Tennessee Public Service Commission — Pipeline Safety Interpretation

Page 1Mr. John S. Searcy, Director Engineer Division Tennessee Public Service Commission Cordell Hull Building Nashville, Tennessee 37129 Dear Mr. Searcy: This responds to you letter of February 20, 1975, asking whether the incorporation by reference of MSS-SP-25 un 49 CFR 192.63 includes the document MSS-SP-63 to the extent that it is incorporated by reference in Section 18 of MSS-SP-25. The reference to MSS-SP-63 in Section 18 of MSS-SP-25 incorporates a portion of MSS-SP-63 essential to the basic document MSS-SP-25. To the extent that MSS-SP-63 is incorporated by reference in MSS-SP-25, it is also incorporated in 49 CFR 192.63. Sincerely, /Signed/ Joseph C. Caldwell Director Office of Pipeline Safety DB C:\WP51\INTERPRT\192\63\75-03-24 1#

Page 2Mr. Joseph Caldwell Dept. of Transportation Office of Pipeline Safety 2100 2nd Street, SW Washington, D. C. 20590 Dear Mr. Caldwell: Regulation 192.63(a) states that "Except as provide in paragraph(d) ... each valve, fitting, length of pipe, and other component must be marked as prescribed in-(1) The specification to which it was manufactured; or (2) MSS...SP-25." Section 18 of MSS SP-25 states "Fittings for use in gas transmission and distribution system...(18.1) Markings for these fittings shall be those shown in MSS SP-63." 192.63 does not specifically reference MMS SP-63, which, from the title, applies only to high strength wrought welding fittings. It is a correct interpretation that MSS SP-63 is not automatically incorporated, and that MSS SP-25, not MSS SP-63, would govern the marking of fittings for use in gas transmission and distribution? Sincerely, John S. Searcy, Director Engineering Division DB C:\WP51\INTERPRT\192\63\75-03-24 2#