The Difference between QC Inspections and Commissioning Inspections

 

Understanding Construction Quality Control

Construction quality control is a type of management system that aims to ensure that the deliverable fulfils the guidelines and standards laid by the client. These may include completion of the project within the scope of predefined work as well as avoiding disputes throughout the project’s life cycle. Quality is established by the client and regulatory agencies, and is usually based on regulatory and environmental guidelines. All the quality assurance procedures and requirements are recorded in the construction quality management plan.

There are two major facets of quality in construction: quality assurance (QA) and quality control (QC). While quality assurance describes the quality management-specific expectations and how to attain quality, quality control explains the plan to achieve the same. The construction quality control manager oversees this plan throughout different phases of the project.

Understanding Construction Commissioning

Building commissioning is a methodical process of balances and checks to ensure that building equipment and systems are constructed, designed, and operated for optimal performance. The commissioningmanagement company brings an all-encompassing approach to the process of design, and is accountable for thoroughly reviewing construction-specific documentation, testing and validating the specific equipment post-installation, and checking if building staff are trained properly to operate and maintain the installed equipment.

Apart from ensuring that building components, including cooling, heating, refrigeration and water systems, and air handling work as they are expected to be, commissioning companies in the UK also aim to lower maintenance and operational costs as well as improve the building’s energy usage.

Although installation contractors and design professionals are eventually accountable for testing building systems and ensuring the quality of the installation, the commissioning team provides a second pair of ears and eyes throughout the entire construction process – checking for any deficiencies as well as preventing and resolving possible issues before the building becomes fully operational.

 

QC Inspections vs. Commissioning Inspections

Commissioning is a complex process, particularly the phase of transition to commissioning from construction. However, with the proper documentation, it can be simplified substantially. This is where the documents for QC and Commissioning Inspections comes in.

There are basically 3 types of documents that have to be defined during the transition.

      ·  Inspection Test Plans (ITPs)

      ·  Mechanical Completion Checklists

      ·  Pre-commissioning Checklists.

Let’s look at these three types of documents in detail.

 

Inspection and Test Plans

Primarily, these are part of the construction-specific quality control documents. Inspection and test plans, acronymed as ITPs, list the quality inspections to be done in order to confirm appropriate installation, once the systems are installed.

For instance, a mechanical ITP is a checklist that includes the torque values that need to be confirmed after equipment installation. Every bolt is torque-checked to see if they are torqued appropriately. Another ITP example can be a checklist to verify and confirm if equipment is installed correctly, including flushing of pipes to confirm they contain no debris, pressure or leak testing to verify that the piping has no leaks – and as part of the QC inspection documentation, it confirms that piping has been installed correctly.

An example of electrical ITPs can be a checklist, comprising all the inspections that need be done on all cables after being pulled. This may include point-to-point testing and Megger checking. Megger testing confirms that there is no damage to the cables, with its dielectric properties being maintained well post installation. Point-to-point testing confirms that the cable has been terminated appropriately to the right terminal blocks in the automation cubicle. All ITPs are specific to individual subsystems. Once all ITPs are done, the mechanical completion documentation begins.

 

Mechanical Completion

Mechanical completion is the process of formal handover to the commissioning team from the construction team. Every mechanical completion contains all the ITPs associated with a specific subsystem, and the mechanical completion checklist will include the documentation, which is needed as part of that specific handover. Once all the items listed in the mechanical completion checklist is completed, the checklist is verified and signed off, indicating handover to the commissioning team, which can then start with the pre-commissioning testing.

 

Commissioning Inspections

Commissioning inspections are specified in pre-commissioning checklists. An example of a pre-commissioning mechanical checklist can be a pump and a motor that need startup for the very first time. In such a checklist, a bump test will be performed to verify rotation, an uncoupled run will be done to see there are no issues, a coupled run will be done to verify current draw, and an initial run-in will be done to check flow and pressure rates.

An example of a pre-commissioning electrical checklist can be powering up an automation cubicle for the very first time. Such a checklist will include primary communication checks, set-point and alarm checks, monitoring and control checks, loop checks, and so forth. Once all pre-commissioning inspections are done, the systems can further be tested during the commissioning testing phase.

To make their entire commissioning inspection process faster, smoother and more efficient, most commissioning management companies rely on advanced commissioning management software like Cobia that helps ensure clear tracking, traceability and accountability for every stage of the commissioning process.

Conclusion

With the discussion above, the major difference between QC inspections and commissioning inspections is quite clear. Hence, it can be concluded that while QC inspections confirm that the equipment has been installed appropriately, commissioning inspections verifies that the equipment is functioning correctly.