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We have seen what is pig, pigging, types of pigging in the previous post.
Now here we are going to see PIG TRAP Design, Operating and Selection.
1 Design Parameters
2 Operating Method
As part of a complete pigging system, pig traps allow pigs to be inserted into and
removed from a pipeline which is to undergo a pigging program and which is likely to
be under pressure.
a. Pressure Gauge
c. Pressure Relief
e. Pig Signaller
f. Kicker Valve (Launcher) Bypass Valve (Receiver)
g. Mainline Bypass Valve
h. Mainline Trap Valve
i. Quick Release Closure
Fig 1. Typical Trap Configuration (Horizontal Launcher/Receiver)
Pig traps can be, and frequently are, referred to by
different names some of which may be no more
than alternatives and some which more accurately
describe the trap’s function. Popular alternatives
are: Launchers, Receivers, Scraper Traps, Scraper
Barrels, Universal Traps, Bi-Directional Traps,
Sphere Traps. The name may also describe the
orientation of the trap, giving a clue to its intended
purpose: Vertical, Horizontal, Inclined, Declined,
If a pipeline is to be pigged, launching and
receiving facilities (pig traps) must be provided.
For large diameter pipelines this results in pig traps
up to 56” (nominal pipeline diameter) weighing
many tonnes and represent a significant capital
investment. Any company that manufactures this
type of equipment requires the scope and
experience to do so and must possess excellent engineering resources, both in its
equipment and its staff Entrusting the design of these systems to non-specialists
armed with a few proprietary catalogues is a short-sighted and all too frequent shortlived
Pipeline Engineering’s technical engineers have many years of experience in pig trap
design and are fully conversant with all the major design codes and make full use of
state-of-the-art CAD facilities. All welders are fully qualified to both American and
British welding codes while the Inspection and Quality Assurance systems ensure
control at every stage of the manufacturing process from order to delivery.