LOCATION
Mt Isa
VALUE
$400K
Scope of Work
APMS successfully completed the replacement of two leaking inlet nozzles at the IPL Mt. Isa Sulphuric Acid Plant Drying Tower and SO₂ Stripper during the planned Acid Plant shutdown.
The existing 2.2m diameter carbon steel nozzles, manufactured from AS3678 Grade 250 material, had experienced severe deterioration after years of service. Failure of the internal brick/refractory lining allowed sulphuric acid ingress, resulting in significant corrosion and damage to the parent steel material.
The APMS scope involved the complete replacement of both inlet nozzles with newly prefabricated assemblies. Due to the critical structural function of the nozzles, the works required detailed engineering planning including installation of temporary stiffening arrangements and carefully controlled step-by-step cutting and welding sequences to maintain tower structural integrity throughout the repair process.
These works were executed on the shutdown critical path, requiring close coordination with other shutdown activities to ensure schedule compliance. Dedicated day and night shift crews were mobilised to safely and efficiently complete the repairs within the shutdown window.
Project Resourcing
The project team included:
- Project Manager
- Welding / Tank Inspector
- Project Supervision
- Boilermaker, Coded Welder, Rigger, Confined Space Sentry & Rescue and Acid Specialist Personnel
Project Achievements
One of the major challenges faced by the APMS team was performing the nozzle replacement while acid continued dripping from trays located above the work area inside the tower. All internal activities were completed wearing fully encapsulated chemical suits with supplied breathing air to ensure personnel safety in the hazardous environment.
Repairs were meticulously executed in accordance with the prepared installation procedure. No activity was permitted to proceed without review and verification of the previous stage by both the APMS inspection team and the client representative, ensuring strict compliance with quality and safety requirements throughout the works.
Through excellent coordination between day and night shift crews, along with close collaboration with other service providers including crane operators, scaffolders and refractory installers, the team progressed the repairs efficiently and successfully removed the scope from the shutdown critical path.
All welding activities were completed to project specifications, with welds subjected to NDT inspection in accordance with applicable standards and quality requirements.
Most importantly, APMS completed the entire scope safely with zero injuries or incidents throughout the shutdown works.
Key Activities
The success of the project was dependant on the successful execution of the following activities:
- Preplanning of works including site visits and meetings, prior to site execution
- APMS experience working around hazardous chemicals and strong acid including the use of protective equipment
- Coordination of multiple service providers and materials suppliers ensuring everything is available on time and when required onsite
- Daily site reporting highlighting any potential issues/delays allowing mitigations set in place to reduce impact on schedule
- 100% pass rate for all NDT
