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Section VIII – Application Guide
1.0
Recommended
Applications
1.0 RECOMMENDED APPLICATIONS
The PIG-SIG V uses opposing magnets across a
solid plug body web instead of a rotating shaft with
(dynamic) O-ring seal. The static O-ring on the
outside diameter of the plug body is the only seal
needed to prevent pipeline product leakage. In the
standard PIG-SIG V model, the magnet in the lower
plug body (trigger) housing is exposed to pipeline
fluids which can result in attraction of magnetic debris
(hot tapping filings and corrosion scale or powders).
While the trigger cavity is “self-flushing,” build-up of a
significant amount of magnetic debris can limit the
stroke of the trigger and/or reduce the effectiveness
of the magnet. Liquid or relatively high pressure gas,
combined with turbulence due to high flow rate can
kick up heavy amounts of magnetic particulates.
Heavy wax pushed into the PIG-SIG V trigger cavity
due to infrequent pigging may also create more
debris volume than can be effectively flushed out,
resulting in reduced trigger stroke (failure to trip)
and/or resistance to returning to the normal state
(which may prevent an electrical switch from
releasing).
1.1 Standard PIG-SIG V
Standard PIG-SIG V models are recommended for
pipelines with minimal amounts of heavy wax present
(especially from infrequent pigging). These include
pipelines with relatively low density, low viscosity
fluids (gas or refined products), and relatively low
velocity, with any concentration of ferrous and non-
ferrous particulates (corrosion products, filings,
chips). Not recommended for high-viscosity oil with
heavy wax.
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