What is the difference between QC Inspections and Commissioning Inspections?

Commissioning is complex, especially the transition from construction to commissioning. But with the proper documentation, this transition can be significantly simplified, and this is where the documents for QC Inspections and Commissioning Inspections are important.

There are three types of documents that are important to define during this transition.

• ITPs – which are the inspection and test plans
• Mechanical Completion checklists
• Pre-commissioning checklists.

Let’s review each of these documents.

What is the difference between QC Inspections and Commissioning Inspections?

Commissioning is complex, especially the transition from construction to commissioning. But with the proper documentation, this transition can be significantly simplified, and this is where the documents for QC Inspections and Commissioning Inspections are important.

There are three types of documents that are important to define during this transition.

• ITPs – which are the inspection and test plans
• Mechanical Completion checklists
• Pre-commissioning checklists.

Let’s review each of these documents.

Inspection and Test Plans

Inspection and test plans are part of the construction quality control documents. They’re referred to as ITPs or inspection and test plans, and they list the quality checks to be completed once systems are installed to confirm proper installation.

An example of a mechanical ITP is a checklist that lists all the torque values to be confirmed when equipment is installed. All bolts are torque checked to verify that they have been torqued correctly. Another example might be a checklist that confirms and verifies equipment is installed correctly such as flushing of the pipes to confirm there is no debris within them, leak or pressure testing to confirm that there’s no leaks on the piping, and these are part of the QC inspection documentation to confirm that piping is installed correctly.

An example of an electrical ITP is a checklist that lists all the checks to be done on cables after they’ve been pulled. This includes megger checking and point-to-point testing. Megger testing confirms that there is no damage to the cable and that its dielectric properties have remained intact after installation. Point-to-point testing verifies that the cable is terminated properly to the correct terminal blocks within the automation cubicle. All the ITPs are completed for a particular subsystem. Once all ITPs are complete, we can then document the mechanical completion.

Mechanical Completion

Mechanical completion is the formal handover process from the construction team to the commissioning team. Each mechanical completion lists all the ITPs that are related to a particular subsystem as well, mechanical completion checklist will list all the documentation that’s required as part of that particular handover. Once all items listed in the mechanical completion checklist have been completed, the checklist is reviewed and signed off signalling hand-over to the commissioning team who can commence with pre-commissioning testing. Learn more about Mechanical Completion, Substantial Completion, Final Completion

Commissioning Inspections

These inspection are defined in pre-commissioning checklists. An example of a mechanical pre-commissioning checklist is a motor and a pump that requires startup for the first time. In this checklist, a bump test is performed to confirm rotation, an uncoupled run is performed to confirm no infant mortality issues, a coupled run is performed to confirm current draw, and an initial run-in is performed to confirm pressure and flow rates. An example of an electrical pre-commissioning checklist is energizing an automation cubicle for the first time. In this checklist, it would contain basic communication checks, alarm and setpoint checks, control and monitoring checks, loop checks, and much more. Once all pre-commissioning inspections are complete the systems can then be further tested during commissioning testing.

Conclusion

To summarize, the main difference between QC Inspections and Commissioning Inspections is QC Inspections confirm that the equipment is installed correctly such as piping has been flushed, motor and pump have been torqued correctly, all components are aligned.  And commissioning inspections confirm that the equipment functions correctly such as it’s rotating in the correct direction, and it’s drawing the correct current with the proper pressure and flow rates.

You can also see a video explanation as well.  Be sure to check out our YouTube channel for more helpful videos on Commissioning and Startup.