Weldless pipe repair apparatus and method

A pipeline connector and repair system for sealingly connecting the ends of first and second pipes together without welding or bolting. First and second connectors are provided at each end of a pipe joint and are inserted between the ends of the first and second pipes to be connected, the connectors are extended outwardly for enclosing the ends of the first and second pipes, and dual slip means and dual seal means in each of the connectors are hydraulically set for making the repair.

BACKGROUND OF THE INVENTION 
Pipeline repairs are becoming more common as existing pipe networks age. In 
particular, a need exists in underwater pipeline repairs for a simple, 
reliable weld-free mechanical connector. The present invention is directed 
to a connector and repair system that does not require welding, and does 
not require flange bolting. Instead, the present invention uses hydraulic 
cylinders and pistons to actuate slip mechanisms and seals as well as 
longitudinally positioning the connectors. 
SUMMARY 
The present invention is directed to a pipeline connector for sealingly 
connecting the ends of first and second pipes together and includes a 
housing having a bore therethrough and having first and second ends for 
receiving the first and second pipes, respectively. First, second, third 
and fourth oppositely movable pistons are provided in the housing. First 
seal means and first slip means are provided in the housing actuated by 
the first and second pistons, respectively, for engaging the first pipe. 
Third and fourth oppositely movable pistons are provided in the housing 
and second slip means and second seal means are provided in the housing 
actuated by the third and fourth pistons, respectively, for engaging the 
second pipe. 
Still a further object of the present invention is wherein coacting locking 
means are provided between the housing and each of the first and fourth 
pistons for engaging when the first and second seal means are set thereby 
providing a load limiting device preventing the seals from becoming 
over-stressed. 
A further object is the provision of coacting locking means between the 
housing and each of the second and third pistons for engaging when the 
first and second slips means and set thereby providing permanent and 
irreversible engagement of the slip means into first and second pipes. 
Still a further object of the present invention is the provision of piston 
and cylinder means connected to the housing and one of the pipes for 
longitudinally moving the housing relative to the pipes. 
Yet a still further object of the present invention is the provision of a 
pipe engaging support connected to one end of the housing for engaging one 
of the pipes for aligning and supporting the housing. Preferably, the pipe 
engaging support is arcuately shaped. 
Yet a still further object of the present invention is wherein one end of 
the housing includes an interior surface surrounding the bore and having 
first and second sections tapered inwardly for aligning a pipe inserted 
into the one end. Preferably, the first and second sections are separated 
by a uniform section and preferably the tapered section nearest the one 
end has a greater taper than the other tapered section. 
Still a further object of the present invention is the provision of a 
pipeline connector system for inserting into spaced ends of first and 
second pipes for sealingly connecting said pipes together. The system 
includes first and second housings each having a bore therethrough, and 
including first and second joints positioned in one end of each of the 
housings, respectively, and said joints are adapted to be connected 
together. Each of the housings include two hydraulically actuated slip 
means and two hydraulically actuated seal means. First piston and cylinder 
piston means are connected between the first housing and the first joint 
for longitudinally moving the first housing relative to the first joint, 
and second piston and cylinder means are connected to the second housing 
and the second joint for longitudinally moving the second housing relative 
to the second joint. 
Still a further object of the present invention is the method of sealingly 
connecting the spaced ends of first and second pipes together with a pipe 
joint having a connector at each end of the pipe joint and longitudinally 
movable thereon in which each connector includes dual slip means and dual 
seal means. The method includes retracting the connectors towards the 
center of the pipe joint, inserting the pipe joint between the ends of the 
first and second pipes, extending the connectors outwardly for enclosing 
the end of the first pipe in one connector and enclosing the end of the 
second pipe in the other connector, and hydraulically setting the dual 
slip means and dual seal means in each connector for gripping and sealing 
one of the slip means and one of the seal means against each end of the 
pipe joint and the ends of the first and second pipes.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As the present invention is particularly useful in replacing defective 
sections of underwater pipelines, the present invention will be described 
in such application which utilizes dual connectors of the present 
invention. It is to be understood that in other applications, a single 
connector may be used. 
Referring now to the drawings, and particularly to FIGS. 1 and 5, the 
reference numeral 10 generally indicates the pipeline repair system of the 
present invention for inserting into spaced ends of first pipe 12 and 
second pipe 14 positioned underwater in which a defective section of the 
pipeline has been removed. The repair system generally includes a first 
connector 16, a second connector 18, which is a mirror image of the first 
connector 16, a first pup joint 20 connected to the first connector 16, a 
second pup joint 22 connected to the connector 18 and a spool piece 24 
connected to the pup joints 20 and 22. The pup joints 20 and 22 and the 
spool piece 24 form a pipe joint of substantially a length to fit between 
the ends of the first pipe 12 and second pipe 14 of FIG. 5. Since the 
connectors 16 and 18 are mirror images of each other, only the connector 
18, which is shown in greater detail of FIG. 2 will be described in detail 
and corresponding parts of connector 16 will be similarly numbered with 
the addition of the suffix "a". The connector 18 includes a housing 26 
having a bore 28 therethrough and includes a first end 30 and a second end 
32 for receiving first and second pipes, respectively, and as shown here 
the pup joint 22 and the pipe 14 (FIG. 5). 
