USCG Issues Policy Letter

U.S. Coast Guard
Monday, August 13, 2012

Subj: ALTERNATE PRESSURE RELIEF VALVE SETTINGS ON VESSELS CARRYING LIQUEFIED GASES IN BULK IN INDEPENDENT TYPE B AND TYPE C TANKS.
 

Ref:
 

(a) International Code for the Construction and Equipment of Ships Carrying Liquefied
Gases in Bulk, 1993 Edition (IGC Code)
(b) Title 46 Code of Federal Regulations (CFR) Part 54
(c) Title 46 Code of Federal Regulations (CFR) Part 154
(d) American Society of Mechanical Engineers (AMSE) Boiler and Pressure Vessel
Code (BPVC) Section VIII

 

1. PURPOSE. To provide policy for alternate pressure relief valve settings for ships carrying liquefied gases in bulk in independent type B and type C tanks.

 

2. ACTION. USCG Headquarters Units and Offices and Districts and Sector Commanders shall use the guidance in this policy letter to ensure compliance with U.S. statutory and regulatory requirements.

 

3. DIRECTIVES AFFECTED. This policy will be reflected in a subsequent regulatory update to applicable U.S. regulations.

 

4. BACKGROUND. The IGC Code, reference (a), specifies lower stress factors for Type B and Type C tanks than the requirements in references (b) and (c). As a result, all ships carrying liquefied gases in bulk entering the navigable waters of the United States must use lower maximum allowable relief valve settings (MARVS) on Type B and C tanks than required by the IGC Code. Therefore vessels operating in US and international waters opt to have two pressure relief valve (PRV) settings per tank which must be switched upon entering and exiting U.S. territorial waters.

 

5. DISCUSSION.
a. When references (b) and (c) were written, the stress factors were influenced by the requirements of reference (d) at the time. ASME has since lowered the stress factors.
b. According to 46 CFR 154.32, vessels may meet an alternative standard if the Commandant determines that the alternate standard provides an equivalent or greater level of safety. Materials, manufacturing, and inspection have advanced since the current regulations were written, and tanks designed and manufactured with these more advanced techniques and with the stress factors in the IGC Code have an equivalent level safety to the current regulations. Therefore tanks manufactured under certain conditions are considered to meet the level of safety required in 46 CFR 154.447 and 46 CFR 154.450.

 

6. PROCEDURES.
a. Tanks meeting the following two requirements may use MARVS specified in reference (a):
1. They must be designed and built according to the 1993 edition of the IGC code, including all amendments through 1 October 1994.
2. They must be on a vessel having an International Certificate of Fitness for the Carriage of Liquefied Gases in Bulk issued by a U.S. Coast Guard Recognized Classification Society authorized to issue such a certificate. (See 46 CFR part 8, subpart B). A current listing of U.S. Coast Guard Recognized Classification Societies is available at http://www.uscg.mil/hq/cg5/acp/.
b. Tanks that do not meet these requirements must meet current U.S. regulations. See references (b) and (c). Alternately, shipowners may request equivalencies to use the MARVS as determined from the IGC Code. Requests for equivalencies should be directed to the U.S. Coast Guard Commandant (CG-ENG-5) and must include the information required in 46 CFR 154.32(b) and should include a copy of the Certificate of Fitness.

 

7. DISCLAIMER. This policy 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.

8. QUESTIONS. Questions or concerns regarding this policy may be directed to Commandant (CG-ENG-5) at (202) 372-1412 or emailed to HazmatStandards@uscg.mil.

Maritime Reporter August 2014 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Tanker Trends

Ceremony Marks the Construction of 5 American Tankers

General Dynamics NASSCO and City of San Diego Mayor Kevin Faulconer today signaled the start of construction of five American Petroleum Tankers at a steel cutting ceremony for the first tanker,

Britain Loses Europe's Gas Trading Crown to the Dutch

Britain has been topped by the Netherlands as Europe's leading natural gas trading hub this summer, ending decades of British dominance in the sector. Britain

American Maritime Industry Booming Testifies AMP

The U.S. House Subcommittee on Coast Guard and Maritime Transportation today heard first hand about America’s booming domestic maritime industry from Mark Tabbutt,

Fuels & Lubes

Porter Voices Concerns Over Texas Pipelines

Commissioner David Porter of the Texas Railroad Commission (RRC) Tuesday visited several south Texas border oil and gas facilities and pipeline rights-of-way to meet with field staff,

DNV GL: Beyond Condition Monitoring in the Maritime Industry

Moving from a regime of scheduled rule-based maintenance to a data-driven risk-based regime can lead to more accurate and timely maintenance resulting in increased safety,

Brent Holds Above $98 Despite Weak Demand

Brent crude held above $98 a barrel on Friday, heading for its worst week in six as concerns over weak demand outweighed geopolitical worries in the Middle East and Ukraine.

Coast Guard

USCG Respond to Grounded Vessel near Pleasant Harbor, Washington

The Coast Guard and Washington State Department of Ecology are responding to a report a of 65-foot pleasure craft aground near Pleasant Harbor in Brinnon, Washington, Sunday morning.

USCG Confirm Jelly Fish Concentration in Buzzard's Bay, Massachusetts

Coast Guard pollution responders, and the Fairhaven Harbormaster responded to a report of a large oil sheen in Buzzards Bay, Massachusetts Friday morning. At 2:00 p.

USCG Repatriates Cuban Boat Migrants

The U.S. Coast Guard (USCG) Cutter Knight Island repatriated 45 Cuban migrants to Bahia de Cabañas, Cuba, Wednesday. These repatriations are a result of two

Maritime Safety

USCG Respond to Grounded Vessel near Pleasant Harbor, Washington

The Coast Guard and Washington State Department of Ecology are responding to a report a of 65-foot pleasure craft aground near Pleasant Harbor in Brinnon, Washington, Sunday morning.

General Dynamics Wins U.S. Navy Nuclear-Submarine Contract

The U.S. Navy has awarded a $234 million contract to General Dynamics Electric Boat to provide planning yard work, engineering and technical support for nuclear submarines.

Innovative KO-LINK Towing Ring from Lankhorst Ropes

The innovative KO-LINK towing ring, developed by international maritime service provider KOTUG International BV, is now available exclusively from leading maritime ropes supplier,

Government Update

Gazprom Scraps Plan to Cut Gas Deliveries

Russia's Gazprom scrapped a plan to cut gas exports to Romania by 9 percent on Saturday and by 5 percent on Sunday, Romania's Energy Minister Razvan Nicolescu said.

Pesticides a Concern for Aquatic Life in U.S. Rivers & Streams

Levels of pesticides continue to be a concern for aquatic life in many of the Nation’s rivers and streams in agricultural and urban areas, according to a new

Canada Invests in Harbor Grace Project

Senator Manning announces funding for a harbor improvement project Senator Fabian Manning, on behalf of the Honorable Gail Shea, Minister of Fisheries and Oceans,

 
 
Maritime Contracts Maritime Standards Naval Architecture Pipelines Pod Propulsion Ship Electronics Ship Simulators Shipbuilding / Vessel Construction Sonar Winch
rss | archive | history | articles | privacy | terms and conditions | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1683 sec (6 req/sec)