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

Tanker Trends

Imperial: Decision on Canadian LNG Project Distant

Imperial Oil Ltd said on Thursday it is not yet close to deciding on whether it will go ahead with a Canadian liquefied natural gas export plant it is exploring

Italian Pleads Guilty to Marine-hose Price-fixing in US

A former executive of Parker ITR Srl pleaded guilty on Thursday to conspiring to rig bids for marine hose and was sentenced to two years in prison, the U.S. Justice Department said on Thursday.

Knightsbridge, Frontline to Form US Capesize Company

Knightsbridge Tankers Limited and Frontline 2012 Ltd. have announced an agreement to combine Frontline 2012's remaining fleet of 25 fuel efficient vessels with Knightsbridge.

Fuels & Lubes

Knightsbridge, Frontline to Form US Capesize Company

Knightsbridge Tankers Limited and Frontline 2012 Ltd. have announced an agreement to combine Frontline 2012's remaining fleet of 25 fuel efficient vessels with Knightsbridge.

Marine Diesel Purification Breakthrough by SurePure

Liquid photopurification specialist company SurePure Inc. apprises of a breakthrough in the microbiological purification of contaminated marine diesel fuel, using

ABS Approves Design for GTTNA’s LNG Bunker Barge

GTT North America (GTTNA), the Houston-based subsidiary of French engineering and technology company Gaztransport & Technigaz SA (GTT), received approval in principle from ABS for the design of a 2,

Coast Guard

GAO: Limited Commercial Arctic Development Foreseen

Decreasing seasonal sea ice has opened up Arctic waters for longer periods with resulting potential economic opportunities in commercial shipping, cruises, commercial fishing, oil, and mining.

Canadian Icebreaker Refit Contracts Awarded

The Canadian Government informs it has awarded a $6.5 million contract to Babcock Canada Inc. for critical refit work for Canadian Coast Guard ship 'CCGS Louis S.

Resolve Maritime Academy to Host 'DC Olympics'

Resolve Maritime Academy informs it is to host the Damage Control (DC) Olympics as an annual event for officers and damage control crew of US Navy and US Coast

Maritime Safety

IMB: Piracy Falls to Lowest Level since 2007

The International Chamber of Commerce’s International Maritime Bureau (IMB) has revealed that piracy on the world’s seas is at its lowest first-quarter level since 2007,

Lawyer: Korea Ferry Owners Accept Responsibilities

The family that has a major stake in companies that control the shipping operator whose ferry sank last week, likely to have killed hundreds, will take social and

Korean Ferry: Pair Drowned with PFD's Tied Together

A boy and girl trapped in a sinking South Korean ferry with hundreds of other high school students tied their life jacket cords together, a diver who recovered their bodies said,

Government Update

Offshore O&G: Cuts, Delays in Norway as Costs Soar

More oil and gas projects in Norway could be put on hold because of rising costs, adding to a growing list of developments that have been delayed or called off,

Court: Japan's Mitsui Paid to Release Ship

China Supreme Court says Mitsui pays about $29 mln; Ship released about 0030 GMT Thursday. Ship was seized over dispute dating back to 1930s. Advisor to plaintiffs says will likely demand more money.

Korean Ferry: Pair Drowned with PFD's Tied Together

A boy and girl trapped in a sinking South Korean ferry with hundreds of other high school students tied their life jacket cords together, a diver who recovered their bodies said,

 
 
Maritime Careers / Shipboard Positions Maritime Standards Naval Architecture Offshore Oil Pipelines Pod Propulsion Port Authority Ship Repair Ship Simulators Shipbuilding / Vessel Construction
rss | archive | history | articles | privacy | 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: 0.1352 sec (7 req/sec)