Note: Descriptions are shown in the official language in which they were submitted.
CA 02790221 2012-09-18
Pig Receiver Assembly
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of U.S.
Application Serial No.
12/754,518 filed on April 5, 2010, which is herein incorporated by reference
in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED
RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
Field of the Invention
[0003] This invention relates to the field of pipeline maintenance and more
specifically to the
field of using pipeline pigs for pipeline maintenance and new construction.
Background of the Invention
[0004] Pipeline pigs are conventionally used in the maintenance of pipelines.
Pipeline pigs are
typically inserted into a pig launcher. Pressure may then be added that pushes
the pipeline pig
along the pipeline until it reaches a pig receiver for removal from the
pipeline. The pipeline pigs
are commonly used to remove foreign material that may be in the line during
construction of new
pipelines. The pipeline pigs may also be used to make sure the pipeline has
not become dented or
wrinkled during bending or laying as well as also used to check for the
ovalness of the pipeline.
Further uses of the pipeline pigs may include removing water from pipelines
after hydrostatic tests.
[0005] Drawbacks to conventional pig receivers include harm to the
environment. For instance,
matter removed from the pipelines may not be properly contained. Additional
drawbacks to
conventional pig receivers include downtime in launching new pipeline pigs
when other pipeline
pigs are being removed from the pipeline.
[0006] Consequently, there is a need for an improved pig receiver that allows
pipeline pigs to be
continually launched and received in pipelines. Further needs include improved
pig receivers that
facilitate environmental concerns.
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BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS
[0007] These and other needs in the art are addressed in one embodiment by a
pig receiver that
includes a pig receiver unit. The pig receiver also includes a pig gate valve
assembly disposed on
the pig receiving unit. The pig gate valve assembly includes a gate valve. The
pig gate valve
assembly also includes a first actuator and a second actuator. The pig gate
valve assembly further
includes a cylinder guide. In addition, the pig gate valve assembly includes a
tie bar. Actuation of
the tie bar actuates the gate valve. An end of the tie bar is attached to the
first actuator, and an
opposing end of the tie bar is attached to the second actuator. The pig
receiver also includes a
pressure equalization system. The pressure equalization system adjusts the
pressure downstream
of the gate valve when the gate valve is in a closed position.
[0008] In addition, these and other needs in the art are addressed in an
embodiment by a method
for retrieving a pipeline pig. The method includes allowing the pipeline pig
to run into a pig
receiver. The pig receiver includes a pig receiver unit comprising a retrieval
door. The pig
receiver also includes a pig gate valve assembly disposed on the pig receiving
unit. The pig gate
valve assembly includes a gate valve. The gate valve is in an open position.
In addition, the pig
gate valve assembly includes a first actuator and a second actuator. The pig
gate valve assembly
also includes a cylinder guide. The pig gate valve assembly further includes a
tie bar. Actuation of
the tie bar actuates the gate valve. An end of the tie bar is attached to the
first actuator, and an
opposing end of the tie bar is attached to the second actuator. The pig
receiver also includes a
pressure equalization system. The pressure equalization system adjusts the
pressure downstream
of the gate valve when the gate valve is in a closed position. The method also
includes actuating
the pig gate valve assembly to move the gate valve to a closed position. In
addition, the method
includes opening the retrieval door. The method further includes retrieving
the pig.
[0009] The foregoing has outlined rather broadly the features and technical
advantages of the
present invention in order that the detailed description of the invention that
follows may be better
understood. Additional features and advantages of the invention will be
described hereinafter that
form the subject of the claims of the invention. It should be appreciated by
those skilled in the art
that the conception and the specific embodiments disclosed may be readily
utilized as a basis for
modifying or designing other embodiments for carrying out the same purposes of
the present
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invention. It should also be realized by those skilled in the art that such
equivalent embodiments
do not depart from the spirit and scope of the invention as set forth in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a detailed description of the preferred embodiments of the
invention, reference will
now be made to the accompanying drawings in which:
[0011] Figure 1 illustrates a pig receiver, pig receiving unit, and pig gate
valve assembly;
[0012] Figure 2 illustrates an actuation system; and
[0013] Figure 3 illustrates a pig receiver having a pressure equalization
system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Figure 1 illustrates pig receiver 5 having pig receiver unit 10,
support 15, and pig gate
valve assembly 20. Pig gate valve assembly 20 is secured to pig receiver unit
10 and allows pig
receiver unit 10 to receive pigs (not illustrated) while additional pig or
pigs may continue to
progress through a pipeline (not illustrated). In an embodiment, pig receiver
5 is attached to the
pipeline at pipeline contact end 165. The pigs enter pig receiver 5 at
pipeline contact end 165.
