Boiler and steam plant PLC migration
For Steamtech Engineering, legacy boiler PLC programs were migrated to current platforms and verified through structured I/O testing for repeat OEM deployment.
Industry · 08
Process Plant Automation for Chemicals, Process and Utilities
Metromotion Controls designs, programs and supports process control systems for chemical, process and utility plants across Melbourne, Victoria and Australia, working from the P&ID to PLC, SCADA, historian and switchboard design.
Process plants are controlled differently from packaging lines. The work is dominated by regulatory loops, interlocks, sequences that move material between vessels, and utilities that every other area depends on. Metromotion Controls reads the P&ID the way the process behaves, then designs the PLC and SCADA architecture, the loop strategy and the alarm philosophy around it, with PLC programming, historian data and switchboard and MCC design delivered by one team.
Most Australian process sites run a mix of PLCs, SCADA and sometimes a legacy DCS. We work across Rockwell, Siemens, Ignition, AVEVA and Citect, and our guide to DCS vs SCADA vs PLC for Australian process plants sets out how to choose the right architecture before a migration or expansion.
Sector Challenges
Problems we solve
01
Loops that are tuned once and left alone
Temperature, pressure, level, flow and ratio loops drift as equipment, product and throughput change. Poorly tuned loops show up as oscillation, off-spec product, wasted energy and operators running in manual.
02
Legacy PLCs, SCADA and DCS nodes
Older controllers and control-room software become hard to support, spares grow scarce and knowledge sits with a few people. Replacing them has to happen around campaigns, shutdowns and a plant that cannot stop for long.
03
Utilities that the whole site depends on
Boilers, steam, hot water, chilled water, compressed air and effluent systems are rarely the focus of investment, yet a trip in any of them stops production across the plant.
04
Alarm floods and thin operator context
Process upsets generate cascades of alarms. Without rationalised priorities, trends and clear sequence status, operators cannot see what started the upset or what the plant needs from them.
Our Approach
How we deliver
We start with the P&ID and a walk of the plant, then write the control philosophy: how each unit starts, runs, holds and shuts down, which loops are regulatory and which are sequential, and what the interlocks protect. Loops are designed to their dynamics, with PI control on fast flow and pressure loops, full PID with anti-windup on slow thermal loops, ratio and flow-paced control for blending and chemical dosing, and averaging level control where a tank should absorb variation rather than pass it downstream.
Sequences and batch operations are structured to ISA-88 where the process calls for it, so recipes, phases and equipment modules are reusable and testable. PLC programming covers continuous control, sequencing, permissives and trip logic, with safety instrumented functions kept distinct and engineered through our functional safety service where the risk assessment requires them.
SCADA and historian design gives operators rationalised alarms, process trends and sequence status, and gives engineers the data to tune loops and track energy and utility use. We work in Ignition, AVEVA, Citect and FactoryTalk, and design the historian so process data can support reporting without rework.
Power and field infrastructure is designed with the control system rather than after it. That covers control panels, switchboard and MCC design to AS/NZS 61439 with fabrication by partner builders, drive selection for pumps and fans, and OT networks with secure remote access for support.
Upgrades are staged around campaigns and shutdowns, with source-code review, simulation, FAT, cutover run sheets and rollback points, so a legacy PLC, SCADA or DCS node can be replaced without turning the outage into an open-ended fault-finding exercise.
Typical Work
Projects in this sector
Hot water and thermal process control
For Patties Foods, closed-loop hot water temperature control and PLC-managed cycle timing held set point and dwell consistently run to run.
Distributed control of a critical CIP system
For McCormick, a production-critical CIP system was migrated to Ignition SCADA with distributed control architecture and multi-terminal operator access.
Greenfield process plant with regulated loops
For La Casa del Formaggio, the process control scope covered 30 PID loops, 3 Motor Control Centres, 21 PowerFlex525 VSDs and an Ignition application.
Platforms
Technology we work with
Process plants need control platforms that support stable regulatory control, long asset life and clear diagnostics for the site team.
01
Rockwell ControlLogix and CompactLogix, Siemens S7 and TIA Portal for process control and sequencing.
