Measurement and control have continued to evolve since the first industrial revolution, following the demands of industrialization and sometimes anticipating them.
Early in the history of industrialization, instrumentation and automation were adopted to standardize production processes and reduce the physical efforts of workers. In recent years, instrumentation is widely used to control environmental pollution, save energy, increase plant safety and capacity.

Old cable trays Old cable trays

Casale has proven experience as an international world-class Process Licensor and EPC Contractor, for the realization of new LSTK projects and for the revamping of existing plants.
Casale instrument engineers have right experience, competences and background, not only to cope with the execution of the mentioned projects but in general to cope with any kind of technical challenge related to instruments and process controls.

Case History

Revamping of two ammonia plants for an important European Customer, from feasibility to EPC contract.


The two plants were erected in the early seventies of the last century and were similar in capacity and performance.


Scope of the revamping was a combination of capacity increase, energy saving and reduction of emissions. At the mean time the Client requested Casale to modernize the control system introducing a Distributed Control System (DCS) and an Emergency Shutdown System (ESD).
The existing instruments were of the pneumatic type as per the original installation.
Plant control was based on local PID controllers having also problems of maintenance due to shortage of spare parts.


  • Revamping activities had to be performed in different steps and in different years for the two plants in order to minimize the shutdown periods;
  • The documentation was not up to date with the current state of operation due to some changes made over the years;
  • The true state of equipment, logics, and measurements was known only to few engineers, operators and technicians;
  • Most of the instrumentation was obsolete and the original manufacturers were no longer in business.


The first step of the project was to conduct a detailed site survey for each plant.

This activity had two main targets:

  • Compare the available documents with the actual as-built installation and get a set of reliable documents;
  • Verify the hardware in order to identify in detail the instruments to be changed and the ones that could be maintained.

Both the targets had been met:

  • All the information and data gathered during the survey had been transferred to a complete set of red-marked documents;
  • It was discovered that many flow elements, control valves, on-off valves, and some safety valves needed to be replaced, while most of the field instruments needed to be changed because they were of the pneumatic type.

After this crucial step Casale could start the engineering activities relying upon updated documents and reliable data.

For the automation it was decided to realize a new centralized control room for the two ammonia plants and the existing urea plant also subject to revamping by another company.

Control Room before revamping
Control Room after revamping
Control Room: before and after revamping

Casale designed the architecture of the common system (DCS and SIL certified ESD) of the three plants, integrating in the new system the new logics with the existing ones.

The existing local auxiliary rooms had been reused for the installation of the new DCS and ESD cabinets.

Regarding the instruments and the field part, all the valves considered suitable after the survey had been also verified for suitability with the new process conditions. The not suitable ones had been substituted with new ones.

Reactor valves before revamping
Reactor valves after revamping
Reactor valves: before and after revamping

Moreover, a detailed study was performed to select the best possible new cable trays paths across the plant.
Civil section was also involved in order to reinforce the existing pipe racks where necessary.

New cable trays New cable trays


Both plants had been successfully revamped meeting performance guarantees and schedule.