1 Lesson Topic 3.1 Lesson Topic 3.1 CLEANING AND GAS CLEANING AND GAS FREEING FREEING
Dec 26, 2015
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INTRODUCTIONINTRODUCTION
As Gas Free Engineering As Gas Free Engineering Personnel you will be expected to Personnel you will be expected to know the various methods know the various methods available to clean tanks and available to clean tanks and requirements to make them gas requirements to make them gas freefree..
Lesson Topic 3.1, Cleaning and Gas Freeing
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ENABLING OBJECTIVESENABLING OBJECTIVES
Describe the procedures, equipment and Describe the procedures, equipment and personnel safety precautions used with personnel safety precautions used with the Butterworthing method, Chemical the Butterworthing method, Chemical cleaning, Steam Cleaning, and Hot or cleaning, Steam Cleaning, and Hot or Cold washing in accordance with NSTM Cold washing in accordance with NSTM Chapter 074 Vol. 3, Gas Free Engineering, Chapter 074 Vol. 3, Gas Free Engineering, NSTM Chapter 631 Vol. 2, Preservation of NSTM Chapter 631 Vol. 2, Preservation of Ships in Service - Surface Preparation and Ships in Service - Surface Preparation and Painting, Manual for Cargo Tank Cleaning Painting, Manual for Cargo Tank Cleaning and OPNAVINST 5100.19, series.and OPNAVINST 5100.19, series.
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ENABLING OBJECTIVESENABLING OBJECTIVES
Describe the cleaning process, testing, Describe the cleaning process, testing, safety precautions and procedures safety precautions and procedures required for entry into DFM/F-76, CHT, required for entry into DFM/F-76, CHT, JP-5, and Gasoline tanks, in accordance JP-5, and Gasoline tanks, in accordance with NSTM Chapter 074 Vol. 3, Gas Free with NSTM Chapter 074 Vol. 3, Gas Free Engineering, NSTM Chapter 631 Vol. 2, Engineering, NSTM Chapter 631 Vol. 2, Preservation of Ships in Service - Surface Preservation of Ships in Service - Surface Preparation and Painting, NSTM Chapter Preparation and Painting, NSTM Chapter 541, Ship Fuel and Fuel Systems and 541, Ship Fuel and Fuel Systems and OPNAVINST 5100.19, series.OPNAVINST 5100.19, series.
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Tank Cleaning RequirementsTank Cleaning Requirements
• Maintenance cleaningMaintenance cleaning• Tank inspection or minor repairTank inspection or minor repair• Shipyard overhaul or major repairShipyard overhaul or major repair• Change of cargoChange of cargo• After a contaminated cargoAfter a contaminated cargo• Preparation for loadingPreparation for loading• Preparation for ballastingPreparation for ballasting• Activation and inactivation of vesselActivation and inactivation of vessel
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Tank CleaningTank Cleaning
Spaces like fuel tanks are normally Spaces like fuel tanks are normally cleaned in a properly equipped shore cleaned in a properly equipped shore support facility.support facility.• Only properly equipped ships like oilers Only properly equipped ships like oilers
will clean such spaces as a matter of will clean such spaces as a matter of normal routine.normal routine.
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Tank CleaningTank Cleaning
• Initial testing and evaluation of the space. Initial testing and evaluation of the space. • Prescribing conditions of entry for Prescribing conditions of entry for
cleaning.cleaning.
Gas Free Engineer responsibilities
NOTE: The GFE will know the various cleaning
methods for any given circumstance, in order to
evaluate any hazard that may develop during or
after cleaning.
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Tank CleaningTank Cleaning
• Issuance of a provisional certificate Issuance of a provisional certificate • Specifying conditions during cleaningSpecifying conditions during cleaning• Testing and evaluation of the space after Testing and evaluation of the space after
cleaning.cleaning.• Collaboration, when necessary, with Collaboration, when necessary, with
cleaning personnel.cleaning personnel.
Gas Free Engineer responsibilitiesGas Free Engineer responsibilities
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Tank CleaningTank Cleaning
• Inspecting personnelInspecting personnel
Precautions prior to tank cleaning
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Tank CleaningTank Cleaning
• Inspecting personnelInspecting personnel– Proper clothingProper clothing– Proper equipmentProper equipment
Precautions prior to tank cleaning
NOTE: The safety observer should have a list of
the equipment to be allowed into the space.
