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Let’s Talk About Inspection Planning 

KTA’s Certified Coating Inspector Forum Volume 3, Issue No. 1 – January 2024

William Corbett, COO

AMPP Senior Certified Coating Inspector & Certified Protective Coating Specialist

KTA’s Certified Coating Inspector Forum is designed to provide professional development/continuing education on standards, inspection practices, new instruments, and other topics to help keep certified AMPP and FROSIO coating inspectors current. It represents the views of the author and KTA-Tator, Inc. It may or may not represent the views of AMPP: The Association for Materials Protection & Performance, even though SSPC, NACE, and AMPP standards are frequently referenced in the content.

Introduction

The January 2023 edition of the KTA Certified Coating Inspector Forum focused on how an inspector can effectively use coating manufacturer product data sheets (PDS) when preparing for a project. The article went on to say that developing an Inspection Test Plan (ITP) is a good way to capture all the inspection checkpoints and corresponding acceptance criteria from a project specification, and to determine whether any of the criteria conflict with the PDS, and vice-versa. In this issue of the KTA Certified Coating Inspector Forum, we’ll describe a process that can be used to create an ITP.

When asked, “What do you do for a living?” you may respond, “I inspect coatings.” But there is actually a structured approach to what you do, and I’d argue “Inspect” is Step 3 of the process. That is, you should Plan, Prepare, then Inspect. The planning and preparing steps are essential to the process yet are sometimes overlooked. This column focuses on these first two steps of a quality inspection process, and how planning and preparing can help you become an even better coating inspector.

Planning for Inspection of Surface Preparation and Coating Installation

The first step of the planning process involves gathering project documents. This includes:

  • The Project Specification
  • Manufacturer’s PDS and Safety Data Sheets (SDS) for the materials to be used, such as the Abrasive (if abrasive blast cleaning is required) and each Coating Material
    • Note: The project specification may refer to the abrasive and/or coating system generically (e.g., expendable abrasive; an organic zinc primer, polyamide epoxy mid-coat, polyaspartic finish coat) and provide a Qualified/Approved Product List (QPL/APL) that the contractor can select from. In this case it is important to determine from the owner or contractor the actual products to be used so that the correct PDS and SDS can be obtained in advance.
  • Referenced Standards listed in the Project Specification (e.g., ASTM, SSPC, NACE, etc.)
    • Note: When gathering referenced standards, make sure to obtain the correct version. Some project specifications will reference a specific publication date (e.g., SSPC-PA 2-2018), while others may state that the latest published version is invoked (which in the case of SSPC-PA 2 is the 2022 version). Also note that ASTM and SSPC/NACE standards are copyrighted documents and need to be purchased prior to downloading. Once all documents are in hand the process of establishing an Inspection Test Plan can begin.

What is an Inspection Test Plan?

The second step in the process is to develop an Inspection Test Plan or ITP, which is essentially a “road map” for both Quality Assurance (QA) and Quality Control (QC) inspection personnel. An ITP lists what to inspect (i.e., the inspection checkpoint), how to inspect (i.e., the method of inspection), and the acceptance criteria (i.e., what is acceptable according to the project specification). By developing a well-organized ITP, the potential to overlook specific inspection check points/hold points invoked by the project specification is minimized, and it effectively enables QA and QC inspectors to focus on the inspection requirements in what may be a lengthy, complex contract.

An effective ITP covers all phases of work in the sequence in which they will occur. Preparing a plan essentially requires an inspector to navigate through and extract inspection check points from the specification, review the requirements of the PDS for the coating being used, and transfer them to a more focused document. Sometimes called a Quality Control Plan, an ITP is frequently a contractor submittal that must be reviewed and accepted by the owner prior to initiating work. It provides a key communication tool between the facility owner and QA and QC inspection personnel once the project begins.

The ITP must include all inspections required by the specification, but not add to them.  For example, while holiday detection is an important inspection step for tank linings, if it is not required by the specification, it cannot be included in the ITP. In this example, advise your supervisor of the discrepancy so that the Owner or specifier can determine if the specification should be revised. Likewise, if your review of the PDS in conjunction with the specification shows potential conflicts, they should be disclosed. While the specification takes precedence over the PDS, discrepancies should not be ignored. For example, if the specification requires a primer thickness of 2 to 6 mils, but the PDS restricts the thickness to 2 to 4 mils, this discrepancy cannot be overlooked.

QA inspectors may prepare their own ITP since the scope and extent of their inspections may differ from those of the QC inspector. When this is done, it is important to verify that the plans do not conflict with each other. Also, ITPs do not replace the project specification or manufacturer’s PDS but supplement them. An ITP is simply an aid to an inspector.

Creating an Inspection Test Plan

After nearly two decades of instructing the SSPC Protective Coating Inspector and Bridge Coating Inspector training programs (both of which required development of an ITP as a component of the Level 2 examination/certification process), I’ve come to realize that creating an ITP from scratch is not intuitive. So I’ve attempted to simplify the process by creating an ITP columnar format. While there is no standard format (and the project specification may require a specific format), I’ll describe two approaches – a simple 3-column format and a more complex 6-column format (3 columns from the simple format and 3 additional columns). When extracting the inspection checkpoints from the project specification, I like to begin each with the verb “verify,” which infers an action to be taken.

Simple ITP Format

Create a 3-column table using Microsoft Excel or Word as shown below.