Pipeline contact end 165 may be attached to the pipeline by any suitable
means.
[0015] Pig receiver unit 10 has any configuration suitable for facilitating
passage of pigs
therethrough. In an embodiment as illustrated in Figure 1, pig receiver unit
10 has the typical
configuration of a pipeline (e.g., substantially cylindrically shaped). In
some embodiments as
illustrated in Figure 1, pig receiver unit 10 has an enlarged diameter on pig
retrieval end 170,
which is the end of pig receiver unit 10 longitudinally distal from pipeline
contact end 165.
Without being limited by theory, pig retrieval end 170 has an enlarged
diameter because the
enlarged diameter facilitates removing pigs from pig receiver unit 10. Pig
receiver unit 10 has
retrieval door 175. Retrieval door 175 is an openable and closeable door. In
embodiments in
which retrieval door 175 is open, pigs may be retrieved from pig receiver unit
10.
[0016] In some embodiments as illustrated in Figure 1, pig receiver unit 10
also has take-off 90.
In embodiments, take-off 90 allows for product or other material in pig
receiver unit 10 to be
removed. In an embodiment as illustrated in Figure 1, take-off 90 is disposed
on the surface of pig
receiver unit 10 at a location between gate valve 25 and pipeline contact end
165. In some
embodiments, pig receiver unit 10 has more than one take-off 90. In other
embodiments as
illustrated in Figure 1, pig receiver unit 10 also has fastening means 130.
Fastening means 130
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include any means for fastening pig receiver 5 to a transportation means for
transporting pig
receiver 5 and/or for alignment of pig receiver 5 with a pipeline. In an
embodiment as illustrated in
Figure 1, fastening means 130 is an eye fastener.
[0017]
As shown in Figure 1, pig gate valve assembly 20 includes gate valve 25,
actuators 40
and 45, and cylinder guide 60. Gate valve 25 refers to an openable/closeable
valve comprising a
round, rectangular, or the like gate/wedge. Gate valve 25 includes gate valve
seat 35. When gate
valve 25 is in the closed position, gate valve seat 35 provides a seal that
facilitates prevention of
liquid leaking around gate valve 25. Gate valve 25 is attached to rod 65. In
an embodiment as
illustrated, gate valve 25 is attached to rod 65 on the longitudinal end of
gate valve 25 distal to gate
valve seat 35. Rod 65 is attached to tie bar 70. In an embodiment as
illustrated, rod 65 is attached
to tie bar 70 on the longitudinal end of rod 65 distal to gate valve 25. It is
to be understood that rod
65 is shown in Figure 1 by dashed lines for illustrated purposes only to show
its location as rod 65
is not visible as shown from the side view of Figure 1 (i.e., it is disposed
within gate housing 30).
Rod 65 and gate valve 25 are longitudinally moveable through the interior of
gate housing 30. In
an embodiment, gate housing 30 is secured to pig receiver unit 10. Gate
housing 30 may be
secured to pig receiver unit 10 by any suitable means. Cylinder guide 60 is
secured to gate housing
30. Cylinder guide 60 extends longitudinally upward from gate housing 30. Pig
gate valve
assembly 20 also includes tie bar 70 and actuator support 75. Tie bar 70 and
actuator support 75
are disposed on opposing ends of actuators 40, 45 from each other. Tie bar 70
has tie bar end 180
and tie bar end 185 on opposing longitudinal ends, and actuator support 75 has
support end 190
and support end 195 on opposing longitudinal ends. Tie bar 70 is attached to
both actuator 40 and
actuator 45. Actuator 40 includes cylinder rod 220, and actuator 45 includes
cylinder rod 150. In
an embodiment, tie bar end 180 is attached to cylinder rod 220 at cylinder
longitudinal end 200,
and tie bar end 185 is attached to cylinder rod 150 at cylinder longitudinal
end 205. In
embodiments, tie bar ends 180, 185 may be attached to cylinder rods 220, 150,
respectively, by any
suitable means. Support ends 190, 195 may be secured to cylinder longitudinal
ends 210, 215 by
any suitable means. In an embodiment, cylinder longitudinal ends 210, 215 are
disposed upon
support ends 190, 195, with actuator support 75 providing physical support to
actuators 40, 45. Tie
bar 70 has tie bar opening 225 through which cylinder guide 60 may
longitudinally pass
therethrough. In an embodiment, actuator support 75 has support opening 230
through which a
portion of gate housing 30 is disposed.
