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Paul began his career as an NDT technician, where he was Level 2 certified from ASNT (American Society for Non-Destructive Testing) in different fields including Ultrasonic Thickness Testing and Ultrasonic Flaw detection.

The following is a dialogue that Paul had with his students during the fourth Live Online Level One (LOLO) Ultrasound Certification Course.

Question: Should Compressed Air Leak Inspections be Performed During Planned Outages?

I am often asked about compressed air leak inspections… how often should compressed air leak inspections be carried out, should they occur during planned outages or regular operation hours, should the whole plant be inspected at once or should it be broken up into smaller more manageable sections.

Here are my recommendations for carrying out a successful compressed air leak inspection.

Safety

Safety is everyone’s number one job. Which is why I open every one of my LOLO Courses with the Poll Question, which profession suffers more casualties every year in the United States: Maintenance Workers or Firefighters? The answer is surprising to some. Even when performing a task as straightforward and “safe” as performing a compressed air leak survey, it is important to wear the correct PPE, earplugs, safety glasses, etc. And always remain aware of your surroundings.

Frequency of Inspection

According to the Department of Energy, compressed air systems that have been more than a year without inspection and maintenance are likely losing upwards of 35% of their compressed air to leaks.

So, when is the best time to perform compressed air leak surveys and inspections? During planned outages and shutdowns? No.

Ultrasound can be used effectively in extremely loud environments. The background roar of a production facility does not impede its ability to locate the hissing produced by compressed air leaks. Also, if assets are not in operation, automated valves that close when production is down would affect compressed air supply throughout the facility, rendering the results of an air leak survey inaccurate.

Knowing the network will improve the speed and efficiency of compressed air leak surveys, while also familiarizing the inspector with potential safety hazards.

The best way to get to know your compressed air network is to walk the inspection route prior. In a perfect world, you will be able to get your hands on schematics that illustrate piping locations, and the route of the compressed air flows.

Before beginning your ultrasonic inspection, you should have an idea of what type of challenges you will face, and which sensors you will want to use during your inspection.

Knowledge of the Network

Knowing the network will improve the speed and efficiency of compressed air leak surveys, while also familiarizing the inspector with potential safety hazards.

The best way to get to know your compressed air network is to walk the inspection route prior. In a perfect world, you will be able to get your hands on schematics that illustrate piping locations, and the route of the compressed air flows.

Before beginning your ultrasonic inspection, you should have an idea of what type of challenges you will face, and which sensors you will want to use during your inspection.

Update Plans

As with anything, your compressed air leak survey route is subject to change. Inspectors should always be looking for ways to make their routes safer, more efficient, and effective.

Plan the Inspection

You should be further breaking down your facility's compressed air system into smaller sections to tackle one at a time. This makes the task of performing a full compressed air leak audit more manageable. We recommend starting in the compressor room and working your way out.

We recommend defining the route using plans and diagrams with as much detail as necessary for other inspectors to follow.

You should also coordinate with the production supervisor so you can perform the inspection at an opportune time. The ideal time to perform the inspection is when there is low demand on the compressed air system, ensuring maximum pressure, therefore making leaks easier to locate.

Having knowledge of the most likely points compressed air leaks occur is also extremely beneficial.

Choosing your Equipment

Select an ultrasound tool and the attachments that best fit your needs for the inspection.

For example, you may want to use a parabolic dish if the piping you’re trying to inspect is far above your head on the ceiling, or you may want a flexible sensor if there are machines or other obstructions in the way of piping you’re trying to inspect.

Data management

When recording compressed air leaks in your database there are some things you want to make sure are recorded. For yourself, you should be recording the date and time the survey was performed, the locations of found leaks, leak tag numbers, and leak descriptions.

Using the free SDT’s LEAKReporter App , leaks can be quantified using decibels, and then their approximate cost is calculated. This can be helpful to show to management to justify performing regular compressed air leak inspections.

Celebrating Wins

Now I know it sounds hokey…but don’t forget to celebrate successes… brag a little. It can be as simple as putting up a graph showing realized savings from compressed air leaks repaired. Saving your company money and improving plant-wide sustainability should always be celebrated by the maintenance teams – and judging by the sorry state of some facilities' compressed air systems, the savings realized by a single compressed air leak survey can be in the tens, if not hundreds of thousands.