[Federal Register Volume 77, Number 188 (Thursday, September 27, 2012)]
[Notices]
[Pages 59408-59409]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-23772]
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DEPARTMENT OF HOMELAND SECURITY
Coast Guard
[Docket No. USCG-2012-0804]
Finding of Equivalence; Alternate Pressure Relief Valve Settings
on Certain Vessels Carrying Liquefied Gases in Bulk
AGENCY: Coast Guard, DHS.
ACTION: Notice of availability.
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SUMMARY: The Coast Guard announces the availability of CG-ENG Policy
Letter 04-12, ``Alternative Pressure Relief Valve Settings on Vessels
Carrying Liquefied Gases in Bulk in Independent Type B and Type C
Tanks.'' Existing Coast Guard regulations regarding the allowable
stress factors for type B and type C independent cargo tanks are more
stringent than the International Maritime Organization (IMO) standards
for such cargo tanks. Materials, manufacturing, and inspections have
advanced since the Coast Guard first promulgated regulations on
allowable stress factors on May 3, 1979. CG-ENG Policy Letter 04-12
establishes that for certain type B and type C independent cargo tanks
that are designed and manufactured using advanced techniques, the IMO
standards for allowable stress factors provide a level of safety
protection equivalent to the standards in 46 CFR 154.447 and 46 CFR
154.450.
DATES: CG-ENG Policy Letter 04-12 is effective as of September 27,
2012.
ADDRESSES: This notice and the documents referenced within are
available in the docket and can be viewed by going to
www.regulations.gov, and using ``USCG-2012-0804'' as your search term.
CG-ENG Policy Letter 04-12 is also available at www.uscg.mil and can be
viewed by clicking the link to the Office of Design and Engineering
Standards (CG-ENG) under the ``Units,'' ``USCG Headquarters
Organization,'' and ``CG-5P'' tabs, and scrolling down to ``Policy
Documents.''
FOR FURTHER INFORMATION CONTACT: If you have questions on this notice,
call or email Cynthia A. Znati, CG-ENG-5, U.S. Coast Guard; telephone
(202) 372-1412, email Cynthia.A.Znati@uscg.mil.
[[Page 59409]]
If you have questions on viewing material in the docket, call Renee V.
Wright, Program Manager, Docket Operations, telephone (202) 366-9826.
SUPPLEMENTARY INFORMATION:
Background and Purpose
The IMO first adopted the International Code for the Construction
and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) on
November 12, 1975. The current version of the IGC Code is the 1993
Edition, as amended through December 5, 1996. On May 3, 1979, the Coast
Guard promulgated regulations based largely on the IGC Code, but
adopted the stricter standards of the American Society of Mechanical
Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Section VIII
with respect to allowable stress factors. Coast Guard regulations in 46
CFR 154.447 and 154.450 regarding allowable stress factors for type B
and type C independent cargo tanks have remained unchanged since May 3,
1979.
Coast Guard regulations in 46 CFR 154.447 and 154.450 require that
self-propelled ships carrying liquefied bulk gases in type B and type C
tanks use stress factors that are higher than those in the IGC Code.
The higher stress factors lead to lower maximum allowable relief valve
settings (MARVS) than are allowed by the IGC code. Accordingly, ships
with type B or type C tanks that travel from international waters to
U.S. territorial waters must have two pressure relief valve (PRV)
settings per tank, and they must switch PRV settings upon entering U.S.
territorial waters. We believe that in many cases, switching between
these two PRV settings is not necessary for safety purposes.
Finding of Equivalence
According to 46 CFR 154.32, vessels may meet an alternate standard
if the Commandant determines that the alternate standard provides an
equivalent or greater level of protection for the purpose of safety. We
recognize that advances have been made with respect to materials,
manufacturing, and inspection since we first promulgated 46 CFR 154.447
and 154.450. Therefore, as specified in CG-ENG Policy Letter 04-12 and
below, we have determined that for tanks designed and manufactured with
advanced techniques, the stress factors in the IGC Code provide a level
of safety equivalent to current Coast Guard regulations.
Tanks manufactured consistent with certain conditions are
considered to meet the level of safety required in 46 CFR 154.447 and
154.450. Tanks that meet the following two requirements may use the
MARVS as determined by the IGC Code:
(1) The tank must be designed and built according to the IGC code,
1993 Edition, including all amendments through December 5, 1996; and
(2) The classification society that certified the tank must be
authorized to issue an International Certificate of Fitness for the
Carriage of Liquefied Gases in Bulk (Certificate of Fitness) and must
be authorized to participate in the Coast Guard's Alternate Compliance
Program. See http://www.uscg.mil/hq/cg5/acp/ for further information.
Tanks that do not meet both of these requirements must comply with
current Coast Guard regulations in 46 CFR 154.447 or 154.450.
Alternatively, persons may request approval from the Commandant (CG-
ENG-5, formerly CG-522) to use an alternate pressure relief valve
setting for such tanks. Equivalency requests must include the
information required in 46 CFR 154.32(b) and should also include a copy
of the Certificate of Fitness.
The guidance in this notice and CG-ENG Policy Letter 04-12 is not a
substitute for applicable legal requirements, nor is in itself a
regulation. It is not intended to nor does it impose legally-binding
requirements on any party. It represents the Coast Guard's current
thinking on this topic and may assist industry, mariners, the general
public, and the Coast Guard, as well as other federal and state
regulators, in applying U.S. statutory and regulatory requirements.
This notice is issued under authority of 46 U.S.C. 3703, 46 U.S.C.
9101, 5 U.S.C. 552(a), 46 CFR 154.32, and 33 CFR 1.05-1.
Dated: September 13, 2012.
J.G. Lantz,
Director of Commercial Regulations and Standards, U.S. Coast Guard.
[FR Doc. 2012-23772 Filed 9-26-12; 8:45 am]
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