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Tank CleaningTank Cleaning
• Inspecting personnelInspecting personnel– Proper clothingProper clothing– Proper equipmentProper equipment
– Not intoxicated or on drugsNot intoxicated or on drugs
Precautions prior to tank cleaning
NOTE: The safety observer should have a list of
the equipment to be allowed into the space.
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Tank CleaningTank Cleaning
• Common hazardsCommon hazards– Use caution when entering or leaving tanks to Use caution when entering or leaving tanks to
avoid are slipping or falling, low overheads, avoid are slipping or falling, low overheads, and electrical shock.and electrical shock.
• Physical hazards can be avoided byPhysical hazards can be avoided by– Proper instruction of personnelProper instruction of personnel– Good judgementGood judgement– Constant alertnessConstant alertness
Precautions prior to tank cleaning
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Tank CleaningTank Cleaning
• Tending linesTending lines– Prevent lines and hoses from becoming Prevent lines and hoses from becoming
tangled.tangled.– Do not pull on hosesDo not pull on hoses– Do not climb on pipesDo not climb on pipes
Safety equipment
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Tank CleaningTank Cleaning
• Provide sufficient lightingProvide sufficient lighting– Explosive proofExplosive proof– Cables should be tied upCables should be tied up– ScaffoldingScaffolding– Ladders with non-skid tipsLadders with non-skid tips– Safety nets, beltsSafety nets, belts
Safety equipment
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Tank CleaningTank Cleaning
• Ensure that NO:Ensure that NO:– STEAM is admitted to tank with personnel STEAM is admitted to tank with personnel
insideinside– HIGH PRESSURE WATER is directed through HIGH PRESSURE WATER is directed through
manhole with personnel inside.manhole with personnel inside.
Safety precautions
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Tank CleaningTank Cleaning
•Always be aware of potential Always be aware of potential danger due to the extremely danger due to the extremely hazardous situation inside a dark hazardous situation inside a dark fuel tank.fuel tank.
Safety precautions
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Tank Cleaning ApplicationsTank Cleaning Applications
Many effective cleaning methods may be Many effective cleaning methods may be used to used to
clean a confined or enclosed space.clean a confined or enclosed space.
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Tank Cleaning ApplicationsTank Cleaning Applications
Selection of method may be governed Selection of method may be governed by:by:• Materials availableMaterials available• The product involved (cleaning agent)The product involved (cleaning agent)• Time allottedTime allotted• Tank conditionTank condition
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Tank Cleaning ApplicationsTank Cleaning Applications
• Effective when used in conjunction with Effective when used in conjunction with the Wheeler method.the Wheeler method.
• Suitable method of employing chemicals Suitable method of employing chemicals will be governed by:will be governed by:– Type of cleaningType of cleaning– Equipment availableEquipment available– Time allottedTime allotted
Chemical cleaning
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Tank Cleaning ApplicationsTank Cleaning Applications
• Regardless of the method, all personnel Regardless of the method, all personnel shall be thoroughly indoctrinated in safe shall be thoroughly indoctrinated in safe handling of:handling of:– Chemical solventsChemical solvents– EmulsifiersEmulsifiers
Chemical cleaning
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Tank Cleaning ApplicationsTank Cleaning Applications
Butterworthing
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Tank Cleaning ApplicationsTank Cleaning Applications
• Requires heated water (or cleaning oil)Requires heated water (or cleaning oil)– High pressure (175 PSI)High pressure (175 PSI)– Revolving nozzleRevolving nozzle– Water temperature 165-185°FWater temperature 165-185°F
ButterworthingButterworthing
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Tank Cleaning ApplicationsTank Cleaning Applications
• Nozzle raised and loweredNozzle raised and lowered
ButterworthingButterworthing
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Tank Cleaning ApplicationsTank Cleaning Applications
• Tank stripped continuously until the Tank stripped continuously until the bottom is free of water, with the nozzle bottom is free of water, with the nozzle stream stirring sediment.stream stirring sediment.
ButterworthingButterworthing
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Tank Cleaning ApplicationsTank Cleaning Applications
• Water is supplied through specially Water is supplied through specially constructed ground hose.constructed ground hose.
ButterworthingButterworthing
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Tank Cleaning ApplicationsTank Cleaning Applications
• Most thorough method of cleaning tanks.
