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 July 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Tanker Trends

Tanker Retrofitted with Dual Fuel Engine

Caterpillar Marine informs it has begin a dual fuel engine retrofit conversion onboard the 472-foot Fure West tanker, owned by Furetank Rederi A/B. The MaK M 43

GasLog Orders Two LNG Carriers

GasLog Ltd. today announced that it has ordered two new 174,000 cubic meter LNG carriers from Hyundai Heavy Industries Co., Ltd. ("Hyundai") in South Korea.

Ondimar Firms Order Suezmax Quartet at Navantia

Navantia and Maritime Transport Ondimar LDA (shipping company Ibaizabal Group) today ratified the contracts signed in late June and the financial structure for

Fuels & Lubes

Tanker Retrofitted with Dual Fuel Engine

Caterpillar Marine informs it has begin a dual fuel engine retrofit conversion onboard the 472-foot Fure West tanker, owned by Furetank Rederi A/B. The MaK M 43

Thordon Bearings Secures AK Ferry Contract

Thordon Bearings has received an order to supply its COMPAC system to two Alaska Ferry newbuilds under construction at the Vigor Industrial shipyard in Ketchikan, Alaska.

West Africa's August Crude Exports to Asia to Slip

West African crude oil exports to Asia were expected to fall to 1.84 million barrels per day (bpd) in August, Reuters data and a survey of traders showed.     Slower

Coast Guard

ASEAN: China Shuns South China Sea Dialogue

Chinese Vice Foreign Minister Liu Zhenmin said on Monday the disputed South China Sea should not be discussed at a meeting of the Association of Southeast Asian Nations (ASEAN).

Injured Woman Rescued on Lake Washington

Coast Guard, Seattle Police Department, Seattle Fire Department, King County Sheriff’s Office and Washington Department of Fish and Wildlife personnel rescued

Boxships Collide in Port Klang, Malaysia

The container ships MOL Empire and Northern Democrat collided at around 1430 LT Aug 1 in Westport harbor at Port Klang, Malaysia, reportedly while mooring.   Container or containers fell overboard,

Maritime Safety

TSB Investigating Ferry, Pleasure Craft Collision

The Transportation Safety Board of Canada (TSB) is deploying a team of investigators to Laval, Quebec, following a collision between the ferry Paule II and a pleasure craft which occurred on August 1.

First Vessel of New Rescue Class Launched

Global shipping and energy services firm, Craig Group, has launched its first F-Class vessel, the Grampian Fortress. The IMT 958 multi-role emergency response and

MacArthur Lock Dewatered for Emergency Repairs

The U.S. Army Corps of Engineers, Detroit District, announced the MacArthur Lock, located on the Soo Locks at Sault Ste. Marie, Mich., is experiencing mechanical

Government Update

ASEAN: China Shuns South China Sea Dialogue

Chinese Vice Foreign Minister Liu Zhenmin said on Monday the disputed South China Sea should not be discussed at a meeting of the Association of Southeast Asian Nations (ASEAN).

Contship Italia Signs Iran MoU

Contship Italia Spa, also on behalf of Eurogate GmbH & Co. KGaA, KG, recently signed a strategic Memorandum of Understanding (M.O.U.) with Sina Port & Marine Company (SPMCO),

Boxships Collide in Port Klang, Malaysia

The container ships MOL Empire and Northern Democrat collided at around 1430 LT Aug 1 in Westport harbor at Port Klang, Malaysia, reportedly while mooring.   Container or containers fell overboard,

 
 
Maritime Security Maritime Standards Naval Architecture Navigation Pipelines Pod Propulsion Salvage Ship Simulators Shipbuilding / Vessel Construction Sonar
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: 0.1507 sec (7 req/sec)