Post on 14-Apr-2018
transcript
7/29/2019 Gas Cargoes
1/56
LPG / LNG
A liquefied gas is the liquid form of a substancewhich at normal ambient temperatures &atmospheric pressure, would be a gas.
LPGthe generic term for propane, butane &
mixtures of the two.
LPG obtained from
Crude oil processing in refineries
Chemical plant by-products
LNG obtained from
Natural gas streams
Large oil fields
7/29/2019 Gas Cargoes
2/56
Ship Types
LPG / Chlorine
Fully pressurisedSpherical tanks
Cylindrical tanks
7/29/2019 Gas Cargoes
3/56
Ship Types
LPG / LEG / Chemical gases
Semi-pressurised ships
Spherical tanks
Cylindrical tanks
Lobe tanks
7/29/2019 Gas Cargoes
4/56
Ship Types
LPG / LEG / LNG
Fully refrigerated ships
Spherical tanks
Membrane tanks
Semi-membrane tanks
Independent tanks
Integral tanks
7/29/2019 Gas Cargoes
5/56
Semi-Refrigerated LPG
7/29/2019 Gas Cargoes
6/56
Semi-Refrigerated LPG
7/29/2019 Gas Cargoes
7/56
Semi-Refrigerated LPG
7/29/2019 Gas Cargoes
8/56
Fully Refrigerated LPG
7/29/2019 Gas Cargoes
9/56
Fully Refrigerated LNG
7/29/2019 Gas Cargoes
10/56
Fully Refrigerated LNG
7/29/2019 Gas Cargoes
11/56
Fully Refrigerated LNG
7/29/2019 Gas Cargoes
12/56
Fully Refrigerated LNG
7/29/2019 Gas Cargoes
13/56
Fully Refrigerated LNG
7/29/2019 Gas Cargoes
14/56
Membrane Tank
7/29/2019 Gas Cargoes
15/56
The Gas Carrier Codes
7/29/2019 Gas Cargoes
16/56
The Gas Carrier Codes
The I nternational Code for the Construction
& Equipment of Ships Carrying Liquef ied
Gases in BulkIGC Code
Ships built after June 1986
Made mandatory by SOLAS Ch.VI I
International Certificate of Fitness
7/29/2019 Gas Cargoes
17/56
The Gas Carrier Codes
The Code for the Construction & Equipmentof Ships Carrying L iquef ied Gases in Bulk
Gas Carrier (GC) Code
Ships built between 1976 & 1986 NOT mandatory
Implemented into national law by many
countries Charterers would expect compliance
Certificate of Fitness
7/29/2019 Gas Cargoes
18/56
The Gas Carrier Codes
The I nternational Code for Existing Ships
Carrying Liquef ied Gases in Bulk
Existing Ship Code
Ships built before 1977
Completed in 1976 after GC Code written
IMO recommendation for older ships
Charterers / terminal expect compliance
Certificate of Fitness
7/29/2019 Gas Cargoes
19/56
IGC Code - Ship Types
Type 1G
Designed with maximum preventative measures
Type 2G Designed with significant preventative measures
Type 2PG
As above but LOA < 150m, tanks designed for > 7 bar
pressure and above
550
Type 3G
Designed with moderate preventative measures
7/29/2019 Gas Cargoes
20/56
Ship Arrangements
Gas-Dangerous Spaces
Spaces where gas-safe conditions are not assured
Enclosed spaces outside cargo area containing
cargo piping
Cargo containment systems and piping
Hold spaces
Pump rooms & compressor rooms
7/29/2019 Gas Cargoes
21/56
Ship ArrangementsGas-Dangerous Zones
Zone on the open deck within 3m of: -
Cargo tank outlet
Vapour outlet
Cargo pipe flange
Cargo pipe valve
Entrances or vents to pump or compressor rooms
7/29/2019 Gas Cargoes
22/56
Ship ArrangementsGas-Dangerous Zones
Open deck over cargo areas
3m fwd & aft of cargo areas on open deck
2.4m above weather deck
Within 2.4m of exposed cargo containment system
Spaces containing cargo pipes
Enclosed/semi-enclosed space opening into a gas
dangerous space or zone
7/29/2019 Gas Cargoes
23/56
7/29/2019 Gas Cargoes
24/56
7/29/2019 Gas Cargoes
25/56
7/29/2019 Gas Cargoes
26/56
INERTING
7/29/2019 Gas Cargoes
27/56
INERTING
GASSING UP li id f h
7/29/2019 Gas Cargoes
28/56
GASSING UP - liquid from shore
GASSING UP f h
7/29/2019 Gas Cargoes
29/56
GASSING UP - vapour from shore
COOLDOWN li id f h
7/29/2019 Gas Cargoes
30/56
COOLDOWN - liquid from shore
LOADING ith t li
7/29/2019 Gas Cargoes
31/56
LOADING - with vapour return line
LOADING ith t t li
7/29/2019 Gas Cargoes
32/56
LOADING - without vapour return line
LOADED PASSAGE li
7/29/2019 Gas Cargoes
33/56
LOADED PASSAGE - cooling
LOADED PASSAGE diti i
7/29/2019 Gas Cargoes
34/56
LOADED PASSAGE - conditioning
DISCHARGING i h li
7/29/2019 Gas Cargoes
35/56
DISCHARGING - without vapour return line
DISCHARGING ith t li
7/29/2019 Gas Cargoes
36/56
DISCHARGING - with vapour return line
LIQUID FREEING
7/29/2019 Gas Cargoes
37/56
LIQUID FREEING
BALLAST PASSAGE
7/29/2019 Gas Cargoes
38/56
BALLAST PASSAGE
PURGING vapour from shore
7/29/2019 Gas Cargoes
39/56
PURGING - vapour from shore
New cargo
vapour
Old cargo
vapour
INERTING to displace cargo apo rs