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[0018] Actuators 40, 45 may include any suitable type of actuator for
actuating opening and
closing of gate valve 25. In embodiments, actuators 40, 45 are actuated by air
and/or liquid (e.g.,
water). In embodiments, actuators 40, 45 are actuated by air. Actuators 40, 45
may have any
suitable configuration for actuation of gate valve 25. In embodiments as
illustrated in Figure 1,
actuators 40, 45 are cylindrical actuators. Actuators 40, 45 may be operated
by any suitable means.
Figure 2 illustrates an embodiment of manual operation of actuators 40, 45. In
an embodiment as
illustrated, actuation lever 140 is operated between open and closed
positions. In embodiments,
the open position actuates actuators 40, 45, and the closed position stops
their action. The
actuating air and/or liquid are supplied from inlet 155 to actuators 40, 45
via actuation lines 145.
The return actuating air and/or liquid may be exhausted via outlet 160.
Actuation lever 140 may be
disposed at any suitable location on pig receiver 5. In an embodiment,
actuation lever 140 is
disposed on a side of pig receiver 5. Without limitation, embodiments with two
actuators 40, 45
facilitate prevention of bending of rod 65. In an embodiment, actuation of
actuators 40, 45
includes actuation of cylinder rods 150, 220 either in an upward or downward
direction (i.e., in
relation to pig receiver unit 10).
[00191 In embodiments, gate valve 25 is moveable between open and closed
positions. To move
gate valve 25 to an open position from the closed position shown in Figure 1,
actuation lever 140 is
moved to the open position. The actuating air and/or liquid flows through
actuation lines 145 to
actuators 40, 45 thereby actuating actuators 40, 45 to move cylinder rods 150,
220 upwards.
Upward movement of cylinder rods 150, 220 causes upward movement of rod 65
(via tie bar 70)
and thereby rod 65 pulls gate valve 25 upward. Tie bar 70 moves upward along
with cylinder rods
150, 220. The vertical movement of cylinder rods 150, 220 is guided by tie bar
70 having cylinder
guide 60 pass therethrough. Cylinder guide 60 facilitates tie bar 70 moving in
a substantially
vertical direction. It is to be understood that cylinder guide 60 and gate
housing 30 are not moving.
Cylinder rods 150, 220 move upward until gate valve 25 is in an open position.
To close gate
valve 25, actuation lever 140 is moved to the closed position. Actuators 40,
45 then move cylinder
rods 150, 220 downward with rod 65 pushing gate valve 25 downward into pig
receiver unit 10
until gate valve 25 is in a closed position (i.e., substantially no fluid
flows around gate valve 25).
In an embodiment, the open position of gate valve 25 is in a fully open
position with gate valve 25
not restricting any fluid flow within pig receiver unit 10.
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[0020] In embodiments as shown in Figure 1, pig receiver 5 also includes
supports 15. Supports
15 may include any size and configuration suitable for supporting the weight
of pig receiver unit
10. Pig receiver 5 is not limited to two supports 15 but in alternative
embodiments may include
one support 15 or more than two supports 15. In some embodiments, pig receiver
unit 10 includes
drain 95.
[0021] As illustrated in Figures 1 and 2, an embodiment of operation of pig
receiver 5 includes
pig receiver 5 attached to a pipeline (not illustrated). A pig (not
illustrated) is progressing through
the pipeline. At this instance, no pig is disposed within pig receiver 5. With
the pig progressing
through the pipeline, gate valve 25 is in the open position, and retrieval
door 175 is closed. In
some embodiments, pig receiver unit 10 has exhaust valves 100, 115. Exhaust
valve 100 is
disposed on pig receiver unit 10 between pig gate valve assembly 20 and
pipeline contact end 165.
In an embodiment, exhaust valve 100 is located proximate to pig gate valve
assembly 20. Exhaust
valve 115 is disposed between pig gate valve assembly 20 and pig retrieval end
170. In an
embodiment, exhaust valve 115 is disposed proximate retrieval door 175.
Exhaust valves 100, 115
may be any type of pressure relief valves suitable for exhausting pressure
from pig receiver unit
10. In embodiments, exhausts valves 100, 115 are used to regulate and maintain
a constant
pressure in pig receiver unit 10. In some embodiments as illustrated, exhaust
valves 100, 115 have
exhaust silencers 105, 120, respectively. In embodiments as illustrated, a
pressure gauge 80
measures the pressure of pig receiver unit 10 upstream of pig gate valve
assembly 20. In an
embodiment, pressure gauge 80 is disposed proximate exhaust valve 100.
