Many companies use Risk Based Inspection (RBI) to assess the risk of equipment as opposed to following an API 510 inspection approach. But what if you’re just starting your RBI program, or you are finally starting to buy into an RBI approach. What happens when your turnaround group is asking you what type of inspection needs to be completed on your feed/effluent exchanger. Per API 510 you’re relying on an inspector to correctly identify the applicable damage mechanisms, correctly identify an acceptable NDE method for each mechanism and finally identify where specifically to inspect for each mechanism. For a newer inspector this can be an overwhelming task.
Let’s take this example one step further. This inspector now goes into a turnaround planning meeting. Because he is using a condition based inspection program, he had to determine which damage mechanisms are applicable, he had to determine the correct type of NDE and he had to determine the suitable locations for inspection. All for an INTERNAL inspection. But in the meeting, planners tell him they aren’t opening the exchanger this turnaround. What is he left to do?
If he was stuck with only the API510 approach, he would have to fight for the planners to pull the bundle, or he would have to figure out a new plan. However if he were using a risk based approach, he would already have a plan with him for completing the inspection non-intrusively. This is because the inspection effectiveness tables he used to create his plan, already have the corresponding inspection equivalent between intrusive (opening and going inside the vessel) and non-intrusive (not opening the vessel) inspections. This is another of the major benefits to using a risk based approach; the RBI study has a built-in damage mechanism review and the Effectiveness Tables outline the type of NDE and coverage required per mechanism for both intrusive and non-intrusive methods. Thus, once the damage mechanism is identified, the inspector already has the inspection methods laid out for him.
If working with a risk based inspection program, as an inspector, you should try to almost always walk into your planning meeting with an intrusive and non-intrusive plan that you can hand over to your planning group. Each option should include at a minimum:
- Type of inspection (phased array, AUT, spot UT, etc.)
- Locations of inspection including:
- Exact Thickness Monitoring Locations (TMLs)
- Specific welds for inspection
- Total weld length to be inspected
- Company to complete the inspection (if contracted)
- Preparation Required
- Scaffolding
- Insulation Removal
- Surface Prep
- Approximate time and cost to complete the inspection.
This may seem like a lot of upfront work, but remember, a lot of the difficult part has been taken care of for you by the inspection effectiveness table. This extra work will allow you to give the planning team all of their options up front, this way the meeting is collaborative. Also, when your planning group has both options upfront, you allow them to make a more informed decision.
Remember, the turnaround group has the same end goal as you – complete a turnaround as quickly and efficiently as possible, while still completing all of the necessary inspections to maintain or improve the risk and reliability of the plant.
Are there other best practices that you or your company follow when putting together an inspection plan? Does your turnaround group already require multiple plans? I’d like to hear what you think is important or what your company uses as best practices.