Interpretation Response #PI-91-031
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Oct 22 1991
Mr. Gary M. Kotara
Vinson & Elkins
The Willard Office Building
1455 Pennsylvania Avenue, N.W.
Washington, DC 20004-1007
Dear Mr. Kotara:
We have considered LFC Pipeline Corporation's petition, dated March 15, 1991, (Pet. No. P-91-1W), which you submitted by letter of the same date. This petition requests waiver of certain welding requirements of 49 CFR 192.243(d)(3) and (f) for a pipeline system in Sutter County, California. The pipeline system transports gas from local wells to two congeneration plants.
It is our policy not to waive compliance with a pipeline safety standard unless compliance would be inappropriate under the circumstances. In addition, we may not waive compliance with a safety standard issued under the Natural Gas Pipeline Safety Act of 1968 (NGPSA) unless we determine the waiver "is not inconsistent with gas pipeline safety" (49 App. U.S.C. 1672 (d)). So in evaluating your first waiver request, we have considered the circumstances that affect compliance and how noncompliance would affect safety. As explained below, we have denied this request.
We also explain below why we consider waivers unnecessary under the circumstances involved in the two other requests. We have neither granted nor denied these requests.
The first waiver request concerns four segments of the pipeline system, which the petition identifies as Areas 1-4. For these segments, the petition requests waiver of the requirement of 192.243(d)(3) to test nondestructively 100 percent of the girth welds within Class 3 locations or highway rights-of-way; or at least 90 percent if 100 percent is impracticable. The petition states that in these four segments, tie-in welds were all x-rayed, but only 30 to 75 percent of the other girth welds were x-rayed.
Of the adverse consequences the petition projects to result from post-construction compliance in Areas 1-4, we regard additional cost and inconvenience to landowners and road users as most likely to occur. But, we do not think these consequences are so onerous that compliance would be inappropriate. They typically occur when long pipeline segments in populated areas are replaced or rehabilitated to meet Part 192 safety requirements. In addition, the projected cost ($280,000) seems overstated, because it includes the cost of hydrostatically testing the affected segments of pipeline. Under Part 192, LFC Pipeline Corporation could x-ray girth welds in the affected segments without additional hydrostatic testing. If x-ray tests reveal a defective girth weld that is repaired later by removing the weld, the short replacement pipe may be hydrostatically tested separately, and tie-in welds need not be hydrostatically tested.
As for the projected adverse consequences of depressurizing the affected segments, Part 192 allows x-ray tests of girth welds that are under pressure. Depressurization would be necessary if LFC Pipeline Corporation removes a defective girth weld. To minimize the impact on customers, such removal could be done after the peak-use season, provided a hazardous leak is not present. 91-10-22.doc 192.243, 192.611
The petition does not persuade us that safety would not be jeopardized by failing to complete all the required x-ray tests in the affected segments. Part 192 requires both hydrostatic testing and nondestructive testing for the safety of these segments. Thus, we cannot conclude the segments are safe merely because they have passed a hydrostatic test. Even a hydrostatic test that exceeds 90 percent of SMYS is not an adequate substitute for x-ray tests of girth welds, because hydrostatic testing is incapable of detecting all unacceptable weld defects that could contribute to weld failure. LFC Pipeline Corporation's alleged low defect rate on x-rayed girth welds is commendable. Yet, if we assume the same rate applies to the girth welds not x-rayed, a probability remains that some unacceptable weld defects exist in the affected segments. We cannot overlook this threat to safety in the affected segments, especially since Areas 1-4 are populated areas or near highways.
Also, 192.611 does not, as the petition asserts, allow operators to uprate pipelines (increase their maximum allowable operating pressures) through hydrostatic testing (see 192.611(a)(3)(ii)). Subpart K of Part 192 governs uprating. Section 192.611 does allow certain existing pipeline segments that were not constructed to Class 3 standards to operate in Class 3 locations if their integrity is confirmed by hydrostatic testing. However, the purpose of this provision is to mitigate the impact of 192.611 on existing pipeline segments that are in satisfactory physical condition. By no means does the provision suggest that such a segment is as safe as if it were constructed to Class 3 standards. Thus, we could not waive 192.243(d)(3) on the basis of this provision of 192.611 and be sure the waiver would not compromise safety.
Second, the petition requests waiver of 192.243(f) to avoid recording the total number of girth welds and the precise location of each girth weld on portions of the system where Part 192 requires nondestructive testing. The petition suggests that LFC Pipeline Corporation could construct a record of the total number of girth welds by estimating the number.
If such a record were constructed properly, we would consider it in compliance with the provision of 192.243(f) regarding the number of girth welds made. Also, 192.243(f) does not require operators to record the precise location of girth welds. Thus, this requested waiver of 192.243(f) is unnecessary.
Finally, the petition requests waiver of 192.243(d)(3) and (f) for portions of the system that LFC Pipeline Corporation believes are now outside the jurisdiction of Part 192, but may come under Part 192 because of land development or change in operation from rural gathering to transmission. Under Section 3(a) of the NGPSA (49 App. U.S.C. 1672(a)), standards affecting construction (such as the welding standards in part 192) do not apply to pipelines existing when the standards are adopted. Because of this provision of the NGPSA, the welding standards in Part 192 do not apply to girth welds existing in rural gas gathering lines that come under the jurisdiction of part 192 after they are put into operation. Thus, this requested waiver of 192.243(d)(3) and (f) is unnecessary.
The petition refers to the subject pipeline system as a gathering system. Our review of the petition, however, suggests that portions of the system may be transmission. Correctly classifying a pipeline as gathering or transmission involves several considerations and affects whether part 192 applies to the pipeline. We suggest, therefore, that LFC Pipeline Corporation discuss this matter with the Chief of our Western Region office. That office is responsible for inspecting gas pipelines in California that do not come under the jurisdiction of the California Public Utilities Commission. The Western Region address is 555 Zang Street, Lakewood, Colorado 80228; phone 303-236-3424.
If you have any recent additional information that bears on the above decisions, please let us know. We will gladly reconsider the petition.
George W. Tenley, Jr.
Associate Administrator for
|§ 192.611||Change in class location: Confirmation or revision of maximum allowable operating pressure|