A first piston 34 and a second oppositely movable piston 36 are provided in 
the housing 26. Spaced from the first and second pistons 34 and 36 are 
third piston 38 and oppositely movable piston 40 in the housing 26. All of 
the pistons 34, 36, 38 and 40 are actuated by providing hydraulic fluid to 
a hydraulic connector 42. First slip means 44 and second seal means 46 are 
provided in the housing and are actuated by the second piston 36 and first 
piston 34, respectively, for engaging and sealing against a first pipe, 
here the pup joint 22. Second slip means 48 and second seal means 50 are 
provided in the housing 26 and are actuated by the third and fourth 
pistons 38 and 40, respectively, for engaging a second pipe, such as 14. 
The slip means 44 and 48 each include conventional cone segments with 
teeth 45 and wedges 47. The seal means 46 and 50 may be any suitable seal 
such as an elastomeric seal 49 with anti-extrusion devices 51 on either 
side. 
Coacting locking means are provided between the housing 26 and each of the 
pistons 34, 36, 38 and 40, such as locking rings 52, 54, 56 and 58 which 
lock in grooves 53, 55, 57 and 59, respectively. The locking rings 52 and 
58 provide a load limiting device preventing the elastomeric seals 49 from 
becoming over-stressed. The locking rings 54 and 56 lock the slips 44 and 
48 in place and prevent their unloading. One or more positioning hydraulic 
actuators 60 are provided connected to the housing 26 and one of the 
pipes, here the pup joint 22, for longitudinally moving the housing 26 
relative to the pup joint 22 and the pipe 14. Thus, the housing 26 can be 
positioned in a retracted position as shown in FIGS. 1 and 2 for insertion 
into the space between the pipes 12 and 14 of FIG. 5, but can be placed in 
an extended position as best seen in FIGS. 3 and 4 for ensuring that the 
first slip means 44 and the first seal means 46 engage the first pipe, 
here the pup joint 22, while the second slip means 48 and the second seal 
means 50 engage the pipe 14. The actuators 60 and 60a are connected to and 
actuated by hydraulic connectors 63 and 63a, respectively. 
Referring now to FIGS. 1-4, a pipe engaging support or visor 62 and 62a are 
connected to one end of the housing of the connectors 18 and 16, 
respectively, for engaging a pipe for aligning and supporting the housing 
with the pipe, as best seen in FIGS. 6 and 7 as will be more fully 
discussed hereinafter. In addition, one end of the housing 26 (FIG. 2) 
includes an interior surface surrounding the bore 28 having a first 64 and 
a second 66 tapered section which are tapered inwardly for the purpose of 
aligning a pipe inserted into the end 32. That is, the pipes 12 and 14 
(FIG. 5) may not be fully aligned and as will be more fully discussed 
hereinafter, the tapered sections 64 and 66 assist in aligning a pipe that 
is inserted in the end 32. 
The method of utilizing the pipeline repair system 10 of FIGS. 1-4 for 
replacing a defective portion of a pipeline is best seen by referring to 
FIGS. 5-9. In FIG. 5, the defective portion of the pipeline has been 
removed and the waterbed 15 below the pipeline is removed, and the ends of 
the pipes 12 and 14 have had all coatings removed and are cleaned. 
