Pig Tracking Systems Overview - SPY PIG TRACKING SYSTEMS Operating Instructions Manual

pig tracking systems
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SPY Inspection Equipment manufactures a complete line of portable
®
and "On-Pipe" pig tracking and locating systems. Pig Tracking refers
to monitoring the passage of a pig as it moves past prescribed and
monitored points along the pipeline. Pig Locating refers to pinpointing
a pig that has become stuck or lost in a given pipeline or pipe manifold
system on land or at sea.
Unfortunately, carbon steel pipe acts as an ideal electromagnetic shield,
which limits the possible methods of transmitting a signal through the
pipe wall to a sensor. The common methods used to sense the passage
of a pig or attempt to locate it are: mechanical; radioactive; acoustic;
magnetic; and electromagnetic.
Mechanical systems have several drawbacks. They are invasive into the
line, which makes them a potential environmental and safety hazard. They
are subject to contamination by materials in the pipe, which can prevent
them from operating correctly. They are also subject to mechanical wear
and damage, which will prevent them from operating properly.
Radioactive systems have two main drawbacks. One of which, the
radioactive nature of the transmitting device itself makes people
extremely skittish in regards to using it. The second is that the transmit-
ting distance is very limited which makes it primarily usable only when
the "outside-the-pipe" sensor is directly attached to the pipe.
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