Key to safe pipe pigging
November 1st 2009 Dutch industrial and valve safety
expert, Netherlocks B.V. has been
chosen to supply its trapped key
interlocking safety systems by Indian
engineering and construction
conglomerate, Larsen & Toubro.
The company has ordered
Netherlocks products to secure and
safeguard 'pigging' pipeline cleaning
operations for two major projects.
The process is potentially high risk
due to high pressures and dangerous
gasses involved.
The trapped key interlocking
systems ensure that
each stage of the
process can only be
started – that each
valve can only be
operated – once the
stage before has been
safely completed. In
this way, the system
mechanically enforces a
strict and absolute
adherence to safe
procedure.
Because pigging procedures are
often non-linear processes, requiring
steps that may need to be repeated at
different stages, or that are dependent
on several previous actions,
Netherlocks designed the MPCU. The
MPCU acts as a 'mechanical PLC',
checking each stage of the process
and releasing keys according to preprogrammed
parameters, so the
operation can only be performed
according to safe procedure. More articles from Netherlocks BV: | 
