Heath and Associates — Pipeline Safety Interpretation

Page 1Mr. Charles C. Heath Heath and Associates P. O. Box 185 7 North Lafayette Street Shelby, North Carolina 28150 Dear Mr. Heath: You have requested our opinion whether a monitoring-type regulator station that includes a by- pass line with a lockable valve meets the design requirements of 49 CFR Part 192. James Stites of the South Carolina Public Service Commission, anticipating your request, has sent us copies of correspondence with you related to an incident in which an individual opened such a by-pass line, causing a downstream main to rupture. We have concluded from our review of applicable regulations that regulator stations designed as you have described are permissible under Part 192. Moreover, we do not believe that the intent of the regulations requires installation of a non-isolatable relief device in these stations to provide further protection against downstream overpressure. The purpose of the regulations that govern the control of pressure at regulator stations is to protect against accidental overpressure caused by failure of a piping component. The regulations are not intended to require the installation of hardware to guard against potential overpressure caused by human error, such as opening a by- pass valve without regard for the consequences. Our experience shows that in most cases the best regulatory approach to preventing pipeline accidents caused by human error involves requiring personnel to follow detailed operating and maintenance procedures and to undergo training and testing in those procedures. We have rulemaking proceedings underway in both areas. Sincerely, George W. Tenley, Jr. Director Office of Pipeline Safety DB C:\WP51\INTERPRT\192\199\90-02-22 1#