US3368005A - Process of sealing a bell and spigot joint - Google Patents

Description

Feb. 6, 1968 G. s. BuczALA ETAL 3,368,005

PROCESS OF SEALING A BELL AND SPIGOT JOINT original Filed March 27, 1965 4 sheets-sheet 1 y BY 41n l KK 1..., 'LS-- 5 oRNEYs Feb. 6, 1968 G. s. BUCZALA ETAL 3,368,005

PROCESS OF SEALING A BELL AND SPIGOT JOINT original Filed March 27, 1963 4 sheets-sheet' 2 Feb- 6, 1968 G. s, BUCZALA ETAL 3,368,005

PROCESS OF' SEALNG A BELL AND SPIGOT JOINT Original Filed March 27, 1965 4 Sheets-Sheet 5 ATTORN EYS Feb, 6, 1968 G. s. BuczALA ETAL 3,368,005

` PROCESS OF SEALING A BELL AND SPIGT JOINT Original Filed March 27, 1965 4 Sheets-Sheet 4 l VENTOIS United States Patent Ottice 3,358,005 Patented Feb. 6, 1968 3,368,005 PROCESS OF SEALING A BELL AND SPIGOT JOINT George S. Buczala, 306 Church Road, Abington Township, Montgomery County, Pa. 19001, and Walter E. Rosengarten, Jr., 2895 Gradyville Road, Broomall, Pa. 19008, and Lynn L. Copeland, Philadelphia, Pa.; said Copeland assignor to said Buczala and said Rosengarten jointly Original application Mar. 27, 1963, Ser. No. 268,388, now Patent No. 3,260,280, dated July 12, 1966. Divided and this application Mar. 24, 1966, Ser. No. 554,225

9 Claims. (Cl. 264-32) ABSTRACT F THE DISCLOSURE A process for sealing a bell and spigot joint in a pipe line buried beneath a paved area which comprises breaking the paving in an area less than one square foot directly over the joint, and through this opening excavating around the joint, blast cleaning the face of the bell and the adjoining spigot, applying and securing an expendable mold about the joint, and forcing sealant into the mold cavity. The mold is of rubberized fabric in the form of an overlapping girdle which in released position conforms to the shape of the joint and has a bell end portion, a spigot end portion and an inclined intermediate portion which includes the mold cavity and in the preferred embodiment is provided with a iill tube and a tensile spring engageable therewith. Longhandled tools are used to apply the mold, to connect the spring to the fill tube and to apply and tighten respective steel banding straps around the bell and spigot end portions of the mold.

The present invention relates to a process for sealing mains, and particularly for sealing bell and spigot joints i in existine mains, carrying iluid such as fuel gas, water and other Huid.

A purpose of the present invention is to provide a method of using an expendable mold for receiving sealant for sealing leaks in bell and spigot joints.

A further purpose is to provide a method of using a mold which can be applied to a joint at the bottom of an excavationfrom a position at the surface of the excavation.

A further purpose is to be able to inject sealant into a mold at the bottom of an excavation from a position at the surface of the excavation.

A further purpose is to be able to backiill a hole immediately after the sealant has been injected into the mold.

A further purpose of the invention is to seal gas mains at the bell and spigot joints by means of a mold applied by an operator located at a point remote from the main.

A further purpose is to use commercially available steel banding for applying the mold on a joint.

A further purpose is to use a mold to create a cavity which extends outwardly from the joint packing space for the reception of a sealant.

A further purpose is to reduce the size of the hole necessary to gain access to the main to seal the joint.

A further purpose is to reduce the area of paving destroyed to gain access to seal the joint.

A further purpose is to keep the main in service while the joint is being sealed.

A further purpose is to provide a method of using an expendable mold which can compensate for variations from true roundness or lack of concentricity in the main or lack of angular alignment between the adjoining lengths of pipe.

Further purposes appear in the specitication and in the claims.

In the drawings we have chosen to illustrate one embodiment only of the device for sealing the leak, choosing the form shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURE 1 is a perspective view of the mold of the invention applied to a pipe joint.

FIGURE 2 is an enlarged longitudinal vertical section of the mold of the invention applied to a bell and spigot joint.

FIGURE 3 is a section transverse to the axis of the pipe taken on the line 3 3 of FIGURE 2.

FIGURE 4 is a section transverse to the axis of the pipe taken on the line 4 4 of FIGURE 2.

FIGURE 5 is a fragmentary section transverse to the axis of the pipe similar to FIGURE 3 showing a variation in the overlap.