• Consists of melting down materials
• No set procedure can be established to suit all fuel tanks
Steam cleaningSteam cleaning
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Tank Cleaning ApplicationsTank Cleaning Applications
• Temperature of tank walls during steam Temperature of tank walls during steam cleaning must not be allowed to exceed cleaning must not be allowed to exceed 230°F230°F..CAUTION: Excessive temperature may cause
buckling of walls, warping or cracking of
structures, and may also dangerously overheat
flammable or combustible materials within
boundary spaces..
Steam cleaningSteam cleaning
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Tank Cleaning ApplicationsTank Cleaning Applications
• Caution must be used when attempting to Caution must be used when attempting to steam clean tanks.steam clean tanks.
• Tanks containing gasoline must be steam Tanks containing gasoline must be steam cleanedcleaned..
Steam cleaningSteam cleaning
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Tank Cleaning ApplicationsTank Cleaning Applications
• Method of cleaning using water under Method of cleaning using water under pressure pressure
• In most instances, tanks containing In most instances, tanks containing hydrocarbons must be thoroughly hydrocarbons must be thoroughly steamed or treated with cleaning steamed or treated with cleaning compounds before being washed.compounds before being washed.
Water washingWater washing
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Method of Gas Freeing Method of Gas Freeing DFM / F-76 / JP-5 Tanks DFM / F-76 / JP-5 Tanks
and CHT systemsand CHT systems
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Gas Freeing DFM / F-76 / JP-5 Tanks Gas Freeing DFM / F-76 / JP-5 Tanks and CHT systemsand CHT systems
Written permission from the Written permission from the Commanding Officer is required to Commanding Officer is required to open tanks.open tanks.
Remove manhole cover.Remove manhole cover.• If presence of hydrocarbon vapors is If presence of hydrocarbon vapors is
suspected, suspected,
use non-sparking tools.use non-sparking tools.
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Gas Freeing DFM / F-76 / JP-5 Gas Freeing DFM / F-76 / JP-5 Tanks and CHT systemsTanks and CHT systems
Test for oxygen deficiencyTest for oxygen deficiency• Do not enter tankDo not enter tank• Use drop check methodUse drop check method
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Gas Freeing DFM / F-76 / JP-5 Gas Freeing DFM / F-76 / JP-5 Tanks and CHT systemsTanks and CHT systems
Test for combustible vaporsTest for combustible vapors• Do not enter tankDo not enter tank• Use drop check methodUse drop check method
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Gas Freeing DFM / F-76 / JP-5 Gas Freeing DFM / F-76 / JP-5 Tanks and CHT systemsTanks and CHT systems
Test for toxic conditionsTest for toxic conditions• Do not enter tankDo not enter tank• Use drop check methodUse drop check method
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• Testing tank every eight hours or as Testing tank every eight hours or as necessarynecessary
• Inspecting tanks for cleanlinessInspecting tanks for cleanliness• Ensuring safe atmospheric conditions existEnsuring safe atmospheric conditions exist• Certifying tank: Safe for Personnel Safe Certifying tank: Safe for Personnel Safe
for Hot Workfor Hot Work
Gas free engineer is Gas free engineer is responsible for:responsible for:
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Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
• A heavy blanket of organic sludge can A heavy blanket of organic sludge can accumulate on the bottom of a tank during accumulate on the bottom of a tank during routine CHT operations.routine CHT operations.
• The underlying layer of sludge generates The underlying layer of sludge generates hazardous gases -- hydrogen sulfide and hazardous gases -- hydrogen sulfide and methanemethane
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• Potential hazards exist when personnel Potential hazards exist when personnel are working on, or in, an open tank.are working on, or in, an open tank.
• Enforce safety precautions to ensure that Enforce safety precautions to ensure that health and well being of personnel are health and well being of personnel are protected.protected.
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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• CHT tank inspection and maintenance CHT tank inspection and maintenance requiring tank entry.requiring tank entry.