02
Ignition, AVEVA, Citect and FactoryTalk SCADA with historian and reporting.
03
Instrumentation, analysers, drives and valve integration over EtherNet/IP, Profinet, Modbus and OPC UA.
04
Switchboards, MCCs and control panels designed to AS/NZS 61439 and fabricated by partner builders.
ISA-88 batch control and ISA-5.1 instrumentation conventions on P&IDs.
IEC 61511 safety instrumented systems where the risk assessment requires them.
AS/NZS 61439 assemblies and AS/NZS 3000 wiring rules.
IEC 62443 zones and conduits for OT network segmentation.
Common Questions
Frequently asked
Do you work on chemical, process and utility plants as well as food and beverage?
Yes. The control problems are shared: regulatory loops, interlocks, sequencing, batch control and utilities. Metromotion Controls applies the same process control discipline to chemical blending and dosing, boilers, steam, hot water and plant utilities that it applies on dairy and beverage sites.
Should a process plant use a DCS, SCADA or PLCs?
It depends on the size of the plant, how tightly units interact, the support model and the installed base. Many mid-size Australian plants run PLCs with SCADA and a historian, while large integrated plants often justify a DCS. Our DCS vs SCADA vs PLC guide sets out the trade-offs.
Can you replace a legacy PLC, SCADA or DCS node without a long shutdown?
Usually. We review the existing code and I/O, simulate the new system, run FAT and plan the cutover with rollback points, so the replacement fits a planned shutdown or is staged unit by unit.
Do you design switchboards and MCCs for process plants?
We design them. Metromotion Controls prepares switchboard and MCC designs to AS/NZS 61439, and partner switchboard builders fabricate them. We review shop drawings, witness FAT and support installation.
Do you tune existing process loops?
Yes. We review loop behaviour from trends, check the instrument and final control element first, then retune to the loop dynamics and document the settings so the site can maintain them.
Related Expertise
More process plants automation resources
Service
Industrial automation project delivery
Melbourne automation contractor capability for scoped control-system projects from design through commissioning.
Service
PLC and SCADA programming Melbourne
PLC logic, SCADA architecture, HMI upgrades, fault finding and historian integration for production sites.
Service
Switchboard and MCC design
Industrial switchboard and MCC design to AS/NZS 61439, with fabrication by partner switchboard builders.
Service
Functional safety and SIL
Functional safety assessment, SIL determination, safety instrumented functions and machine safety to IEC 61508, IEC 61511 and ISO 13849.
Service
Plant Intelligence: factory data and OEE
OEE, reports, quality, CIP, maintenance and energy data from the team that builds and programs the lines.
Service
Automation upgrades and retrofits
Modernise legacy PLC, SCADA, HMI and control infrastructure with staged cutover planning.
Project
Steamtech legacy boiler PLC migration
Legacy boiler PLC programs migrated to CompactLogix for an OEM, verified through I/O testing and commissioned at end-customer sites.
Project
Patties Foods hot water set automation
Fit-for-purpose temperature and cycle control for a hot water set forming and cooking process.
Project
McCormick CIP automation on Ignition
CIP automation and Ignition platform work for factory automation upgrades.
Insight
DCS vs SCADA vs PLC for process plants
How to choose a control architecture for an Australian process plant, expansion or migration.
Insight
From a P&ID to control logic
How an experienced team reads a P&ID and a short conversation and turns it into sequences, interlocks and control loops.
Insight
PID loop tuning for food and dairy processes
Why most flow, pressure and level loops run PI, why slow thermal loops justify full PID with anti-windup, and a structured lambda method over trial and error.
Insight
Batch control and ISA-88 for food manufacturers
A practical guide to ISA-88 batch control covering the procedural model, equipment mapping and traceability.
Insight
VSD upgrade guide for pumps and fans
When a variable speed drive saves energy, how to build the case and how to replace an ageing drive.
Insight
AS/NZS 61439 for switchboards and control panels
A designer's guide to responsibilities, ratings, design and routine verification and FAT evidence under AS/NZS 61439.
Ready to discuss your process plants project?
Tell us the site change, upgrade or support requirement. We'll review the scope, timing and technical constraints and respond with a clear next step.