FIGURE 6 is a section transverse to the axis of the pipe taken on the line 6-6 of FIGURE 2 showing the inlet tubing.

FIGURE 7 is a fragmentary section transverse to the axis of the pipe similar to FIGURE 6 showing the sealing flap in the relaxed position.

FIGURES 8 through 16 show the application of the mold to a pipe joint.

FIGURE 8 is a transverse section with respect to the pipe showing the mold in elevation being lowered into the hole.

`showing the step illustrated in FIGURE 11.

FIGURE 13 is a section transverse to the axis of the pipe showing the insertion of a band around the joint.

FIGURE 14 is a view transverse to the axis of the pipe showing the closed band with the free end of the steel band hooked behind the buckle.

FIGURE 15 is a section transverse to the axis of the pipe showing the use of the extension tensor to tighten the band around the mold. This view also illustrates a special wrench for tightening the band.

FIGURE 16 is a view similar in position to FIGURE 15, but showing the insertion of the sealant into the mold.

FIGURE 17 is a fragmentary elevation partly in section of the special wrench of the character employed in FIGURE 15.

Describing in illustration but not in limitation and referring to the drawings:

In the distribution of gas for domestic, commercial and industrial use, a network of mains is employed to carry the gas from central points to points of usage. These mains in many instances have bell and spigot joints which are typically packed by jute and then usually leaded or cemented at the outside. When these joints were originally installed, many of the mains were distributing carbureted water gas or coke oven gas or other manufactured gas which contained a substantial content of moisture, tars and oils. These liquids had over a period of time saturated the packing materials to provide relatively leak-free joints.

In recent years there has been a shift over to natural gas which is of a comparatively dry nature. The natural gas has reduced by absorption the content of tars and oils which has been built up in the joints, thus drying out the joints. Furthermore, many of the textile packing materials tend to shrink when they dry. The result encountered in a widespread Way has been a tendency of the packing t shrink, causing openings through the dried out packing which permit leakage of gas.

In other instances leaks have been caused in many areas of the country by active earth conditions which in certain localized areas has involved settling or movement of the earth in the order of a half inch or even one inch a year. This settling has caused a certain tendency for misalignment of the various pipe sections, both vertically and also horizontally and this has further increased the tendency toward leakage. This misalignment in some instances has caused a Withdrawal to some extent of the pipe from the spigot `causing additional leakage.

All of these factors have made it quite important to develop some technique for sealing the joints. One approach to the problem has been to cut out the line, and actually introduce a self-propelled plug, which cleans the line and locates the joint, sometimes electronically, and then to coat the inside with a suitable sealing compound.

This involves several complications, the worst of which is taking the line out of service and the need to provide an alternate temporary supply to the customer and also the need to operate on relatively straight pipe stretches and not on pronounced bends.

In order to overcome the disadvantages of sealing by a self-propelled crawler inside the line, extensive use has been made in some areas of external sealing techniques, which may be used without taking the line out of service. These usually involve digging an excavation at each joint large enough for a man to descend to the area around the bell or pipe and to iix a bolted clamp fitting around the joint. The iitting compresses a rubber gasket which seals against the outside of the bell and `also against the adjoining straight pipe section of the spigot.

There is also another technique which in effect butters epoxy resin around the face of the bell in order to accomplish sealing. This method also requires extensive excavatio-n.

The present invention, as in copending application Ser. No. 192,817, for Process and Apparatus for Sealing Mains, filed May 7, 1962, permits the line to remain in service at normal pressure without any interruption of gas iiow, and permits the line to be repaired with a minimum of excavation. The process and equipment can function using a slit about 18 inches in length and about 4 inches in width Where it penetrates the sidewalk or other paving, and slightly wider in the earth at the bottom where the pipe joint is located. Thus it Will be evident that successful operation can be carried on through an opening which is less than 1 square foot in area and in many cases as small as 1/2 square foot in area at grade in the paving. In addition, in the present invention the excavation can be backlilled immediately after the repair is made so that a minimum of inconvenience is caused to the public.

The present invention as compared to any preformed gasket technique gives a greatly improved seal by providing a bond to the metal surface.

Principally due to the reduced amount of excavation, the speed of the operation is considerably increased compared to the other techniques. It is believed that the time is not more than one-half that of the best prior technique.

