The hazardous liquid pipeline regulations (and gas regulations as well) allow for repair of welds during construction and specifies how the repairs are to be made. While full encirclement sleeves are allowed for weld repairs for operating pipelines, they are not allowed during the construction process.
This difference is further explained in the following interpretation from 1986.
Interpretation 195.230 6
August 21 1986
Mr. R. E. Penderson
Mid-America Pipeline Co.
1800 South Baltimore Ave.
Post Office Box 645
Tulsa, Oklahoma 74101-0645
Dear Mr. Penderson:
Your letter of July 16, 1986, requests that we amend Part 195 to permit the use of encirclement sleeves as a repair method for defective welds in operating pipelines. Your letter indicates that ANSI B31.4 permits their use as an acceptable repair method in either maintenance or construction.
The regulation governing the repair of hazardous liquid pipelines in operation is §195.422. This regulation does not disallow the use of encirclement sleeves to repair defects in operating pipelines, including weld defects.
Part 195 does not, however, permit the use of encirclement sleeves to repair weld defects discovered during construction. These defects must be removed or repaired in accordance with the requirements of §195.230.
In our view, ANSI B31.4 does not differ from Part 195 regarding the permissibility of using encirclement sleeves to repair weld defects. Their use is permitted by section 451.6 as an allowable repair method for weld defects in operating pipelines, but not weld defects in pipelines under construction. These latter weld defects are required by section 434.8.7(b) to be repaired according to API Standard 1104, which in section 7 sets forth specific weld removal and repair standards that do not include the use of encirclement sleeves.
Since Part 195 does not prohibit the use of encirclement sleeves to repair weld defects in operating pipelines, there is no need for an amendment to permit such usage. Also, since the B31.4 code does not permit the use of sleeves for weld repair during construction, there does not appear to be an adequate basis for changing Part 195 to permit their use in this respect.
Robert L. Paullin
Office of Pipeline Safety
MID-AMERICA PIPELINE COMPANY
16 July 1986
U.S. Department of Transportation
Office of pipeline Safety
400 7th Street SW
Washington, DC 20590
Attention: Dr. Robert Paullin
Dear Dr. Paullin:
Mid-America Pipeline Company is in the business of transporting primarily highly volatile liquids, that is natural gas liquids and anhydrous ammonia. In following the approved weld repair method as described in Part 195.230 “Repair or Removal of Defects” and Part 195.422 “Pipeline Repairs” the operator of “in service” pipelines is required, when repairing defective welds that require the removal of a cylinder of pipe including the weld, to set “stopples” or otherwise evacuate the pipeline. This unnecessarily exposes employees to the product vapors and in the case of anhydrous ammonia requires that the work be performed while wearing gas mask or other breathing apparatus.
For the reason summarized above, Mid-America Pipeline Company does hereby petition the Commission to revise Part 195 by adding the repair procedure as described in ANSI B31.4 as an acceptable repair method in either maintenance or construction. That is, the application of a complete encirclement sleeve over the defective weld when found in an operating pipeline. This, we believe, will satisfy the intent of Part 195 to protect the public as well as the operators employees and will provide an additional repair procedure that is currently accepted as proper and safe.
R. E. Penderson
All this and more in WinDOT, The Pipeline Safety Encyclopedia.