Inspection CheckpointTechnique/InstrumentAcceptance Criteria
   

Extract the inspection checkpoints and the acceptance criteria directly from the project specification and PDS as applicable, and list them in columns 1 and 3, respectively. Ideally the checkpoints are listed in the order in which they will occur. If the project will be done in stages, the inspection checkpoints will be repeated each time a portion of the structure is prepared and coated.

Once columns 1 and 3 are populated, complete column 2, recognizing that the project specification may have specific requirements regarding the inspection technique or instrument. For example, there are 4 methods for measuring surface profile described in ASTM D4417: Methods A (visual comparator), B (depth micrometer), C (replica tape), and D (stylus surface roughness instrument), but the specification may invoke a specific method (e.g., Method C).

Simple ITP Sample (portion only; not a complete plan)

Inspection CheckpointTechnique/InstrumentAcceptance Criteria
Verify correct coating materials (receipt inspection)VisualXYZ Coatings Co: Organic Zinc Primer OZ1595 / Epoxy Mid-coat E4409 / Polyurethane Finish PU1754
Verify compressed air cleanlinessBlotter TestNo visible oil/water on collector
Verify abrasive cleanlinessOil and Conductivity TestsNo visible oil; conductivity below 1,000 µS/cm
Verify surface profile depthReplica Tape/Micrometer2-3.5 mils
Verify surface cleanlinessSSPC-VIS 1SSPC-SP 10
Verify surface soluble salt remediationChlor-Test Kit< 7 µg/cm2 chloride
Verify proper mixing/thinningVisualPer Manufacturer PDS (complete kits only)
Verify primer thicknessType 2 Electronic Coating Thickness Gauge3-5 mils

Complex ITP Format

Alternatively, if you want a more complete tool, create a 6-column table using Microsoft Excel or Word as shown below. Note that columns 1, 2 and 6 (blue fill) are the same 3 columns as the Simple Format. Columns 3, 4 and 5 (yellow fill) are new and provide greater detail. The frequency is extracted from the Standard Test Method referenced unless the specification provides a different frequency. The Standard Test Method is extracted from the Referenced Standards section of the specification, and the Specification Reference is where the inspection checkpoint is located within the specification for quick access in case there is a question.

Inspection CheckpointTechnique/ InstrumentFrequency of TestsStandard Test MethodSpecification ReferenceAcceptance Criteria
      

Complex ITP Sample (portion only; not a complete plan)

Inspection CheckpointTechnique/ InstrumentFrequency of TestsStandard Test MethodSpecification ReferenceAcceptance Criteria
Verify correct coating materials (receipt inspection)VisualPrior to surface preparationNASection 3; Item 3.7.1XYZ Coatings Co: Organic Zinc Primer OZ1595 / Epoxy Mid-coat E4409 / Polyurethane Finish PU1754
Verify compressed air cleanlinessBlotter TestStart of shift; every 4 hours thereafterASTM D4285Section 3; Item 3.4.1No visible oil/water on collector
Verify abrasive cleanlinessOil and Conductivity TestsPrior to first use; prior to each reuseSSPC AB2/AB3; ASTM D7393; ASTM D4940Section 3; Item 3.5.2No visible oil; conductivity below 1,000 µS/cm
Verify surface profile depthReplica Tape/ Micrometer2 readings per location; Minimum 3 locations/shiftASTM D4417, Method C; SSPC-PA 17Section 3; Item 3.6.42-3.5 mils
Verify surface cleanlinessSSPC-VIS 1All prepared surfacesSSPC-SP 10Section 3; Item 3.6.6SSPC-SP 10; coat within 8 hours
Verify surface soluble salt remediationChlor-Test Kit5 tests for each 1000 sfSSPC Guide 15Section 3; Item 3.6.7< 7 µg/cm2 chloride
Verify proper mixing/thinningVisualPrior to each mixNASection 3; Item 3.7.2Per Manufacturer PDS (complete kits only)
Verify primer thicknessType 2 Electronic Coating Thickness Gauge5 spot measurements per area; No. of areas dependent on square footage coatedASTM D7091; SSPC-PA 2Section 3; Item 3.8.23-5 mils

Preparing for Inspection

Armed with project documentation and a freshly prepared ITP you are now ready to begin inspecting, correct? Not so fast. The next step in the process is preparing for inspection. Preparation includes:

  • Acquiring pre-project safety training (e.g., lead exposure, confined space entry, fall prevention, etc.) and/or required medical surveillance such as pulmonary function/respirator fit, blood and urine tests, annual physical, visual acuity, etc.
  • Obtaining Personal Protective Equipment (PPE) that is compatible with jobsite conditions and rules, such as hardhat, traffic vest, respirator, harness & lanyard, hearing and eyesight protection, footwear, etc.
  • Verifying the type of inspection equipment required for the project, as well as battery status (and spare batteries), accuracy verification, and currency of calibration. Note that instrument calibration may take several weeks so sending your inspection instruments for annual calibration should be done well before the project is scheduled to begin.
  • Verifying your Inspector Certification credentials are current and will not expire mid-project.

Now that you have both planned and prepared, you are ready to inspect. Equipped with all the project documentation and your inspection plan you are ready to provide the level of inspection that you have been trained and certified to perform.

Summary

A properly prepared Inspection Test Plan can provide a roadmap of what to inspect, how to inspect, and what the acceptance criteria are, while minimizing the risk of missing an inspection checkpoint, or invoking an incorrect requirement.

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