By virtue of the relatively small size of the opening in the paving, it is much less costly to repave after sealing the leak than it was in prior art methods. In addition,

highway authorities have permitted openings of this size in paving to be repaired with a mere block of concrete rather than extensive cutback and repaving according to specification. This provides quite substantial savings. Also, it is usually possible to work around reinforcing rods in concrete paving, thus eliminating the necessity for replacing and/or tie-welding new rods with repaving. Furthermore, the repair to the paving can be made immediately.

In accordance with the present invention, a cleaning technique is employed, which may conveniently be sand blasting but could be grit blasting, wheat blasting or refractory blasting. Alternatively the joint could be cleaned by wire brushing, scraping or by solvent. After the cleaning has been completed, a mold is introduced about the joint more or less by remote control since the operator is at ground level. A suitable sealing material is introduced under pressure into the mold space. The mold is left in position about the pipe or joint, the sealing material inlet tube extension is disconnected from the mold and the excavation is immediately backiilled.

The preferred sand blasting device and technique is set forth in copending application Ser. No. 192,817 referred to above. This device and technique consist essentially of a rotating element having a nozzle adapted to sand blast the pipe, the rotating element being manipulated remotely from the main by means of a handle.

The present invention is adapted to be used on a joint of the type comprising lengths of pipe 20 and 21. Pipe 2() has a bell 22 having a flange 23, a Web 24, a longitudinally and circumferentially extending surface 25 and a radially and transversely extending face 26. The spigot 27 is in effect an integral extension of pipe 21 having the same inside and outside diameter. The outer circumference of the spigot 27 and the inner circumference of the bell 22 form a space having a circumferentially extending portion and a radially extending portion. Jute packing 28 occupies the radially extending portion and a part of the circumferentially extending portion and a lead packing 30 extends circumferentially at the remaining part of the space not occupied by the jute.

Considering now the mold itself as shown in FIG- URES 1 through 7, a girdle Si) has a circumferential longitudinally extending spigot portion 53, a circumferential longitudinally inclined cavity-forming portion 52, and a circumferential longitudinally extending bell por tion 51. The girdle portions 51, 52 and 53 are permissibly integral but as shown are desirably of separate elements cemented or sewn together at longitudinal overlap positions 47 and 48, and further connected by circumferentially extending reinforcing cemented rubber tapes 54 and 55. The girdle portions 51 and 53 are composed suitably of an outer layer of rubberized fabric 56 laminated to an inner layer of foam rubber 57. The diagonal or intermediate portion 52 is of a rubberized fabric of the type employed at 56.

The mold 50 in a relaxed position conforms to the diameter and shape of the bell and spigot joint to which it is to be applied.

The mold is separated longitudinally at overlap 58 with an inner lap 60 and an outer lap 6l. In FIGURE 3, the outside lap 61 has the foam rubber 57 terminating at the end of lap 61. In an alternative shown in FIGURE 5, the foam rubber 57 terminates short of the overlap 61 to permit a closer engagement as at 59.

The inner lap 60 of girdle portion S2 has a thin flexible plastic or fabric film Hap 62 adhesively connected at 63 as best seen in FIGURES 6 and 7. The flap 62 tends to remain smooth against the stiffer material of girdle portion 52 when subjected to internal pressure. The inner lap 60 extends between flap 62 and outer lap 61 as seen in FIGURES 6 and 7.

In FIGURE 6, the iiap 62 is shown in a stressed position, and in FIGURE 7, the flap 62 is shown in an unstressed position.

A till tube 65 as best seen in FIGURE 6 is composed of a tube portion 66 and a iiange portion 67. The tube portion 66 its through a circular opening 68 in the intermediate portion 52 of the girdle and is held in place by flange 67 which is suitably cemented to portion 52 at 69.

A helically wound tension spring 70 having a hooked end 71 is anchored to a Dring cemented or otherwise secured to girdle portion 52 at 72.

The girdle 50 will be held in position over the joint by steel straps 80 and 81 which extend over the bell portion 51 and the spigot portion 53 of the girdle 50. These straps 80 and 81 are of a well known commercial type consisting of a band 82 and a buckle 83. One end of band 82 is secured in buckle 83 by a bend 84 and the opposite end of baud 82 is held in buckle 83 by a bolt 85.

It will be noted that the band of strap 80 is placed over the bell portion of the girdle 51 over circumferentially extending surface 25 of the bell 22. This is best seen in FIGURE 2. Likewise steel strap 81 extends around girdle portion 53 to secure the portion to spigot 27.

