Pipeline Safety Interpretation PI-81-0103

Page 1PI-81-0103 The American Society of Mechanical Engineers United Engineering Center 345 E. 47th St. New York, N.Y. 10017 April 24, 1981 Mr. William Gute Petroleum Engineer Pipeline Safety Enforcement Division Office of Operations & Enforcement Materials Transportation Bureau Dept. of Transportation Research and Special Program Admin. SUBJECT: Inquiry 1453 Dear Mr. Gute: Reference is made to your inquiry letter of February 5, 1980. Our understanding of the question in your inquiry and our reply are as follows: 1. QUESTION: What are the definitions of "designer",”special or unusual problem", and "rigorous analysis" as mentioned in Paragraph 400 (e) of ANSI/ASME B31.4. REPLY: Designer. The responsible person who, by the use of his knowledge, training, expertise, and experience, applies accepted engineering practice and criteria to arrive at the specific physical combination of pipe, fittings, structures, and materials meeting the requirements of this Code. Special or Unusual Problem. A problem relating to the general subject of this Code, but not specifically covered by procedures or limitations detailed therein. Rigorous Analysis. A comprehensive and detailed investigation and/or assessment of a subject where specific rules are not given in the Code, or as a substitute for the simplified engineering approach usually presented in the Code. When used, the designer is responsible for demonstrating the validity of his approach. 2. QUESTION: Is it the intent of Section 400 (e) of the B31.4 Code to allow pipeline operators to exceed flange or valve designer/ manufacturer's maximum working pressure based on the operators own testing or calculations? REPLY: ANSI/ASME B31.4 clearly states that when a designer/operator exceeds or deviates from the requirements of the Code, based on a rigorous analysis, he alone is responsible for demonstrating the validity of his approach. I trust the above comments have adequately answered your questions, and I shall consider the matter closed unless I hear from you to the contrary. Sincerely, Jerry D’Acanzo Secretary, B31#