# Office of Florida State Fire Marshal — Pipeline Safety Interpretation

- **operation:** document
- **citation:** PI-75-004
- **title:** Office of Florida State Fire Marshal — Pipeline Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 1975-01-24
- **effective on:** Not available
- **summary:** PI-75-004 response to Office of Florida State Fire Marshal concerning 192.503.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-75-004.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-75-004.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-75-004
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1975/PI75004.pdf
**body:**

<<<PAGE 1>>>

January 24, 1975
Mr. Olin L. Greene, Director
Division of State Fire Marshal
Office of Florida State Fire Marshal
Larson Building
Tallahassee, FL 32304
Dear Mr. Greene:
This acknowledges your letter of January 20, 1975, providing information on the use of liquefied
petroleum gas (LPG) as a test medium.
The January 20 letter and your letter of November 15, 1974, requesting that we interpret 49 CFR
192.503(b) to permit the use of LPG as a test medium, are accepted as a petition to change that
rule.
This matter is assigned Docket No. Pet. 75-1. Please refer to this number in future
communications on the subject.
We will review the petition to determine whether it warrants beginning a rule-making action. At
the conclusion of our review, we will notify you whether the petition for rule making is granted or
denied.
Sincerely,
Joseph C. Caldwell
Director
Office of Pipeline Safety
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<<<PAGE 2>>>

January 20, 1975
Mr. Joseph C. Caldwell, Director
Office of Pipeline Safety
Department of Transportation
Washington, D.C. 20590
Dear Mr. Caldwell:
In your letter of December 16, 1974, you offered your help in supporting our contention
that petroleum gas used as a test medium would pose no greater hazard to the public than natural
gas. In reference thereto the following is offered for consideration in allowing liquefied petroleum
gas to be used as a test medium for pipelines:
Section 192.503 (b) allows:
1. Liquid:
The use of liquid would be contrary to safe practices because the drying of piping
after testing is impractible [sic] and at best would leave some liquid residue.
2. Natural Gas:
Natural gas would not be available where LP gas piping is installed and even if it
were, natural gas contains some of the same properties found in liquefied
petroleum gas.
3. Inert Gas:
Inert gas would require purging the system to the atmosphere or burning; either
would present certain hazards that would be negated if LP gas was used. Also,
inert gas would not be odorized, whereas LP gas would be.
Following are some reasons why LP gas would offer the best test medium for
public safety:
1. 2. The density of LP gas is greater than other gases and would tend to show a leak as
opposed to gases of lesser density.
LP gas has a more narrow range of flammability than natural gas. LP gas, 2.4% -
9.5% gas to air. Natural gas, 5.3% - 14.0% gas to air. Therefore, offering less
probability of remaining in the explosive range.
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<<<PAGE 3>>>

Page 2
3. The technical gas safety information available to this writer suggests that any
pipeline should be tested with
the product to be used as the most practical way to assure leak detection.
4. LP gas pressures are relatively low in relation to natural gas transmission systems;
therefore, LP gas tests would minimize the possibility of over-pressure as to
system design.
Your assistance in this matter is sincerely appreciated and if you have any
questions or if we can be helpful to you in any manner, please let us know.
Sincerely,
THOMAS D. O'MALLEY
STATE TREASURER
STATE FIRE MARSHAL
Olin L. Greene, Director
Division of State Fire Marshal
dal\192\503\75-01-24
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<<<PAGE 4>>>

December 16, 1974
Mr. Olin L. Greene, Director
Division of State Fire Marshal
Office of Treasurer
Insurance Commissioner
Tallahassee, FL 32304
Dear Mr. Greene:
This responds to your letter of November 15, 1974, requesting that we interpret 49 CFR
192.503(b) to permit the use of petroleum gas as a test medium.
Section 192.503(b) prohibits the use of petroleum gas as a test medium by exclusion from the list
of permissible media. Consequently, this section cannot be interpreted to permit the use of
petroleum gas.
We would be happy, however, to treat your letter as a petition to change the rule, if you will
provide us further information to support your contention that petroleum gas as a test medium
poses no greater hazard to the public than natural gas.
Sincerely,
Joseph C. Caldwell
Director
Office of Pipeline Safety
dal\192\503\75-01-24
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<<<PAGE 5>>>

November 15, 1974
Joseph C. Caldwell, Director
Office of Pipeline Safety
Department of Transportation
Washington, D.C. 20590
Request for an Interpretation on
Title 49-192.503(b) _
Dear Mr. Caldwell:
The test medium must be a liquid, air, natural gas, or inert gas that is:
1. 2. 3. Compatible with the materials of which the pipeline is constructed.
Relative free of sedimentary materials
Except for natural gas, nonflammable.
We feel that when the standards were written, the use of LP Gas as a test medium was
possibly overlooked.
In Florida, the State Fire Marshal's Office has permitted the use of LP Gas as a test
medium and has had no accidents as a result of its use.
The LP Gas systems are small in comparison to natural gas transmissions and distribution
systems and pipe size rarely exceeds two inches in diameter, therefore limiting the quantity of gas
needed for a test. The LP Gas companies, as a rule, do their own piping and normally do not
have access to an air compressor for pressuring the pipe.
We feel that the use of LP Gas as a test medium would constitute no more of a public
safety hazard than the use of natural gas. We request that an interpretation be rendered
permitting its use.
If we can be of assistance in any manner please let us hear from you.
Sincerely,
THOMAS D. O'MALLEY
STATE TREASURER
STATE FIRE MARSHAL
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Olin L. Greene, Director
Division of State Fire Marshal
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