MPCU Process Interlocking

The MPCU is a mechanically-programmed key exchange system and functions as a ‘mechanical PLC’. It is installed in the field to guide operators through complex, non-linear procedures. The MPCU guides the operator to open and close all valves in a safe order. This will eliminate any error, even when a step has to be repeated at different stages of the process.

Application of the MPCU

Mechanical interlocks enforce operation of multiple interrelated valves in a predefined order. Reverse operation can only be done in reverse order. A MPCU enables sequences that require repetitions of steps or reverse operations that are not performed in reverse order.

Mechanical Process Control Unit for valve interlocks

Mechanical interlocks enforce operation of multiple interrelated valves in a predefined order

A MPCU is required when:

  • reverse operation of valves is not in reverse order of initial operation
  • valve is used repeatedly within a sequence
  • valve is opened and directly closed before proceeding to the next sequence step

Some common examples relate to pigging:

  • involving H2S
  • ensuring multiple vent / drain / purge cycles are carried out and not by-passed before the closure door can be opened
Mechanical Process Control Unit for valve interlocks

A MPCU enables sequences that require repetitions of steps or reverse operations that are not performed in reverse order

MPCU’s are also used in the following processes:

  • reactor sequences
  • filtration skids to preventing vessel implosion
  • asorber / regenerator processes
  • semi-regenerator catalytic reforming units within gas sweetening

Download the Netherlocks MPCU product sheet