Pipeline Safety Interpretation PI-77-0104

Page 1PI-77-0104 Mr. Jim Barton Williams Brothers Engineering Company Tulsa, Oklahoma 74136 Mr. Barton said they needed an interim response by phone to their letter of February 25, 1977, since they had to relay the information to Australia. I gave him the following guidance on each specific question: a) Basis for the number of buildings for class 1 and 2 locations. How were the numbers 10 or less buildings for class 1 and 46 or less buildings for class 2 locations arrived at? Answer: This requirement was taken from the industry developed standard B31.8. we do not know the basis for these numbers. b) What is the interpretation of “normal use” as used in defining class locations? What frequency of use of a building or defined outside area by more than 20 people would require the location to be classified3, once a day, week, month, year? Answer: I told him that “normal use” should be interpreted to be based on the frequency of used of playgrounds, outdoor theaters, and recreation areas. I read him the interpretation in the November 1977 Advisory Bulletin. I also told him that a cemetery had been interpreted not to require a class 3 location; while a church would require a class 3 location. I told him we would send him a copy of the November 1976 Advisory Bulletin. c) What is the interpretation of “intended for human occupancy” as used in 192.5? Answer: “Human Occupancy” probably meant dwelled in or inhabited or occupied by people for a significant part of a day. I told him a more definitive interpretation for all three questions would follow. Cesar DeLeon Acting Director Office of Pipeline Safety Operations#