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
Lesson Topic 3.1, Cleaning and Gas Freeing
NOTE:All procedures for preparing a CHT tank for cleaning
must be followed and adhered i.a.w. written procedures
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• Safety precautions for personnel prior to Safety precautions for personnel prior to tank opening:tank opening:– Wear approved respiratory equipmentWear approved respiratory equipment
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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• Safety precautions for personnel prior to Safety precautions for personnel prior to tank opening:tank opening:– Two people will be outside the tank to:Two people will be outside the tank to:
– Constantly observe personnel insideConstantly observe personnel inside– Render assistance if requiredRender assistance if required– Provide spare respiratory equipment for Provide spare respiratory equipment for
immediate useimmediate use
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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• After opening tankAfter opening tank– Test the atmosphere of the spaceTest the atmosphere of the space
– O²O²– ExplosiveExplosive– ToxicsToxics
– If the tank is not gas free, repeat the If the tank is not gas free, repeat the washdown procedures; retest and washdown procedures; retest and certify gas free if safe.certify gas free if safe.
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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– Recertification is made periodically: Recertification is made periodically: – No more than every eight hoursNo more than every eight hours and each and each
time the ship moves or as specified by the time the ship moves or as specified by the GFE.GFE.
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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• VentilationVentilation– Force ventilate continuously Force ventilate continuously
taking suction from bottom oftaking suction from bottom of
tank and discharging directly tank and discharging directly
to weather deck.to weather deck.– Make one complete air change Make one complete air change
every three minutes.every three minutes.
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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• Before tank entryBefore tank entry– Force ventilate for 30 minutes.Force ventilate for 30 minutes.– Clean thoroughly without enteringClean thoroughly without entering– Continue ventilation during washdownContinue ventilation during washdown– Gas Free Engineer tests tank.Gas Free Engineer tests tank.– If conditions are unsafe, continue ventilation If conditions are unsafe, continue ventilation
and washdown until certified and safe.and washdown until certified and safe.
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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• Equipment and clothing worn by Equipment and clothing worn by personnel for tank entry.personnel for tank entry.– Respiratory protectionRespiratory protection– Coveralls (white CHT)Coveralls (white CHT)– BootsBoots– GlovesGloves– Head coveringHead covering
Sewage Collection, Holding, and Sewage Collection, Holding, and Transfer SystemsTransfer Systems
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• Protective equipment required for tank Protective equipment required for tank entry:entry:– Respiratory equipmentRespiratory equipment– Protective clothing (light-colored Protective clothing (light-colored
material coverall )material coverall )– Acid-resistant bootsAcid-resistant boots– Acid-resistant glovesAcid-resistant gloves
Gasoline TanksGasoline Tanks
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• All spaces into which gasoline vapors issue All spaces into which gasoline vapors issue must be constantly and thoroughly must be constantly and thoroughly ventilated.ventilated.
WARNING: BREATHING AIR RICH IN
GASOLINE VAPORS CAN CAUSE DEATH.
Gasoline TanksGasoline Tanks
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• No person shall enter a gasoline No person shall enter a gasoline storage tank for any purpose without storage tank for any purpose without obtaining the Commanding Officer's obtaining the Commanding Officer's permission each time.permission each time.
Gasoline TanksGasoline Tanks
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• Procedures for entering a tank certified Procedures for entering a tank certified gas free and safegas free and safe– Enter the tank and remove remaining sludgeEnter the tank and remove remaining sludge
NOTE: If only one person enters a tank, a safety
harness and tending line must be used.
Gasoline TanksGasoline Tanks
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• After sludge removal and tank cleaningAfter sludge removal and tank cleaning– Retest and certify gas free and safe, or Retest and certify gas free and safe, or
unsafe.unsafe.– If unsafe then ventilate and repeat If unsafe then ventilate and repeat
washdown procedures until certified gas washdown procedures until certified gas free and safe.free and safe.
Gasoline TanksGasoline Tanks
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• If safe, Work can now continue inside If safe, Work can now continue inside the tank without respiratory equipment the tank without respiratory equipment with:with:– Continuous ventilation Continuous ventilation – GFE approvalGFE approval
Gasoline TanksGasoline Tanks
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• The frequency of testing to be performed The frequency of testing to be performed is stated on the gas free certificate.is stated on the gas free certificate.
WARNING: No welding or hot work shall be
performed on the tank until the Gas Free Engineer
certifies the tank is safe for hot work.
Gasoline TanksGasoline Tanks
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Review and SummaryReview and Summary
Tank CleaningTank Cleaning Tank Cleaning ApplicationsTank Cleaning Applications Method of Gas Freeing DFM / F-76 / JP-Method of Gas Freeing DFM / F-76 / JP-
5 Tanks and CHT systems5 Tanks and CHT systems
Lesson Topic 3.1, Cleaning and Gas Freeing