NOTE: This Interpretation was previously assigned as 15-09.

Subject: Part 3, Section 3

Edition: 2013

Question 1: May installation of a flush patch in a pressure retaining part be classified as a “Repair” if any of its attachment welds are made using a backing strip along with the welds receiving the same degree of volumetric examinations as original construction when the original vessel design and construction of the pressure retaining part did not use backing strips in its design and construction?

Reply 1: No.  If backing strips were not considered and used in the original design and construction, and are used on the flush patch installation, the work must be classified as an Alteration.

Question 2: May installation of a flush patch in a pressure retaining part be classified as a “Repair” if any of its attachment welds are made using a backing strip along with the welds receiving a lesser or higher degree of volumetric examination such that the applicable flush patch butt weld design joint efficiency is lower or higher than original construction when the original vessel design and construction of the pressure retaining part did not use backing strips in its design and construction?

Answer 2: No.  If backing strips were not considered and used in the original design and construction, and are used on the flush patch installation, and if the applicable joint efficiency of the weld made using a backing strip is lower or higher than that of the joint efficiency used on the original design, there would be a change in the joint efficiency applicable to design of the part which would mandate that the work be classified as an Alteration.

Question 3: If a flush patch plate in a pressure retaining item (PRI) is installed with attachment welds using backing strips and the attachment welds receive the same or higher degree of volumetric examination required by the original code of construction with no reduction in joint efficiency as original construction is this considered a repair?

Answer 3: Yes

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Subject: Part 3, Section 4

Edition: 2013

Question: When the Inspector and, when required, the Jurisdiction agree that penetrant examination will provide meaningful results to verify the integrity of a weld repair, may penetrant examination of the repair be performed in lieu of a hydrostatic test?

Reply: Yes.

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Subject: Part 3, 1.6.1

Edition: 2013

Question 1: In an “R” Certificate Holder’s Quality Control system, is it permissible for one individual to have dual responsibilities for management functions, such as Quality control functions and non-quality control functions, such as production?

Reply 1: Yes, provided there is no conflict in enforcement of the quality control system and the functional responsibilities and duties are clearly described in the quality control manual. 

Question 2: Is approval of revisions to the Quality Control Manual permitted to be made by someone other than the individual designated in the manual as responsible for approval of the revisions?

Reply 2: No.

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Subject: Part 3, 3.3.3 s) and 3.3.4.3 a)

Edition: 2013

Question: When performing weld metal buildup of wasted areas of pressure retaining items, is the wall thickness required to be restored to the thickness listed on the Manufacturers Data Report?

Reply: No. The minimum thickness after build-up shall be the original thickness of the pressure retaining item minus the corrosion allowance. 

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Subject: Part 3, 2.5.2

Edition: 2013

Question 1: An R-Certificate holder decides to perform post weld heat treatment (PWHT) of a vessel at the request of a client, where no PWHT was performed in the original construction. Is the performance of PWHT of the vessel considered an alteration and subject to documentation using a Form R2? 

Reply: Yes.

Question 2: For the vessel described above, must the weld procedures used for construction of the vessel be qualified with PWHT?

Reply: Yes.

Question 3: Must the PWHT described above be performed by the R-Certificate holder? 

Reply: No, the PWHT may be subcontracted; however the R certificate holder retains the responsibility for the performance of the PWHT. 

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Subject: Part 1, 3.8.2.3

Edition: 2013

Question: Is it permissible to place the operating temparture control on a storage tank located in a hot water supply system?

Reply: Yes.

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Subject: Part 3, 3.3.2 e)

Edition: 2013

Question: Is seal welding of inspection opening covers, such as handhole plates or plugs, considered a routine repair?

Reply: No.

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