As seen in FIGURE 2, the joint and girdle form a cavity 90 which is annular and which is of a generally triangular longitudinal cross section. The cavity 90 is defined by bell transverse face 26, lead packing 30, spigot 27, and by the girdle portion 52. A small portion of the foam rubber at 91 completes the cavity definition.

In operation, a hole is excavated about the joint by the use of long handled tools from the surface. This excavation can be of approximately 18 inches in length and about 4 inches in width at the surface where it penetrates the sidewalk or other paving. The excavation is made slightly larger at the base in the area of the joint so that the mold can be properly manipulated.

Referring to FIGURE 8, the girdle S0 is lowered into excavation 100 from surface 101 by grasping the lill tube 65 with a pair of straight tongs 102. It will be evident that prior to the insertion of the mold into the excavation, a hose 103 has been connected to the fill tube 65 as by a suitable clamp 103. The mold will extend in a slightly curved fashion so an operator can manipulate the hose around the joint until the girdle assumes the position shown in FIGURE 9.

As shown in FIGURE 9, the tongs 102 are used to slide the mold around the joint. Because of the molds resilience it will stay in almost a closed position around the joint. The hook 71 of spring 70 is then grasped by the offset tongs 104 and hooked around the lill tube 65 as shown in FIGURE 10. The spring 70 keeps the mold circumferentially positioned about the joint.

Using a long handled yoke 105 having a straight handle 106 and a yoke portion 107, the mold is tapped longitudinally at the spigot portion 53 to insure that the mold is up against the bell 22, as shown in FIGURES 11 and 12. The mold is now in position for application of the steel straps 80 and 81.

A buckle 83 is applied to the steel band 82 which is played out from a coiled roll (not shown). The buckle 83 is tightened along the band 82 by bolt 85 and secured lightly thereto so that it does not slip down. The strap 82 is then placed along one side of the spigot portion 53 of the girdle 50 until it curls around the spigot portion 53 and comes up on the other side as shown in FIG- URE 13. The band 82 is manipulated from the excavation surface 161. Straight nosed tongs or pliers 108 are used to grasp the free end of the band at 110 and the free end is brought to the surface 101. The free end 110 is threaded through buckle 83 and bent back on itself at 84 as in the normal banding fashion. The buckle 83 is then pushed down along the band '82 as far as can be reached by hand from the surface 101 as shown in FIGURE 14.

The side slot of the tensor head 111 of a conventional band tensor 112 having an elongated handle 113 extends from the hole. The tensor head 111 is pushed down against the buckle 83 and the strap is pulled up snugly as in FIGURE 15.

The conventional handle 114 at the top of the tensor 112 is rotated to tighten up the band 82 about the spigot 27. When the band is suiciently tight a special Wrench 115 with three universal joints is used to engage and tighten the bolt on the buckle 83 as shown in FIGURE 15. The special wrench includes a tube 83 suitably bent to degrees, having at one end a crank handle 832, suitably journalled on a bearing 833, which connects to a series of suitably three universal joints 834 connected end to end in the bend of tube 83 and at the output end suitably journalled in a bearing 835 and connecting to a socket wrench 836. Thus it will be evident that torsional force applied at the crank end is made effective at right angles in the socket wrench.

When the nut 85 on the buckle 83 has been tightened, the steel band 82 is cut adjacent to buckle 83 by operating the conventional cut-off lever 116 of the band tensor 112 by forcing handle 117 downward.

The same procedure is followed for placing strap 80 on the bell portion 51 of the mold.

After both bands have been placed and properly secured the mold is ready for injection of the sealant. The sealant is preferably of a type which will partially harden but which will remain flexible throughout its life.

In FIGURE 16 there is shown the step of injecting the sealant into the mold by the use of a uid pump 118 of any well known type which connects through inlet hose 103 to ll tube 65.

The flap 62 acts as a valve which permits the air being displaced by the sealant entering the cavity 90 to escape through the overlap 58 of girdle portion 52 but prevents similar escape of the highly viscid sealant.

The sealant is of a material of such viscosity that it will not leak out through the mold even though the mold would not be tight to water.

A gauge 123 or other technique, such as observing diiculty in further operation of the pump 118 or, for instance, a grease gun, is used to indicate when the cavity 90 is completely filled with sealant.

After the sealant has been injected into the mold and the inlet hose 103 secured against leakage as, for instance, by bending the hose 103 into a kink and tying the hose, the hose is disconnected from the pump at 122 and allowed to drop into the hole. The hole can be immediately backlled.

