# Shell Oil Company — Pipeline Safety Interpretation

- **operation:** document
- **citation:** PI-71-061
- **title:** Shell Oil Company — Pipeline Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 1971-07-08
- **effective on:** Not available
- **summary:** PI-71-061 response to Shell Oil Company concerning 195.106.
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- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1971/PI71061.pdf
**body:**

<<<PAGE 1>>>

July 8, 1971
Mr. R. L. Brown
Plant Manager
Shell Oil Company
One New Street
Fall River, Massachusetts 02722
Dear Mr. Brown:
An examination of information reported on the accident form filed in connection with the accident on
January 29, 1971, in Waltham, Massachusetts, revealed two possible violations of the liquid pipeline
safety regulations contained in Part 195.
The first concerns the design pressure which was reported under Item M to be 2407(?) psig. 195.406 establishes the maximum allowable operating pressure for liquid pipelines. Section
This section, which
became effective on January 8, 1971, sets the limit on operating pressure for pipelines in existence on
January 8, 1971, to be the lesser of two pressures:
• The internal design pressure of the pipe determined in accordance with Section
195.106, or
• The design pressure of any other component of the pipeline.
Calculating the internal design pressure by the formula contained in Section 195.106, for 6-inch pipe
with 0.250 inch wall thickness and made of Grade B material, gives an internal design pressure of 1902
psig based on a same joint factor of 1.00.
The second concerns the patrol interval. The length of time between patrols on this pipeline was
reported in Item J to be monthly. Section 195.412(a) requires each carrier to inspect the surface
condition on or adjacent to each pipeline right-of-way at least every two weeks.
Please provide this office with the explanation of this apparent noncompliance with the liquid pipeline
safety regulations. Your prompt response to this request will be appreciated.
Sincerely,
Joseph C. Caldwell
Acting Director
Office of Pipeline Safety
dal/195.106
71-07-08
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