Virginia State Corporation Commission — Pipeline Safety Interpretation

Page 1PI-04-0104 U.S. Department of Transportation Research and Special Programs Administration 400 Seventh St., S.W. Washington, D.C. 20590 April 5, 2004 Mr. Jim Hotinger Senior Utilities Engineer Virginia State Corporation Commission P.O. Box 2118 Richmond, VA 23216 Dear Mr. Hotinger: This is in response to your e-mail of February 10, 2004, in which you request an interpretation of the gas pipeline safety regulations at 49 CFR 192.197(a). You ask whether an external line supplying gas to a pilot controlling the operation of a regulator is a "static" or "control" line within the meaning of the section. Section 192.197(a) states that no other pressure limiting device is required for a distribution system operating at less than 60 psig if the regulator conforms to six requirements. One of these requirements (at § 192.197(a)(6)) is that the regulator is self-contained with no external static or control lines. If there is an external static or control line, another pressure limiting device is required. In an interpretation issued June 29, 1992, the Office of Pipeline Safety (OPS) said that "the 'static or control line' . . . is a line that runs from the regulator to the downstream side of the regulator used to communicate that pressure to the regulator." Under this interpretation, an external line connected to the regulator from the upstream side is NOT a static or control line. However, we have reason to believe that this interpretation was in error. A static or control line is an external line from a regulator that is connected to the main or service line either upstream or downstream and is necessary for the safe functioning of the regulator. A "self-contained service regulator" as used in § 192.197(a)(6) does not require any external line(s) to function correctly or has internal overpressure protection, such as a relief or monitor. Another pressure limiting device is required if a regulator includes external static or control lines and does not have any internal overpressure protection, such as a relief or monitor. If you have any further questions about the pipeline safety regulations, please contact me at (202) 366-4565. Sincerely, Richard D. Huriaux, P.E. Manager, Regulations Office of Pipeline Safety#

Page 2Huriaux, Richard From: Sent: To: Subject: Hotinger, Jim Tuesday, February 10, 2004 11:46 AM Huriaux, Richard Clarification of Interpretation 192.197, No. 13, June 29, 1992. I have printed the full text of the interpretation at the end of this email. I would like a review of this interpretation to explain how a line supplying gas to the pilot controlling the operation of a regulator is NOT “static” or “control” line. The regulator cannot function properly without this pilot which cannot function without the line supplying gas. If this is not a “static” or “control” line, what is it? If this interpretation is accurate, then (as 192.192 stated in part) “…no other pressure limiting device is required.” This could mean that a single failure of this regulator may overpressure the remainder of the service line and the customer’s fuel line. This particular style of regulator may have an “internal monitor” built into it for overpressure protection, but do all regulators with external lines connected to upstream pressure have built in overpressure protection, i.e., and American 1800 CPB2 regulator/ Please let me know your thoughts. Thank you for looking into this matter for me. –Jim Hotinger Interpretation 192.197 13 June 29, 1992 Mr. Ronald J. Boes Manager of Gas Systems Standards & Procedures Indiana Gas Company 1630 North Meridian Street Indianapolis, IN 46202-1496 Dear Mr. Boes: This responds to your letter of April 17, 1992, to Mr. Richard Sanders of the Transportation Safety Institute in which you ask if the 3/8" external line on the Sprague CL34-2 IMR regulator is a "static or control line" as set forth in Section 192.197. The "static or control line" in Section 192.197(a)(6) is a line that runs from the regulator to the downstream side of the regulator used to communicate that pressure to the regulator. The 3/8" external tubing on the Sprague CL34-2 IMR is not a static or control line, but a supply line supplying high pressure gas from the inlet side of the regulator to the pilot to establish the set point; i.e., the outlet pressure of the regulator. I trust that this has adequately responded to your question. Sincerely, Cesar De Leon Director Regulatory Programs Office of Pipeline Safety#