Interpretation Response #PI-83-0106

Interpretation Response Details

July 14, 1983

Dr. Robert L. Paullin
Associate Director
Office of Operations & Enforcement
Department of Transportation
2100 2nd Street, S.W.
Washington, DC  20590

RE:  D.O.T. Regulations Part 192.179

Dear Dr. Paullin:

Questions have developed on the interpretation of valve spacing under 192.179, and we would like to have an official interpretation, hopefully as soon as possible.  We have a pipeline project going in within several weeks, and the valve spacing questions will be part of the problems with that job.

The opening wording of 192.179 states that each transmission line must have sectionalizing block valves spaced as follows:

Under sub (4) it states that each point on the pipeline in a Class 1 location must be within ten miles of a valve.

A case of ambiguity exists as to whether the actual spacing between valves along a transmission line should be ten, or twenty miles.  As worded under (4) above, it could be construed that if one valve is within ten miles, the requirements have been met.  On the other hand, if the opening wording of 192.179 referring to sectionalizing lock valves it could also be argued that each of the two valves required to sectionalize must be within ten miles of any point on the transmission line.

Please provide our office with an interpretation as soon as possible, in view of our imminent construction work where this will be arising.

 Yours truly,

 A. J. Schellenberg, P.E.
 Lead Gas Engineer

PI-83-0106

No.    83-8          
Date:  August 1, 1983

DEPARTMENT OF TRANSPORTATION

RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION

MATERIALS TRANSPORTATION BUREAU

________________________________________________________________________                                                                  
PIPELINE SAFETY REGULATORY INTERPRETATION
                                                                 

Note: This pipeline safety regulatory interpretation applies to all operators that are subject to the rule under Federal or State law.

SECTION: 192.179

SUBJECT: Valve spacing

FACTS: None.

QUESTION:  How far apart may sectionalizing block valves be placed on an onshore transmission line being constructed in a  Class 1 area?

INTERPRETATION:  Section 192.179(a)(4) provides that "Each point   on the pipeline in a Class 1 location must be within 10 miles of   a valve."  A spacing of not more than 20 miles between valves      will result in each point on the pipeline between valves being within 10 miles of a valve.  This allowable spacing is supported   by the language of the proposed rule (35 FR 5713; April 8, 1970) upon which §192.179 is based, which stated that "Each sectionalizing block valve on a transmission line must be installed at a spacing not to exceed 20 miles within areas conforming to Class 1 Location."

 Richard L. Beam
 Associate Director for
 Pipeline Safety Regulation
 Materials Transportation Bureau

Regulation Sections