Question: With regard to FAQ 274 - Is the operator required to directly examine the entire surface of the carrier pipe within the casing?
Answer: Yes. Under 49 C.F.R. § 192.925, applicable NACE standards, and as discussed in the answer to Gas Integrity Management Program (Gas IMP) FAQ 274, a full, 100% direct examination of the carrier pipe within the casing to ensure that no indications have been missed by any of the indirect inspection tools. Many of these indirect inspection tools cannot see' coating damage or pipe wall loss inside the casings but do infer by their readings that an indication may be located on the carrier pipe somewhere inside the casing. Because many of the indirect inspection tools can not accurately locate nor categorize the specific indication of coating damage or pipe wall loss, a 100% direct examination of the carrier pipe is necessary. As required by NACE RP 0502, section 5.1.2, the direct examination step requires that the operator excavate and expose the pipe surface to make measurements directly on the pipeline. When using the indirect tools on pipe inside a casing, the tools are not capable of accurately locating and characterizing all coating holidays or corrosion defects. Therefore, the entire surface of the carrier pipe in the casing must be directly examined. Direct examination that is limited to the ends of a casing do not assure that the entire pipe inside the casing is free of coating damage or corrosion defects, even if they find an issue near the end of the casing and does not meet § 192.925 requirements for 100% direct examination.