MPCU 
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 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

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