In view of our invention and disclosure, variations and modiiications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benets of our invention without copying the process shown, and we, therefore, claim all such insofar as they fall within the reasonable spirit and scope of our claims.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. The process of sealing a bell and spigot joint in a pipe main at the bottom of an earth excavation with a circumferentially overlapping longitudinally flexible resilient mold having a till tube and a helically wound tensile spring adapted to be connected to said fill tube for holding said mold in wrapped engagement with said joint comprising the steps of blast cleaning the face of the bell and the adjoining spigot, using tongs to grasp the lill tube and lower the mold into the excavation about the joint, allowing the mold to return to its natural circular position about the joint, grasping said spring with tongs to connect said spring to said ll tube, tapping the mold longitudinally into abutting relationship against the bell, lapplying a coiled metallic band around the joint, tightening the band to tightly squeeze the mold about the bell and spigot, whereby the mold forms an annular cavity around the joint, and introducing sealant into the cavity through said fill tube.

Z. The process of claim 1, wherein said excavation has an opening less than one square foot in horizontal area in the paving at grade, and wherein the steps are performed from the surface of the excavation.

3. The process of claim 1, in which the coiled metallic band is secured in tightened position by a laterally disposed buckle having a radially protruding locking bolt and said bolt is tightened by a wrench which extends downwardly into the excavation and which is operable by a rotatable handle from above the surface of the excavation and has a transversely extending socket engageable with said bolt.

4. The process of sealing a bell and spigot joint in a pipe line buried beneath a paved area, which comprises breaking paving in an area less than one square foot at grade at a position directly above the bell and spigot joint, excavating from the opening in the paving to and around the bell and spigot joint, blast cleaning the face of the bell and the adjoining spigot, inserting and attaching around the bell and spigot joint a mold to create a mold cavity adjoining the face ofthe bell and around the spigot, securing the mold to the joint by banding the outside of the mold over the bell and spigot, forcing sealant under pressure into the cavity of 4the mold, leaving the mold in place, and iilling the excavation.

5. The process of sealing a bell and spigot joint in a pipe main at the bottom of an earth excavation with a circumferentially overlapping exible resilient mold having a lill tube and a helically wound tensile spring adapted to be connected to said till tube for holding said mold in wrapped engagement with said joint comprising the steps of blast cleaning the face of the bell and the adjoining spigot, using a longhandled tool to grasp the fill tube and lower the mold into the excavation about the joint, allowing the mold to return to its natural circular position about the joint, grasping said spring with a longhandled tool to connect said spring to said lill tube, tapping the mold with a longhandled tool longitudinally into abutting relationship against the bell, applying a coiled band around the joint, tightening the band to tightly squeeze the mold about the bell and spigot, whereby the mold forms an annular cavity around the joint, and introducing sealant under pressure intoy the cavity through said fil] tube.

6. The process of claim 5, wherein said sealant is a partially hardenable exible sealant and remains pressurized in said mold cavity until it has hardened.

7. The process of claim 6, wherein excavation is made larger at the base in the area of the joint than in the paving at the grade.

8. The process of claim 5, in which the coiled band is secured in tightened position by a laterally disposed buckle having a radially protruding locking bolt and said bolt is tightened by a Wrench which extends downwardly into the excavation and which is operable by a rotatable handle from above the surface of the excavation and has a transversely extending socket engageable with said bolt.

9. The process of sealing a bell and spigot joint in a pipe line buried beneath a paved area, which comprises breaking paving in an area less than one square foot at grade at a position directly above the bell and spigot joint, excavating from the opening in the paving to and around the bell and spigot joint, blast cleaning the face of the bell and the adjoining spigot, inserting and -attaching around the bell and spigot joint a rnold to create a completely annular mold cavity adjoining the face of the bell and around the spigot, securing the mold to the joint by banding the outside of the mold over the bell and spigot, forcing sealant under pressure into the cavity of the mold, leaving the mold in place with the sealant pressurized, and iillin g the excavation.

References Cited UNITED STATES PATENTS 943,558 l2/1909 Milam 285-294 1,462,077 7/1923 Weston 25-127 2,163,261 6/1939 Norton 13S-97 2,463,231 3/1949 Wyatt 264-263 X 3,265,782 8/1966 Rosengarten 264-32 3,228,712 l/l966 Hausmann et al. 25-127 3,260,280 7/1966 Buczala et al. 13S-97 ROBERT F. WHITE, Primary Examiner.

T. I. CARVS, Assistant Examiner.

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