However, the ends of the pipe 12 and 14 are not required to be machined as 
the connectors 16 and 18 are designed to attach and seal against 
unmachined rough pipe ends. As best seen in FIG. 5, the system 10 is 
prepared with the proper length of spool piece 24 welded to the pup joints 
20 and 22 and the connectors 16 and 18 are placed in a retracted position 
such as shown in FIGS. 1 and 2. The system 10 is lowered into the water by 
a line 17 into the space between the ends of the pipes 12 and 14. As best 
seen in FIG. 6, the system 12 is lowered as a unit and may be guided by 
any suitable means such as a conventional ROV 70 (remote operating 
vehicle) to one of the pipes, such as 12. Preferably, the system 10 is 
inclined, such as 20.degree., to ensure that the opposite end remains 
elevated above the work site while the connector 16 is being lowered onto 
the pipe 12 for preventing excessive sand and silt from entering the 
connector 18. The pipe engaging support or visor 62a is set down on top of 
the pipe 12 thereby aligning and supporting the connector 16 from the pipe 
12. Further lowering of the system 10 brings the pipe engaging support 62 
down on top of the pipe 14. This lands the system 10 onto and supported 
between the pipes 12 and 14, as best seen in FIG. 7. With the system 10 in 
place, the ROV 70, or other means such as a diver, makes a hydraulic 
connection to the connector 63 on the connector 18 and as best seen in 
FIG. 8 actuates the positioning actuators 60 to extend the connector 18 to 
enclose the pipe 14 into the connector 18, as best seen in FIG. 4. The ROV 
70 will then move to the hydraulic connection 63a on the connector 16 to 
actuate the positioning hydraulic actuators 60a to similarly move the 
connector 16 over the pipe 12. Thus, as best seen in FIG. 9, with the ends 
of the pipes 12 and 14 positioned inside of the connectors 16 and 18, the 
ROV, or other means, makes a hydraulic connection with connector 42 in the 
connector 18 for actuating the pistons 34, 36, 38 and 40, as best seen in 
FIG. 4, thereby setting the slips 44 and the seal means 46 against the 
exterior of the pup joint 22 and gripping and sealing the slip means 48 
and the seal means 50 against the pipe 14. Thereafter, the ROV moves to 
the other end of the system 10 to the hydraulic connection 42a to 
similarly actuate the connector 16 to grip and seal against the pup joint 
20 and the pipe 12. 
In addition, the lock rings 52, 54, 56 and 58 will engage the pistons 34, 
36, 38 and 40, respectively, for limiting the load applied to the seals 48 
and 50 and preventing their extrusion and for locking the slips fully in 
place and preventing their release. As a backup, if desired, a check valve 
can be used in the hydraulic lines to effect a fluid lock or epoxy can be 
substituted for hydraulic oil. Referring now to FIG. 4, another hydraulic 
connector 72 is provided which is connected to test lines for applying 
hydraulic pressure to the housing of the connectors 16 and 18 between the 
seals 46 and 64 and between 65 and 50 whereby the repair can be tested and 
verified to provide positive information on the integrity of the repair. 
While the foregoing description of the invention has been described in 
connection with a system having two connectors, it is to be understood 
that in some repair situations, a single connector can be connected to one 
pipe, such as by weld or a flange, and be extended to connect to a second 
pipe, or even used as an outside coupling between two pipes. 
Referring now to FIG. 10, a fragmentary cross-sectional view of the double 
tapered end of each of the housings of the connectors 16 and 18 is shown 
for receiving the pipes 12 and 14, respectively. The preferred numerical 
values of the sizes and shapes of the double tapered sections 64 and 66 
which are separated by uniform section 68 is best seen. The purpose of the 
double tapered section is to align an incoming pipe. That is, the pipes 12 
and 14 may not be fully aligned. Therefore, the purpose of the double 
tapered section is to align the pipes 12 and 14 and to allow the 
connectors to enclose the pipe ends so that the various slip means and 
seal means will more completely and fully engage, grip, and seal on the 
pipes 12 and 14. 
Referring now to FIG. 11A, the end 32 of the housing 26 of the connector 18 
is shown moving relative to the pipe 14 and the misalignment of the pipe 
14 relative to the longitudinal axis 27 is exaggerated. It is to be noted 
that the tapered section 64 has a greater inward taper than the second 
tapered section 66 for providing an enlarged receiving opening. For 
example only, the taper of section 64 may be 5.degree. while the taper of 
the second section 66 may be 3.degree.. In FIG. 11A, the enclosure of pipe 
14 pushes its end against the first tapered section 64 and its side 
against the end 32 of the housing 26. This creates a torque tending to 
bring the pipe 14 into alignment with the axis 27 of the housing 26. The 
length, diameter, and amount of taper, as set forth in FIG. 10, relative 
to diameter D of the inserted pipe 14 is selected to obtain the desirable 
alignment. For instance, the longitudinal length of tapered section 64 is 
greater than the longitudinal length of the uniform section 68 and the 
second tapered section 66 and has a larger bore for more easily engaging 
the pipe 14 and applying torsional forces to properly direct its end. The 
uniform section 68 is larger than the nominal bore size of housing 26 and 
then allows the entry pipe 14 to move further into the housing 26 and has 
a length to provide a geometry to to provide a moment arm to align pipe 
14. The second tapered section 66 performs the function of receiving the 
aligned pipe 14. The geometry of the housing 26 provides contact points 
between the pipe 14 and the housing 26 which are no less than one D of the 
pipe 14 apart. 
The present invention, therefore, is well adapted to carry out the objects 
and attain the ends and advantages mentioned as well as others inherent 
therein. While a presently preferred embodiment of the invention has been 
given for the purpose of disclosure, numerous changes in the details of 
construction, and steps of the process will be readily apparent to those 
skilled in the art, and which are encompassed within the spirit of the 
invention and the scope of the appended claims.