9.3 PT Procedures, ASTM/ASME Standards, and Acceptance

The ASNT NDT Level II liquid penetrant general exam lists Inspection Procedures and Standards as official PT topic 4. The specific exam (General Industry or Pressure Equipment) spends its codes, applications, and techniques items in the same neighborhood: can you read a procedure paragraph and do what it says? This section is where those two papers meet.

A procedure is the controlling work instruction for a given part family. It is not a textbook chapter and it is not "the way we have always washed Method A." ASTM E1417, AMS 2644, ASME Section V, Article 6, and a construction code can all be invoked by that procedure. They are not interchangeable, and none of them is an ASNT-published accept/reject table for every job.

Essential variables the Level II must actually run

An essential variable is a process setting that, if changed beyond the procedure's allowed range, can change detectability. Industry PT procedures — and the technique articles they invoke — treat at least the following as essential. Learn the list; the specific exam prints a subset and asks what you may not freelance.

Related settings the procedure may also treat as essential: penetrant sensitivity class (Type I), pre-clean method, drying temperature and time, emulsifier type, water-wash nozzle distance, and the evaluation window after developer application. If the document lists it as essential, the Level II does not "improve" it on the floor.

Industry practice numbers you will see attributed to ASTM E1417 and ASME Section V, Article 6 — not as ASNT secrets — include a common part-temperature band on the order of 40–125 °F (5–52 °C) for standard penetrants, Type I UV-A at the surface often ≥ 1000 μW/cm² with ambient visible light held down (frequently ≤ 20 lux / 2 fc), and Type II white light often ≥ 1000 lux (100 fc). Special penetrants and qualified high- or low-temperature procedures exist; they are used only when the approved document says so. If a stem prints 50–100 °F and a 10-minute dwell, those printed numbers win for that item.

Changing type, method, dwell, removal, developer, lighting, or temperature outside the allowed range is not a field tweak. It is a different examination. That change belongs to the Level III or the owner who approves procedure revisions.

Which document does which job

Mixing these four families is the most expensive topic-4 mistake on both papers.

How they stack on a real job:

1. The owner or Level III writes a procedure that invokes a practice (E1417 and/or ASME V Article 6), names AMS 2644-qualified (or otherwise approved) materials when the contract requires that list, and points to an acceptance standard (ASME VIII, AWS D1.1, etc.).
2. The Level II runs the essential variables and evaluates indications against that acceptance standard.
3. If the contract is AWS structural welding, AWS D1.1 workmanship limits apply when the procedure says they do — not the vessel table from last week's job.
4. If the contract is an ASME pressure vessel, Section V Article 6 is the usual technique reference and Section VIII (or the applicable book) supplies acceptance. Article 6 does not "include" the VIII table just because both say ASME.

Other documents appear in stems. ASTM E165 is a companion PT test-method / practice family; treat it as another how-to, not as ASME VIII. Employer written practices written to SNT-TC-1A or CP-189 govern personnel qualification; they do not replace E1417 or the construction code. ASNT Certification Services LLC does not publish a universal PT accept/reject table that outranks the code on the drawing.

Level II applies; Level III or the owner writes

Keep the responsibility line as clean as it was in the Level I / II / III chapter.

The Level II:

• Selects the approved procedure that matches the part, specification, and method
• Verifies essential variables (type, method, dwell, removal, developer, lighting, temperature) before production interpretation
• Classifies indications, measures them by the procedure's method, and applies the named acceptance standard
• Reports results, including required sketches or photographs
• Stops the examination when the procedure cannot be followed or when no acceptance criterion is provided

The Level III (or the owner / Responsible Level III named in the written practice):

• Writes or approves the procedure and the acceptance standard to be used
• Approves changes to essential variables
• Resolves interpretation disputes and "the code is silent" cases
• Specifies process-control pieces, material qualifications (AMS 2644 or equivalent), and any demonstration on a qualification block

The Level II does not rewrite dwell because the line is backed up. The Level II does not swap Type II visible for Type I fluorescent to "see better" without an approved alternative. The Level II does not borrow ASME VIII limits on an AWS D1.1 fillet because the VIII table is the one they memorized. The Level III does not stand at the booth and classify every stain on a production shift — that is the Level II's job under the document the Level III already approved.