7/29/2019 Gas Cargoes
40/56
INERTING - to displace cargo vapours
AERATION gas freeing
7/29/2019 Gas Cargoes
41/56
AERATION - gas freeing
7/29/2019 Gas Cargoes
42/56
HEALTH HAZARDS
TOXICITY
ANAESTHESIA
ASPHYXIA
FROSTBITE
7/29/2019 Gas Cargoes
43/56
Health Hazards of Specific Cargoes
Ammonia TLV 25 ppm
Effects of L iquid Effects of Vapour
On Eyes Permanent damage
Frostbite
Irritationburning
Frostbite
On Skin Severe chemical burnsFrostbite
IrritationburningFrostbite
Skin Absorption Not absorbed
I ngestion Very harmful
Inhalation Convulsive coughing
Lung damage
Heart failure & cessation of
breathing
7/29/2019 Gas Cargoes
44/56
Butadiene TLV 10 ppm
Effects of L iquid Effects of Vapour
On Eyes Moderate irritation
Can cause damage
Moderate irritation
On Skin Moderate irritation
Superficial frostbite if
contact prolonged
May cause frostbite
Skin Absorption No hazard
I ngestion No known hazard
Inhalation Respiratory tract irritationHeadache, dizziness,
anaesthesia
Impairs central nervous system
Liver disorder
Carcinogenic
7/29/2019 Gas Cargoes
45/56
Chlorine TLV 0.5 ppm
Effects of L iquid Effects of Vapour
On Eyes Severe chemical & coldburns in small amounts
Severe irritation & burning
On Skin Severe chemical & coldburns even through normal
clothing
Severe irritation & burning
Skin Absorption Toxic & corrosive acidsformed with skin moisture
I ngestion Not pertinent
Inhalation Coughing, choking, sneezing,copious salivation, excitement
Bronchitis, teeth erosion,
inflammation of mucuous
membranes
7/29/2019 Gas Cargoes
46/56
Sulphur Dioxide TLV 2 ppm
Effects of L iquid Effects of Vapour
On Eyes Severe burns
Frostbite
Irritation & inflammation
On Skin Severe burns to moist areas
Frostbite
Irritation of moist skin in high
concentrations
Skin Absorption Not absorbed
I ngestion Severe internal burning
Inhalation Burning of respiratory tract
Severe choking
Oedema
Dizziness
Fatal respiratory paralysis
7/29/2019 Gas Cargoes
47/56
First-Aid Treatment
Cargo Data Sheets Medical First Aid Guide
First-Aid Equipment IGC CodeChapter 14
stretcher
resuscitation equipment
antidotes
CARGO DATA SHEETS
7/29/2019 Gas Cargoes
48/56
CARGO DATA SHEETSEmergency (first-aid) Procedures
AMMONIA PROCEDURES
L iquid in Eye DO NOT DELAY
Flood with fresh water or solution of distilled water & 2.5%
borax and 2.5% boric acid
Continue flooding for at least 30 minutes
Obtain medical assistance as soon as possible
L iquid on Skin DO NOT DELAY
Remove clothing & flood area with water for at least 15
minutes. Apply wet compress of distilled water & 2.5%
borax and 2.5% boric acid. Do not rub. Immerse frost-bitten
area in warm water until thawed. Obtain medical assistanceas soon as possible.
Vapour I nhaled REMOVE VICTIM TO FRESH AIR
Remove clothing. Mouth warm and still. Obtain medical
assistance as soon as possible.
7/29/2019 Gas Cargoes
49/56
REACTIVITY
Cargo may react with:- Water
Air Itself
Other cargoes
Other materials
7/29/2019 Gas Cargoes
50/56
REACTIVITY
Reactions may result in:- Toxic vapour emission
Heat generation Explosion
Corrosion
7/29/2019 Gas Cargoes
51/56
REACTION WITH WATER
Hydrate Formation HYDRATE
crushed ice or slush-like substance
May be caused by:- high dew point of purge vapours
water in cargo system prior to loading
water dissolved in the cargo (some LPGs) May cause seizure of pumps & equipment failure
7/29/2019 Gas Cargoes
52/56
REACTION WITH AIR
Formation of unstable oxygencompounds
May cause explosion Inert gas blankets
Shippers inhibitor added
7/29/2019 Gas Cargoes
53/56
SELF-REACTION
Polymerisation Initiated by small quantities of other cargoes
Catalyst may be presence of certain metals
Heat produced which accelerates reaction
Butadiene
Isoprene
Vinyl chloride monomer (VCM)
Some cargoes cannot be inhibited Ethylene oxide
Propylene oxide
7/29/2019 Gas Cargoes
54/56
REACTION WITH OTHER CARGOES
Separate piping system
Separate ventilation system
Separate refrigeration system Compatibility charts consulted
Cargo data sheets consulted
Effective purging prior to change of cargo
7/29/2019 Gas Cargoes
55/56
REACTION WITH OTHER MATERIALS
Materials in cargo system
Poor quality purge vapours
Consult cargo data sheets Effective stowage plan
High quality IG (CO2 content)
Prevent contamination with machinery oil
7/29/2019 Gas Cargoes
56/56
CORROSIVITY
Some cargoes & inhibitors may be corrosive
Cargo systems & human tissue at risk
Cargo system materials as per IMO Codes Refer to cargo data sheets