` neet said servi-ee line in uid .communication with Y, Y
said main through saidnipple.
vReferenees Cited in the le of this patent UNITEDl STATES PATENTS