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Interpretation Response #PI-92-0104 ([Indiana Gas Company] [Mr. Ronald J. Boes])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Indiana Gas Company

Individual Name: Mr. Ronald J. Boes

Location State: IN Country: US

View the Interpretation Document

Response text:


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.


Cesar De Leon
Regulatory Programs
Office of Pipeline Safety

Mr. 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 control 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.


Ronald J. Boes
Manager of Gas System
Standards & Procedures
Indiana Gas Company,
Indianapolis, Indiana
(317) 321-0575

Regulation Sections

Section Subject
192.197 Control of the pressure of gas delivered from high-pressure distribution systems