Part 2: 3-step procedure for surveying a wear location

A field survey is valuable only when the information collected is sufficient to clarify three issues: the actual operating conditions at the location, the factor governing the damage, and the solutions that the plant can consider.

Therefore, surveying a location does not stop at taking photographs or recording that “this area wears quickly.” The process needs to begin with the operating conditions, proceed through the diagnostic stage, and conclude with solutions that can be compared in terms of service life, cost, and risk.

1. The process for surveying a location consists of 3 steps

The three steps are carried out continuously from recording the current condition to developing solutions.

Step	Activities	Required outcome
1. Understand the operating conditions	Record wear, temperature, impact, corrosion, and relevant operating conditions	Obtain a set of information reflecting the actual condition of the location
2. Identify the priority factor	Evaluate which factor is governing and which factors only play supporting roles	Narrow down the cause that needs to be prioritized when developing the solution
3. Develop solutions based on service life and budget	Provide 2–3 solutions for the plant to compare	Provide options together with their technical basis, service life, cost, and risk

Step 1 focuses on collecting actual operating conditions. The method for recording the four groups of factors is presented in Part 1: 4 factors to measure when surveying material wear in an industrial plant.

Step 2 is the part most easily overlooked. A location wearing rapidly is not sufficient grounds to conclude that a material with higher hardness is required. Before making a selection, it is necessary to determine which factor has the primary influence and which factors only contribute to the damage process.

Step 3 converts the survey results into specific options. A solution needs to be considered simultaneously in terms of operating conditions, expected service life, and budget. If any one of these three factors is missing, the solutions do not yet have the same basis for comparison.

2. Preparation before entering the site

Some information can only be obtained while the equipment is operating, while some measurements need to be carried out during equipment downtime. Repair history, seasonal changes, or unplanned shutdowns depend on information from operators and operating logs.

Therefore, preparation needs to begin before the survey date.

2.1. Six items of information to confirm before the survey visit

Before entering the plant, it is necessary to clarify:

which equipment the damaged location is on and which section of the production line it belongs to
whether the equipment is expected to be operating or stopped on the survey date
the safety documentation that needs to be prepared and the completion deadline before entering the area
whether the person accompanying the survey team at the site directly understands the operating history of the location
the permitted scope of photography and any restricted areas
when the location was most recently repaired or replaced

The person accompanying the survey team at the site is particularly important. This person needs to understand the operating history of the location, not merely know the route to the equipment.

If the accompanying person does not know how the location has changed over time, the survey may still obtain photographs and measurements at one point in time but will lack the contextual information needed to explain what happened previously.

2.2. Review the operating log before going to the location

The operating log helps place field measurements in the correct context.

A location that was repaired one week ago and a location that has operated continuously for eight months cannot be evaluated in the same way based only on the surface appearance on the survey date.

The information that should be checked includes the time of the most recent intervention, repair frequency, and unplanned shutdowns. These data help the engineer determine what to focus on at the site and avoid interpreting a measurement separately from the operating history.

3. At the site, prioritize data that change over time

Once the equipment has been accessed, the work sequence should prioritize data that may change or cannot be reproduced in the same condition after the equipment stops.

Priority level	Activity to be performed
1	Measure temperature
2	Measure material moisture
3	Mark measurement points and take photographs
4	Measure the remaining thickness at the marked points
5	Measure drop height, angle of incidence, and cross-sectional area
6	Collect material samples for further examination where adequate equipment is available

The general principle is to measure first what changes over time, followed by measurements that can be repeated after the equipment has stopped or under equivalent conditions.

The method for obtaining each measurement and the corresponding instruments are presented in Part 1: 4 factors to measure when surveying material wear in an industrial plant.

3.1. Before leaving the location, recheck three items

Three items that are easily overlooked but directly affect the subsequent usability of the data are:

the measurement points have been physically marked on the equipment
photographs include a reference scale within the same frame
the intervention history and seasonal changes have been discussed with the operator

These items need to be checked immediately at the location. If anything is found to be missing after the equipment area has been left, the survey team may have to wait for another access opportunity before the missing information can be added.

4. Determine which factor is governing the damage

This is the core step of the diagnostic process and also the step that requires the greatest caution.

Determining the governing factor must be based on the actual data from each location. There is no fixed set of criteria that can be applied to every case when wear, temperature, impact, and corrosion occur simultaneously.

Before drawing a conclusion, three points need to be clarified:

Item to be determined	Purpose
Which factor is governing and which indications support that assessment	Identify the cause that needs to be prioritized
Whether two or more factors are acting simultaneously	Avoid evaluating each mechanism in isolation
In what way the current conclusion could be incorrect	Check the limitations of the assessment itself

The final item serves as a diagnostic verification step. If it has not yet been determined how the current assessment could be incorrect, the conclusion still needs to be stated cautiously.

A technical diagnosis needs to indicate the basis of the conclusion and the limitations of that conclusion, rather than simply presenting a cause that appears plausible.

4.1. When multiple factors act simultaneously

A location may deteriorate faster than expected when multiple mechanisms occur simultaneously.

For example, chemicals may soften the outer layer of the material, after which hard particles continue to remove the weakened layer and expose a new layer. When this process repeats, the deterioration rate may increase more rapidly than when each effect is considered separately.

One indication requiring attention is a location that fails more quickly than initially expected.