On the ASNT central credential, the written exams test this model. Your employer's practical still belongs to the employer's written practice. Those are parallel facts, not a reason to ignore the printed procedure on the specific exam.

Reporting: location, size, type, sketch or photo

If it is not recorded, it was not a controlled examination. ASME Section V, Article 6 and ASTM E1417 both expect a record that lets another qualified person reconstruct what was done. A report that says only "PT OK" fails topic 4 even when the part is clean.

Typical report content the procedure will require — teach this list, then use whatever the stem prints:

• Procedure identification and revision
• Part identity, material, specification, and area examined (including datum or weld ID)
• Penetrant type, method, material designations or batch, and dwell
• Removal method and, where applicable, water or emulsifier parameters
• Developer family and developer dwell / evaluation window
• Lighting measurements (UV-A and ambient, or white light) and temperature
• Process-control status for that shift (system-performance piece, lighting check)
• For each recorded indication: location, size (and what was measured — indication vs opening), type (relevant / nonrelevant / false; linear / rounded), and disposition (accept, reject, repair, re-examine)
• Sketch or photograph when the procedure or the customer requires it — especially for rejectable or borderline relevant indications and for specific-exam stems that say "document as required"
• Technician identification, qualification level, and date

"Type" on a report means the classification and shape, not only Type I versus Type II. Location is specific enough that a repair welder can find the site. Size includes units and the measurement rule. A photo that is required and missing is an incomplete examination, not a paperwork afterthought.

Specific-exam crossover: reading a PT procedure paragraph

The 40-item specific exam is not a second copy of capillary-action theory. A typical stem drops a procedure paragraph on the page and asks what the Level II must do. Work it like a closed-book shop traveler.

Example of the kind of paragraph you will see (values are illustrative of how stems are written, not a universal ASNT table):

Liquid penetrant examination shall be Type I, Method C, sensitivity as listed on the approved material. Penetrant dwell 10 minutes minimum. Remove excess penetrant with a clean, dry cloth followed by a cloth slightly moistened with solvent remover; do not spray solvent on the part as the primary removal step. Apply nonaqueous developer. Interpret between 10 and 60 minutes after developer application. UV-A at the surface shall be at least 1000 μW/cm²; ambient visible light shall not exceed 20 lux. Part temperature 50–100 °F. Linear relevant indications longer than 1/8 in (3 mm) are rejectable per the referencing specification.

How a Level II reads that paragraph:

• Type I / Method C / nonaqueous developer / 10-minute dwell / 50–100 °F / stated lighting are essential. Use them. Do not switch to Method A because the hose is closer.
• Solvent is a wipe, not a flood. Spraying the part as the first removal step violates the paragraph even if AMS 2644 lists a spray can.
• Interpretation before 10 minutes or after 60 minutes is outside the window.
• Acceptance is the printed 3 mm linear rule in this stem, not AWS D1.1 from memory and not "any linear is rejectable."
• Report location, the measured length and how it was taken, linear/relevant, and reject if the length exceeds 3 mm. Attach a sketch or photo if that same procedure later requires it.

If a different stem invokes ASME Section V, Article 6 technique plus ASME Section VIII acceptance, you do not import the 3 mm sentence from the example above. You apply the VIII sentence the stem prints. If a stem names AWS D1.1, you apply D1.1. Document crossover is the skill: match the invocation.

Realistic exam scenarios

A Level II shortens Method D emulsifier contact because the line is late. Essential variable changed. The examination is not the approved procedure. Stop and get a Level III / owner disposition; do not "make up time" in the wash.

A candidate treats AMS 2644 as the vessel reject table and fails a 2 mm rounded pore because the penetrant can was sensitivity Level 3. AMS 2644 qualified the can. ASME VIII (or the named spec) decides the pore.

A report lists "PT accept" with no location, no size, no class, and no lighting or temperature. Even if the part is clean, the record cannot be reconstructed. Topic 4 fails the report.

A specific-exam paragraph requires Type I, Method C, and a 10-minute dwell. The candidate runs Type II, Method A, 5 minutes because that is the shop's in-service kit. Wrong examination. The correct answer is to apply the printed essential variables and the named acceptance standard.

Topic 4 rewards document hygiene: know which paper controls materials, which controls technique, which controls acceptance, who is allowed to change the paragraph, and what the report must carry. That is the whole standard's job on this credential.