Middle Tennessee Natural Gas — Pipeline Safety Interpretation

Page 1Mr. Stephen C. Stinson Middle Tennessee Natural Gas Utility District P. O. Box 231 Smithville, TN 37166 Dear Mr. Stinson: Than you for your letter to Mr. Frank Fulton of February 12, 1974. In response to the questions you ask, we offer the following: Question: In section 192.63 you say each piece of pipe must be marked. What happens when this is covered by coating? Answer: The intent of the regulation is that the product, pipe, fitting, etc., be clearly identified from point of manufacture to installation. Where pipe is coated before installation, covering the marking, the coated pipe must be remarked unless some other means of identification permitted by section 192.63 is used. Question: If the specifications of the pipe are listed on the bill of lading and the original purchase order, is a blanket identification sufficient? Answer: A blanket identification where permitted under section 192.63 is sufficient only if the items involved are clearly identified from point of manufacture to installation, as when all items so identified are used at a single installation. Where individual items covered by a blanket identification are used separately, each item must be marked exclusive of the blanket identification. Question: How have people maintained marking that was put on the coating? As you know, ultra violet light attacks PVC and ink on it. Do you require identification to be maintained on coal tar? If so, how do you identify field coated pipe? Answer: For coated pipe in short term storage or protected storage , a marking on the coating or coating wrapper will normally remain legible until installation. For coated pipe in long term storage, marking is usually maintained by painting the pipe inside each end. Also, some operators paint a color code on pipe. It is an operator's responsibility to use markings that will identify material until it is installed. Section 192.63 does not require that markings be maintained after installation, but materials used in any segment of pipeline must be identifiable for the life of the DB C:\WP51\INTERPRT\192\603\74-03-18 1#

Page 2facility to ensure proper operation and maintenance. This is accomplished by maintaining appropriate records. We hope that his sufficiently answers your questions. If we may assist further, please let us know. Sincerely, /signed/ Joseph C. Caldwell Director Office of Pipeline Safety DB C:\WP51\INTERPRT\192\603\74-03-18 2#

Page 3February 12, 1974 Mr. Frank Fulton, Chief Engineer Office of Pipeline Safety Department of Transportation Washington, D. C. 20590 Dear Frank: Really enjoyed your discussion in Nashville but I have a few questions concerning marking. 1. In section 192.63 you say each piece of pipe must be marked. What happens when this is covered by coating? 2. If the specifications of the pipe are listed on the bill of lading and the original purchases order, is a blanket identification sufficient? 3. How have people maintained marking that was put on the coating? As you know, ultra violet light attacks PVC and ink on it? Do you require identification to be maintained on coal tar? If so, how do you identify field coated pipe? Your comments would be appreciated. Sincerely, MIDDLE TENNESSEE UTILITY Stephen C. Stinson DB C:\WP51\INTERPRT\192\603\74-03-18 3#