Indiana Gas Company — Pipeline Safety Interpretation

Page 1PI-92-0104 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#

Page 2Mr. Richard E. Sanders Manager, Pipeline Safety Division Transportation safety institute 6500 S. MacArthur Blvd. Oklahoma City, OK 73125 Dear Mr. Sanders: I am seeking information regarding the appropriateness of using the Sprague CL34-2IMR (Internal Monitor) regulator on meter sets without any “other pressure limiting device”. My deliemma is an interpretation of CFR 192.197(6). “A self-contained service regulator with no external static or control lines” and a lack of definition of “external static or contol lines”. The manufacturer of the CL34-2IMR insists, both in their printed literature and verbally, that their unit complies with 192.197. However, the unit (picture attached) does have an external line, 3/8” tubing that loads or controls the pilot regulator. CFT 192.3 Definitions does not include a definition of “static or control lines’ nor can I locate any other definition for control lines within CFR 192. 192.203 gives specific guidelines as to the design of control lines without providing a definition. The “GPTC Guide of Gas Transmission and Distribution Piping Systems” indicates “Control piping is pipe, hydraulically operated control apparatus”. If I accept the definition from the GPTC Guide, the regulator in question could not be used on a meter set without some form of external relief. The manufacturer’s assertion, I believe, is based on the assumption that “control line” refers to a connection downstream. I would appreciate your opinion and /or any knowledge you might have on a past ruling or interpretation by DOT that shed light on this subject. Sincerely, Ronald J. Boes Manager of Gas System Standards & Procedures Indiana Gas Company, Indianapolis, Indiana (317) 321-0575#