As part of the Nordstream pipeline
project, Netherlocks has provided an
electro-mechanical control cabinet in
combination with an interlocking
system for the pigging process. A
custom, explosion-proof and climate
controlled control cabinet was
designed and manufactured in close
co-operation with Siemens AG.

A complex, dangerous process,
pigging can be made safer using
mechanical interlocks. However,
Netherlocks says a standard
interlocking system typically does not
include monitoring, is not linked to
the various pressure levels, and would
not include the facility for remote
operation of Motor Operated Valves.

The Netherlocks control cabinet
combines all these aspects into one
unit: remote MOV operation controls
are included, and correct pressure and
position of MOVs are conditional
requirements to release the keys for
each stage of the process.