Additionally, in
embodiments as illustrated, a pressure gauge 85 measures the pressure of pig
receiver unit 10
downstream of pig gate valve assembly 20. In an embodiment, pressure gauge 85
is disposed
proximate exhaust valve 115. When the pig passes pig gate valve assembly 20,
the pig gate valve
assembly 20 is actuated with actuators 40, 45 moving cylinder rods 150, 220
downward and
pushing gate valve 25 into the closed position by cylinder rods 150, 220
pushing rod 65 downward.
With gate valve 25 in the closed position, additional pigs may run in the
pipeline. In embodiments,
both exhausts valves 100, 115 remain open. In an embodiment, pressure gauge 85
is monitored,
and if it shows a desired pressure, then retrieval door 175 is opened, and the
pig is removed. In an
embodiment as illustrated, exhaust valve 115 has lever 125. In an embodiment,
lever 125 is
disposed to provide an end of lever 125 sufficiently in front of retrieval
door 175 to prevent
opening of retrieval door 175 until the pressure in pig retrieval end 170 is
at a desired pressure.
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When at a desired pressure, lever 125 is actuated (and the blocking end of
lever 125 is no longer
preventing opening of retrieval door 175), and retrieval door 175 is opened
with the pig then being
removed. With the pig removed, retrieval door 175 is closed, and pig gate
valve assembly 20 is
actuated to move gate valve 25 up to the open position. The next pig is then
run through pig
receiver 5, and the process may continue as desired.
[0022] Figure 3 illustrates an embodiment of pig receiver 5 having a pressure
equalization
system 250. Pressure equalization system 250 has pressure equalization valve
235 and pressure
line 240. Pressure equalization system 250 facilitates adjusting the pressure
in pig receiver unit 10
downstream of gate valve 25. Pressure line 240 is connected to pig receiver
unit 10 on each side of
gate valve 25 at downstream pressure connection 255 and upstream pressure
connection 260,
respectively. As illustrated, downstream pressure connection 255 is connected
to pig receiver unit
downstream of gate valve 25 at a suitable location between gate valve 25 and
retrieval door 175.
In an embodiment, downstream pressure connection 255 is disposed at a suitable
location between
fastening means 130 and gate valve 25. Upstream pressure connection 260 is
connected to pig
receiver unit 10 upstream of gate valve 25 at a suitable location between gate
valve 25 and pipeline
contact end 165. In an embodiment, upstream pressure connection 260 is
disposed at a suitable
location between gate valve 25 and fastening means 130. Pressure line 240 may
be any line
suitable for use with a pipeline. Pressure equalization valve 235 controls the
pressure flow through
pressure line 240. Pressure equalization valve 235 may be any type of valve
suitable for use with a
pig receiver. For instance, in an embodiment, pressure equalization valve 235
is a ball valve.
Pressure equalization valve 235 may be disposed at any suitable location on
pressure line 240. In
an embodiment, pressure equalization valve 235 is disposed about equidistant
between
downstream pressure connection 255 and upstream pressure connection 260. In
embodiments,
pressure equalization valve 235 is disposed proximate to gate valve 25. In
some embodiments as
illustrated, downstream pressure connection 255 and/or upstream pressure
connection 260 have a
muffler 245.
[0023] As illustrated in Figure 3, an embodiment of operation of pressure
equalization system
250 includes closing gate valve 25 or in which gate valve 25 is closed. In
such an embodiment,
pressure equalization valve 235 is in a closed position. In an embodiment,
pressure equalization
valve 235 is in a closed position when gate valve 25 is closed. In some
embodiments, pressure
equalization valve 235 is opened when gate valve 25 is in a closed position or
when gate valve 25
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is being closed. With gate valve 25 in a closed position and pressure
equalization valve 235 open,
the pressure downstream of gate valve 25 is adjusted via pressure line 240 by
the pressure from
upstream of gate valve 25. In an embodiment, the pressure downstream is
adjusted to be about
equal with the pressure upstream. In some embodiments, the pressure upstream
and downstream
of gate valve 25 is about equalized via pressure line 240.
[0024] It is to be understood that pig gate valve assembly 20 is not limited
to two actuators
(actuators 40, 45). In alternative embodiments (not illustrated), pig gate
valve assembly 20 has one
actuator. In other alternative embodiments (not illustrated), pig gate valve
assembly 20 has more
than two actuators.
[0025] It is to be further understood that tie bar 70 and cylinder guide 60
facilitate cylinder rods
150, 220 to move substantially parallel in relation to each other.
[0026] Although the present invention and its advantages have been described
in detail, it should
be understood that various changes, substitutions and alterations may be made
herein without
departing from the spirit and scope of the invention as defined by the
appended claims.
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