Seeking Clarity: NDE Procedure Demonstration Versus NDE Qualification

BY WALTER BEACH, NATIONAL BOARD CONSULTANT, AND JIM WORMAN, NATIONAL BOARD SENIOR STAFF ENGINEER

 

The demonstration of written nondestructive examination (NDE) procedures has been accepted and ex­ecuted for many years in accordance with the ASME Boiler &Pressure Vessel Code. However, in the 2013 Edition, revisions were made to Section V, Article 1, General Requirements, paragraphs T-150 (a) through (c) in an effort to clarify the intent of demonstrating examination procedures. In addition, a new subparagraph (d) was added, which caused general confusion in the industry regarding when procedural qualifications for NDE are required. This article attempts to explain why there is confusion with T-150 paragraph (d) and what might be done in the future to address these concerns.

 

Background

The various Articles of Section V have been revised in the last few years to include a table of essential and nonessential variables (and other details needed for each examination method) in an effort to prepare for the possibility of a referencing code Section invoking a requirement to “qualify” written examination procedures. Though the Articles provide the detailed technical requirements for performing the examinations, there are no guidelines for how the process of procedure qualification should be carried out within the specific Articles. It may have been presumed that the referencing code Section would provide the necessary details whenever making it a requirement to qualify the written examination procedure before its application in code construction.

 

In the 2003 Addenda, Section V added Article 14, Examination System Qualification, for qualifying NDE systems with Manda­tory Appendix 1 of Article 14 being used for the purpose of establishing standard terms and definitions of terms, which appear in Article 14. Article 14 was written to accommodate the ASME Post Construction Standards Committee but it hasn’t been required. It is currently available as API 579-1/ASME FFS-1, which is a fitness for service and evaluation code.

 

The 2013 Edition of Section V provides the qualification model. The minimum technical requirements believed necessary for the qualification of a written NDE procedure are in a new subparagraph (d) under Article 1, T-150.

 

Section V, Article 6, Liquid Penetrant Examination

As an example, in Section V, Article 6, Liquid Penetrant Examination, paragraph T-621.2 begins, “When procedure qualification is specified by the referencing code Section. . .” So, where in the ASME construction code Section is an NDE procedure qualifica­tion specified? To the best of the authors' knowledge, it is not there. Therefore, the requirement for qualifying an NDE procedure must be invoked by the referencing ASME construction code Section. This means that unless the construction code specifically requires NDE procedure qualification, the procedure qualification is not required. If the referencing code Section were to solicit this requirement, perhaps the referencing code Section would provide criteria for qualification of the procedure as well, such as what is expected for a test object, flaw types, sizes, etc.

 

The current 2013 Edition states in paragraph T-150 (d)(2)(a) that “The maximum acceptable flaw size, required flaw orientation, and minimum number of flaws shall be as specified by the referencing code Section.” This further supports that the current ASME codes of construction only require procedure demonstration of T-150(a) and not procedure qualification since the requirements are not specified in T-150(d)(2)(a).

Qualification vs Demonstration

Procedure qualification is not the procedure demonstration as specified in T-150(a). The two terms are not the same as defined by ASME Section V. Mandatory Appendix 1 of Article 1, paragraph I-130, lists terms used in conjunction with Article 1. Following are terms for procedure demonstration and procedure qualification:

 

Procedure demonstration: when a written procedure is demonstrated, to the satisfaction of the Inspector, by applying the examination method using the employer’s written nondestructive examination procedure to display compliance with the requirements of this Section, under

(a) normal examination conditions per T-150(a), or

(b) special conditions as described in T-150(b).

 

Procedure qualification: when a written nondestructive examination procedure is qualified in accordance with the detailed requirements of the referencing code Section.

 

Remember, Section V is not a construction code, but a code that construction codes reference for NDE compliance. At this point in time, no ASME construction code references any NDE procedures to be qualified.

 

Here is an example of how ASME Section VIII, Division 1, Mandatory Appendix 6, Methods for Magnetic Particle Examination, makes reference to T-150 of Section V:

6-1 Scope

(c) Magnetic particle examination shall be performed in accordance with a written procedure, certified by the Manufacturer to be in accordance with the requirements of T-150 of Section V.

It is clear that the current ASME non-nuclear construction codes do not contain a specific reference to procedure qualifica­tion with the required specified details of T-150 (d)(2)(a). At the surface, it appears all of T-150 has been imposed, but without the specific details (such as test object, flaw type, size, etc.), procedure qualification is not possible.

 

Qualifying Personnel

If one reads Article 1, paragraph T-120 (g), in order to get a better understanding, he or she would come to the conclusion that personnel demonstration is required.

T-120 General

(g) When the referencing Code Section does not specify qualifications or does not reference directly Article 1 of this Section, qualification may simply involve a personnel  demonstration to show that the personnel performing the nondestructive examinations are competent to do so in accordance with the Manufacturer’s established procedures.

 

Article 1, paragraph I-130, defines personnel demonstration as:

Personnel demonstration: when an individual displays an understanding of the examination method and proficiency in conducting the examination, by performing a demonstration examination using the employer’s written non destructive examination procedure.

The construction codes are requiring personnel demonstration, but require that the manufacturer (certificate holder) certify that the written procedure (not personnel) be in accordance with T-150 of Section V regarding procedure demonstration.

The Section V committee has made the changes as indicated above, but the construction code committees have yet to respond to the impact of these changes, which has caused this general confusion in the industry. Until there is further clarification from the Section V Committee through interpretations or rewrites, it appears that T-150, paragraph (d) is not applicable to the current construction codes.

 

 

Source: FALL 2014 NATIONAL BOARD BULLETIN