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“Mechanical Completion” – Commissioning Video Training Course – “The 9 Key Elements of Successful Plant Commissioning” – Part 3 of 10

Commissioning_Training - MindMap - The 9 Key Elements - MECHANICAL COMPLETION

What is Mechanical Completion?

Did you watch the 2nd commissioning video training lesson? Yes? Ok, then let’s continue with the 3rd lesson: Mechanical Completion

This commissioning training should remove the confusion about “What does it mean – MC – and whichs items are included and which not?”

I appreciate your comments and questions below the video very much!

You can watch the same video on YouTube as well.

Click here to watch the next video “P&ID CHECKING” (part 04 of 10).

And here is an overview about ALL commissioning training videos.

Download the mind map “MECHANICAL COMPLETION” in PDF format for FREE now

Commissioning_Training - MindMap - The 9 Key Elements - MECHANICAL COMPLETION

“The 9 Key Elements of Successful Plant Commissioning”
Click the mind map above to download your free PDF now!

Mechanical Completion – Video Transcript

Hello everybody,

Here is Thomas Stuenkel, founder of, a commissioning engineer and a commissioning manager.

Welcome to part three of my ten part commissioning video mini-training for commissioning newbies. I hope you already enjoyed part one and part two.

In the third part, I want to give you a detailed explanation of key element number two, mechanical completion. You will learn which items have to be carefully considered for a successful mechanical completion.

As always, I am using the mind map format for this presentation because it’s easier to remember. Of course, you can download this mind map on my download section on

Let’s start with a detailed explanation of key element number two, mechanical completion.

The nine key elements of successful plant commissioning. Element two, mechanical completion.

I want to give you, at first, a definition for mechanical completion.

Checking and testing of equipment and construction to confirm that the installation is in accordance with drawings and specifications, ready for pre-commissioning OR commissioning in a safe manner and in compliance with project requirements.

I put the OR in capitals and I marked it bold because mechanical completion can mean ready for pre-commissioning OR it can mean ready for commissioning. I will explain this a little bit more detailed later.

Typical tasks for mechanical completion are divided by disciplines: mechanical, piping, structural, electrical, instrumentation.

Typical tasks for mechanical are, for example: visual inspection for complete and correct installation, verification of nameplate details at tanks, vessels, rotating equipment and other machines. Internal inspection of tanks and vessels, hydrostatic test of vessels and tanks. It can take a long time, don’t underestimate hydrostatic tests. I have experience from one plant and there was a column. It was nearly hundred meters high and it took several weeks only to fill it up with water by trucks.

Vendor representatives for large and/or complicated equipment.

It’s a good idea to have the vendor representative onsite for complicated compressors, blowers, pumps, big pumps and so on. Dimension control is included in a typical task. Bolt tensioning. Preservation.

Typical tasks for piping are, for example, NDT is done. Non-destructive testing, pipe supports completed. All items subject to damage during flushing, cleaning and pressure testing are removed. Blowing, flushing, chemical cleaning, drying, preservation, re-statement, bolt tensioning. Insulation and flow coding is included as well but I put it here in brackets because, during this time, not all parts of the pipe will be completely insulated. Normally only the straight pipes will be insulated and the flange connections will be free for later checking.

For example, if pre-commissioning tasks start later for opening the flanges and to blow in or blow out. Flow coding will be done usually later as well.

The inspection of all supporting structure is the typical task for the structural discipline.

Electrical: We have to inspect cable trays, cable tray supports, the cable tray fill, the cables itself, the bend radius of the cables. The wiring, the termination, the grounding and for sure Megger testing.

Instrumentation: Inspections are similar to the electrical inspections. Cable trays, cable tray supports, cable tray fill, cables, bend radius, wiring, termination and grounding. Additionally we have to validate instruments. We have to validate the valves. Lube checks have to be done, flushing of tubing, tightness test of tubing.

Now the big question, what is included into mechanical completion?

The only right answer is, it’s defined in the contract. This can vary from client to client and from plant to plant. If you are not sure which activities are really included into mechanical completion, take the contract, read it, read it again, understand it and then you are really sure what is included.

I will give you two examples.

Example number one, here you can see our key element for successful plant commissioning. It starts with planning, it goes through construction completion, P&ID checking, pre-commissioning, mechanical completion, commissioning, start-up, initial operation, performance test and post-commissioning.

In this example, you can see mechanical completion. This means it’s ready for commissioning. In this task, the construction and commissioning team is involved. This means, in detail, construction is done, hydro testing is done, mechanical completion testing and pre-commissioning is done. Therefore we have here another milestone and this is called, usually, construction completion. This means ready for pre-commissioning, mainly the construction team is involved in this task. It means construction and hydro testing is done. You can see in this example, the pre-commissioning activities are included into the mechanical completion.

Mechanical completion means I’m ready with all my pre-commissioning activities like flowing, blowing, flushing, cleaning and all the things.

Let’s check example number two. It starts as well with planning then we have the mechanical completion milestone, P&ID checking, pre-commissioning, commissioning, start-up, initial operation, performance test, post-commissioning.

Here mechanical completion means it’s the same like construction completion and this is the same like ready for pre-commissioning. The construction and commissioning team is normally involved in this task. In detail it means construction done, hydro testing done, mechanical completion testing done.

The P&ID checking, usually it takes place as well at the same time. Mechanical completion, in this example, means ready for pre-commissioning. I will start with pre-commissioning activities after mechanical completion milestone is reached.

Again please remember mechanical completion is only defined per contract. You have to check, you have to read the contract and to understand it. This is the only right answer, the contract. It can vary from client to client and as well from plant to plant.

I summarize the third lesson:

We learned all items which have to be carefully considered for successful mechanical completion. We know that the definition of mechanical completion depends on the contract and every plant is different.

In lesson number four, I will speak in more detail about the third key element, P&ID checking.

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Thank you for watching, see you soon, Thomas Stuenkel.

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