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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #PI-79-0101

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

Interpretation Response Details

Response Publish Date:

Company Name:

Individual Name:

Location State: AZ Country: US

View the Interpretation Document

Response text:

Arizona Corporation Commission
2222 West Encanto Blvd. Phoenix, Arizona 85009

February 23, 1979

Mr. Howard Hersey
Arizona Public Service Company
P.O. Box 21666
Phoenix, AZ 85036

Dear Mr. Hersey:
In regards to my interpretation regarding over pressure protection requirements and grandfathering,
clarification has been received from DOT, Washington. My interpretation has been substantialized.
Please see the enclosed copy of the letter from Cesar DeLeon dated February 14, 1979.

As a result of this clarification, please review all pressure regulating stations in Arizona Public
Service's systems and make the corrections necessary to comply with over pressure protection
requirements as soon as possible.

Please acknowledge receipt of this letter and inform this commission of your proposed program
schedule for accomplishment of the review mentioned above and correction of deficiencies found
resulting from review and this clarification.
Sincerely,
ARIZONA CORPORATION COMMISSION H. R. Garabrant, P.E.
Utilities Safety Engineer
Utilities Division

Arizona Corporation Commission
2222 West Encanto Blvd.
Phoenix, Arizona 85009

February 23, 1979

TO:                    All Gas Operators - State of Arizona

FROM:              H.R. Garabrant, P.E. SUBJECT:         Over pressure protection

As you are all aware, this commission has been enforcing the over pressure protection requirements
when required, regardless of age of the installation, i.e. grandfathering of 192.195 is not
applicable as parts
192.619(b) and 192.621(b) are not grandfathered and part 192.195 is incorporated by reference in
192.619(b)
and 192.621(b).

One company disagreed with our enforcement policy and it was necessary to obtain clarification from
Washington to substantiate this position.

Substantiation of the interpretation has been received and a copy of the letter stating the facts
is enclosed, as it may be of interest to you.

Sincerely,
ARIZONA CORPORATION COMMISSION
H. R. Garabrant, P.E.
Gas Utilities Safety Engineer
Utilities Division

Department of Transportation
Research and Special Programs Administration
Washington, D.C. 20590

February 14, 1979

H. R. Garabrant, P.E.
Gas Utilities Safety Engineer
Utilities Division
Arizona Corporation Commission
2222 West Encanto Boulevard
Phoenix, Arizona 85009

Dear Mr. Garabrant:

This responds to your letter of October 20, 1978, regarding the applicability of sections
192.619(b) and
192.621(b).

Your letter notes that sections 192.619(b) and 192.621(b) are operation requirements which are not
"grandfathered" and are continuing regulations that are applicable to all pipelines. Your letter
mentions that both of these sections reference section 192.195 which states, in part, that " . . .
must have pressure relieving or pressure limiting devices that meet the requirements of sections
192.199 and 192.201." As you noted, sections 192.195, 192.199, and 192.201 are design requirements
which only apply to pipelines readied for service after March 12, 1971, or replaced, relocated, or
otherwise changed after November 12, 1970. You inquire if you are correct in interpreting that all
district regulators including those readied for service before March 12, 1971, must meet the
requirements of section 192.621(b).

Because section 192.195 is incorporated by reference in sections 192.619(b) and 192.621(b), which
are operating requirements, the provisions of section 192.195 apply to those pipelines readied for
service before March 21, 1971, if section 192.619(b) or section 192.621(b) applies to the pipelines
concerned.
We trust that this adequately responds to your inquiry. Sincerely,
Cesar De Leon
Associate Director for Pipeline Safety Regulation
Materials Transportation Bureau

UNITED STATES GOVERNMENT DEPARTMENT OF TRANSPORTATION
RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION Memorandum

DATE:               December 19, 1978

Subject:           Request for Interpretation

From:               Chief, Western Regional Office

To:                    Associate Director, Office of Operations and Enforcement

Attached is a copy of Mr. Garabrant's letter to you requesting an interpretation.

This is the letter we discussed that was sent by you to OPSR for interpretation and was misplaced.

Please resubmit to OPSR for immediate action as Mr. Garabrant is anxious to receive the
interpretation. Thank you.