Combined damage mechanisms and methods for interpreting damage patterns are discussed in greater detail in the article Material wear mechanisms in industrial plants: 4 types of wear and how to identify them from the marks they leave.

5. Convert the survey results into 2–3 solutions for the plant to select from

Once the operating conditions and priority factor have been identified, the survey results need to be converted into solutions that can be compared side by side.

Each solution should clarify five groups of information:

Required content	Presentation requirement
Material group and fastening method	Material group under consideration, fastening method, and installation conditions at the location, including the allowable equipment downtime
Expected service life	Basis for comparison, reference cases, and corresponding operating conditions
Cost	Purchase cost and cost of use during each operating cycle, not only the material price per kilogram
Benefits and trade-offs	Expressed numerically where data are available and descriptively where quantification is not yet possible
Residual risk	Risks associated with the solution and the additional information required to reduce the level of uncertainty

Do not assume that only one solution should be provided.

GAC can analyze the operating conditions and develop technical options. The plant directly operates the production line, so the final decision needs to balance service life, budget, equipment downtime, and the acceptable level of risk.

6. Operators provide the portion of data that cannot be obtained from a single measurement

Field measurements reflect the condition at the time of the survey. Operators, however, understand how the location changes across multiple shifts, seasons, and repair cycles.

Four items should be discussed:

intervention frequency and the time of the most recent repair
seasonal changes in the material and when the most adverse conditions occur
instances when the production line had to undergo an unplanned shutdown because of this location
the effect of downtime on production output

Information from operations needs to be considered alongside field measurements. The two sources complement each other; they do not replace each other.

7. When the survey location cannot yet be accessed directly

Not every survey allows immediate access to the location that needs to be measured. The equipment may be operating, access to the area may be restricted, or the appropriate shutdown window may not yet have arrived.

In such cases, some information can still be collected, but the scope of the data needs to be recorded accurately.

Activity that can be performed	Recording method
Observe and take photographs from a safe distance	Clearly state that the location was not accessed directly
Measure temperature remotely with an infrared thermometer	Record the measurement distance and observation position
Consult the operator	Clearly identify the information as having been provided by the operator
Parameter that cannot yet be measured directly	Clearly record that it has not been measured and specify the conditions required to obtain the measurement during the next visit

Do not infer the remaining thickness from a photograph and record it as a direct measurement.

This recording method allows future users of the survey record to know exactly which parts were measured, which were only observed, and which still require additional data.

8. Field photographs must make it possible to relocate the exact position

Survey photographs are not used only for illustration. When taken correctly, they also help identify the location, extent, and orientation of damage patterns during subsequent inspections.

Item to be controlled	Implementation requirement
Reference scale	Place it within the same frame and on the surface being recorded
Camera angle	Take one photograph perpendicular to the surface and one oblique photograph to show the depth of the damage marks
Lighting	Use oblique lighting to make the damage marks clearly visible and minimize glare caused by direct lighting
File name	Link it to the project, location, monitoring point, and date of photography
Reusability	The scale markings must be readable and the orientation of the damage marks clearly identifiable

In addition to overview photographs, there needs to be a photograph showing the measurement-point mark within the same frame.

Without this photograph, a subsequent inspection may be able to identify the equipment but still be unable to determine the exact location previously measured.

9. The survey record must be sufficiently clear for future reuse

The survey record is not intended only for the personnel present during the survey. The information needs to be sufficiently clear so that another person reviewing it after a long period can still understand the location measured, the method used, and which data remain missing.

Information group	Information to be recorded
Location	Equipment and specific location on the equipment, not only the general equipment name
Four groups of factors	Data together with units and measurement basis
Damage patterns	Orientation, extent, and photographs
Measurement points	Location description and photographs showing identification marks
Measurements	Person taking the measurement, measurement date, and instrument used
Incomplete items	Information that could not be measured and the reason

The incomplete-items section is particularly important because it defines the scope within which the survey record can be used and identifies the information that needs to be added before a conclusion is drawn.

10. Responsibilities of the departments within the process

Activity	Person or department responsible
Prepare information before the survey visit	Survey engineer
Access and identify the actual location	Person with detailed knowledge of the equipment and its operation
Confirm operating conditions	Area supervisor or person directly responsible for the area
Identify the priority factor	Engineer responsible for material analysis
Select between the proposed solutions	The plant, based on operating conditions and actual requirements

The reliability of the results depends greatly on whether the operating conditions are correctly confirmed. If field input data are recorded incorrectly, the subsequent analysis may still lead to an unsuitable solution.

11. Limitations when applying the survey process

The three-step process helps organize field information into input for the analysis and solution-development stages. However, three limitations need to remain clear.

First, when a factor has not been measured, that status needs to be clearly recorded. Do not infer the missing value from the other three factors.

Second, this process does not replace an actual field survey. The content provides guidance on organizing data and the work sequence; it does not provide a conclusion for a location that has not been inspected.

Third, the four groups of wear, temperature, impact, and corrosion provide the minimum baseline. Some locations may require additional factors depending on the operating conditions.

Determining the governing factor when multiple mechanisms occur simultaneously still needs to be based on the actual data and damage patterns at each location rather than applying a fixed set of criteria to every case.

The three-step process is the method GAC uses to organize a field survey. The value of the process lies in connecting operating conditions, measurements, the history of the location, and the limitations of the data before proceeding to the solution-development stage.