API 687: A little RECAP and a Preview of What’s to Come Next in Chapter 0

I think it’s worth doing a little recap of the journey so far into API 687.In terms of our journey, measured in number of pages, we have only covered 2.5% of the API 687 document!

Isn’t that crazy?

Let’s review and remind ourselves how the document is structured:

(Page quantities to be used as reference, some pages in the document were left intentionally blank to create space or breaks between Chapters and Sections.)

The second edition of RP 687 has 9 chapters. The first is Chapter 0 (which serves as an introduction), followed by a chapter on what to do with Rotors, followed by six chapters that are machine specific, and finally a chapter on how to treat stationary components.

A page weight breakdown of all chapters can be seen in Table 1 below:

Most of our time will be spent on Chapter 0 (Intro), then General Rotors and Stationary components; and it seems that from all the equipment types, Axial Flow Compressors and Expanders have most of the content.

I must confess, I had not noticed this until I worked on this blog. I would have thought Steam Turbines or Centrifugal Compressors would have carried most of the weight due to how many are applied in industry.

Chapter 0 has the following structure:

Chapter 0 is comprised of 17 Sections and 11 Annexes.

Graphing how many pages per section or annex, we get the following distribution shown in Table 2.

So far in this blog, we have covered up to Section 3: Terms, Definitions, Acronyms, and Abbreviations.

The next section (Section 4) to be covered will provide a general overview of the Process for Inspection and Refurbishment. But the actual details on inspections methods and repair processes will be explained in Section 11 and Section 12.

What I am trying to convey is that, in this journey through this vast document, we will go through the topics several times: a general introduction at first, and then a deeper dive when we get to that topic’s dedicated section.

It is worth mentioning that the annexes are hidden gems within the document and should not be neglected for not being official sections.

Annex A: (informative) Selection of a Repair Shop Checklist

By far, Annex A will hold the most pages in the form of guidance, as well as a checklist on how to audit and select a repair shop or a repair partner.

I am a big nerd, and I will publicly admit that I love Checklists and I love Annex A. In my career as a manager, if the topic of “How should we set-up a turbomachinery shop?” ever comes up, I refer to API 687 Chapter 0, Annex A.

I have filled in many Annex A forms for equipment end users when they have qualified the shops I have worked at.

In terms of content, Annex A is no more than empty tables to be filled out, but it is like a great party game, surely to foster endless hours of fun technical conversations about capabilities and competencies in the world of turbomachinery repairs.

Annex C and D: (informative) Nondestructive Testing Method Guideline & Component Nondestructive Testing Methods

These two in my opinion go hand in hand. The first as a great introduction or CliffsNotes to the non-destructive methods used, and the second as a guide for which methods should be considered by component type. By components, API means what part or assembly, or feature is being assessed; for instance, how to inspect/test/assess a weld repair or a thermal spray on a shaft.

Annex G: (informative) Restoration Methods (Overview)

As the title suggests, this annex will be a very general overview of surface or material restoration methods.

This is also where the conversation within the task force started to get a bit tense or even controversial.

We are discussing restoration methods such as coatings, thermal sprays, and welding, and, as I mentioned last week in my post about ASME Boiler and Pressure Vessel Code Section IX, when people start applying heat to metals other people get very nervous, and rightly so.

After all we are working with rotating equipment, highly stressed components exposed to harsh environments.

This is where one must be open to have technically sound discussions with your repair partner, to fully understand the capabilities of the methods, the risks, and ways to mitigate them.

For instance, API 687 does not recommend utilizing laser welding methods. The writers considered laser welding an emerging technology with insufficient experience and procedures.

The first claim is not true anymore. Laser welding was born in the 60s and has now accrued 60 years of development and implementation. Laser cladding and other applications for turbomachinery repair had appeared in the industry by the 1990s. I know that my friends in a quaint little Dutch town called Venlo had pioneered the industrial application of lasers for repairing gas turbine parts before I had even graduated high school.

And lastly, consider that today most additive manufacturing (AM) methods use lasers. I will throw out a bunch of AM acronyms to make my point: SLM, LMD, DMLS, LENS. All are laser-based processes.

What worries most engineers, including myself, is that concerning the topic welding, we all respect the guidance provided by ASME’s Section IX on how to qualify welds. But so far there are no ASME Section IX chapters dedicated to laser welding.

There are some other resources, such as ISO 15614-11 or ISO 22826, which speak to qualifying welding processes, including laser beam welding or how to qualify operators of such machines, but nothing yet on exactly how to treat laser welding qualifications.

Until those chapters or sections show up, we can use the general principles established by ASME Section IX and our good engineering judgement and discipline to understand the capabilities and qualification of any process, including laser welding.

In the end, if we simply waited around for a standard to be written, we would deprive ourselves of innovating and inventing new things.

Annex H: (informative) Weld Repair Flowcharts

This is one of my favorites because it is a flowchart, and I love flowcharts. This Annex is so committed to the power of a flowchart that it does not have any introduction or additional text, just the flowchart!

Annex J: (informative) Outage Planning

I find it very interesting that in a document dedicated to equipment repairs, there is an Annex dedicated to “Outage Planning”. 17 whopping pages dedicated to all the steps and considerations during an outage, from Safety and planning through the entire lifecycle of an outage (pre-outage, execution and post-outage).

I am not complaining at all. I think this is another one of those hidden gems, and I would wish or recommend that all engineers in the industry look at this annex.

Maybe this annex has an impact on me, because most of my career I have spent looking at machines inside a repair facility and not in the field where they actually live and run. So, learning about pre-planning and what happens during and after an outage is very interesting to me.

To me, an outage is like planning a concert or huge event, like a Superbowl or Formula 1Grand Prix or choreographing a mechanical ballet!

Imagine the logistics required to move personnel, tools, and equipment. The considerations on how to even prepare to shut down a petrochemical process safely. How to manage thousands of contractors crawling through scaffolding and ensuring that it all happens safely and on time.

This to me is simply mind blowing. I have had an opportunity to participate in a few outage related planning parties, and I tip my hat to those engineers and admire those companies that dedicate up to several years preparing and planning for their outages.

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In truth all the Chapter 0 Annexes are worth peeking at. They all contain valuable insights related to the repair of equipment. I chose only to showcase the ones that seemed most fun to write about today. Do not despair; We shall go through all of them in the near future.

So, this is a preview of what is to come in the next following weeks as we continue our journey through API 687, specifically the rest of Chapter 0.