Jack Overly

Arizona Corporation Commission
2222 WEST ENCANTO BLVD.
PHOENIX. ARIZONA SSOOS

October 20, 1978

Mr. Robert L. Paullin Associate Director for Operations and Enforcement
Materials Transportation Bureau Department of Transportation Washington, D.C. 20590

Dear Mr. Paullin:

In the past one area of enforcement that I have given a rather high priority to in this state and
one that all companies have been making corrections to comply with has been 192.621(b).

"No person may operate a segment of pipeline to which paragraph (a)(5) of this section applies,
unless over pressure protection devices are installed on the segment in a manner that will prevent
the maximum allowable operating pressure from being exceeded in accordance with section 192.195."

Paragraph (a)(5) states. "The pressure determined by the operator to be the maximum safe pressure
after considering the history of the segment, particularly known corrosion and the actual operating
pressures."

The above statements are basically repeated in paragraph 192.619 (b).

You will note that section #192.621 and 192.619 are in the regulations under sub-part L. -
operations. Interpretations are that this sub-part and sections are applicable to all pipelines
regardless of age i.e. not grandfathered (see attached chart).

Part 192.619 (b) and 192.621 (b) both refer to 192.195.

Part of the requirements of 192.195 include, "-----must have pressure relieving or pressure
limiting devices that meet the requirements of sections 192.199 and 192.201."

I will not repeat 192.199 here but in paragraph (g) of 192.199 there is a clause "be designed and
installed to prevent any single incident such as an explosion in a vault or damage by a vehicle
from affecting the operation of both the over pressure protective device and the district
regulator. "

192.201 (b) reads "When more than one pressure regulating or compressor station feeds into a
pipeline, relief valves or other protective devices must be installed at each station to insure
that the complete failure of the largest capacity regulator or compressor or any single run of
lesser capacity regulators or compressors in that station will not impose pressure on any part of
the pipeline or distribution system in excess of those for which it was designated or against which
it was protected, whichever is lower."

You will note that sections 192.195 192.199 and 192.201 are in sub-part D - This section is
grandfathered and it might be possible to interpret that old regulator stations need not be up
dated to include over pressure protective devices at each station.

My interpretation has been and I still consider it a defficiency if each district regulator station
does not have an over pressure protective device and that a device must be added. This is based on
the paragraph 192.621 (b), and is the more stringent condition due to "no person may operate-----.”
One major company is faced with a fairly major effort to correct a considerable number of stations.
They have
stated that they believe that the regulations exceed the authority given by Congress and that there
was no
intent by Congress for an operations requirement to require rebuild or adding to existing
facilities as Congress
"grandfathered" design and construction.

I might mention that most of this company's stations feed into various integrated systems and in
most cases there is a relief valve some where in the system. I suggested a while back that they use
the waiver procedure showing the calculations to prove (under minimum load conditions) that the
MAOP would not be exceeded by the allowable amount if any one of the district regulator stations
should fail. Such situations would have to be well documented before I would consider a waiver
approval. I doubt that this would solve many of their problems as there is a certain amount of
pressure gradient involved and a remote relief valve would have to
be set lower than normal to prevent over pressuring lines close to the failing regulator station.

Before I bring the situation to the attention of the Arizona Corporation Commissioners for show
cause action possibly involving fines. I need confirmation from your office that my interpretation
is correct and that the Legal Department in Washington confirms that the requirements of 192.621
(b) is in compliance with Congressional intent.

I would appreciate a reply as soon as possible on this.

NOTE: To put things in the proper perspective, I have not been citing companies where the paragraph
192.199 (g) is in violation as long as 192.201 (b) was in compliance and the equipment installation
grandfathered due
to age. This is what I think the rules and Congress intended.

I don't see that the requirement of adding a relief valve or monitor regulator is any more out of
line than adding cathodic protection requirements to older facilities that would otherwise be
grandfathered.

Sorry to put you to this trouble but I need a certain amount of backup before I present this to the
Commission for action. Hopefully, if your answer confirms my interpretation, the company may
accelerate their program in this regard and formal Commission action with the usual public hearings
avoided.
Sincerely,
ARIZONA CORPORATION COMMISSION H. R. Garabrant, P.E.
Gas Utilities Safety Engineer
Utilities Division

Regulation Sections