TANK CLEANING INERTING

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TANK CLEANING INERTING AND PRESSING-UP
7.16
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ENABLING OBJECTS
DESCRIBE the following methods of tank
cleaning   a) Hot or Cold Water Wash b)
Steam Cleaning c) Butterworthing /
Wheelerizing d) Chemical Cleaning e)
Biological Cleaning   DESCRIBE the
proper cleaning and testing processes for safe
entry and hot work in the following
types of tanks   a) Diesel Fuel Marine
(DFM) b) JP-5 c) Gasoline d) Collection,
Holding and Transfer (CHT) e) Closed
Compartments   DESCRIBE the safety
precautions and procedures for performing
emergency hot work on tanks when
proper cleaning cannot be accomplished and the
following methods are used 
a) Inerting b) Pressing-Up c) Steam
Blanketing
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REFERENCES
-MILITARY HDBK,CARGO TANK CLEANING NAVSEA
MIL-HDBK-291
-GAS FREE ENGINEERING, NSTM 074, VOLUME 3 (sect
23 24)
-PETROLEUM FUEL STOWAGE, NSTM 541
-GASOLINE AND JP-5 SYSTEMS, NSTM 542
-POLLUTION CONTROL, NSTM 593
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REASONS TO CLEAN
-SCHEDULED MAINTENANCE - INTERVAL DETERMINED BY
PMS BASED ON SYSTEM TYPE AND NATURE OF CARGO
CARRIED
-CORRECTIVE MAINTENANCE- EX REPAIR TANK LEVEL
INDICATORS CLEARING FOULED SOUNDING TUBES
-AFTER BALLASTING -AFTER REMOVING CONTAMINATED
CARGO
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Safety precautions during cleaning
operations   1. Ensure tank atmosphere is
routed to the weather decks.   (a) Seal off
other spaces-set Zebra-establish fume tight
boundary. (b) Use 8/10
non-collapsible ducting to route atmosphere to
weather decks.   2. Smoking
lamp out except for designated spaces   3. 200'
exclusion area around tank.   4. No open flame,
hot work, operating engines, exposed lights.
5. Tank cleaning personnel may NOT have
cigarette lighters, matches, exposed lights
(flashlights).   6. All metal on tank cleaning
personnel must be removed, i.e., rings, watches,
belt buckles, key chains, etc.   7. Supplied
Air device is required unless not carried on
board.   8. Tank continuously vented - gas
freed.  
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9. Safety observer at tank access opening.  
Keep count of of men in tank.
Keep in contact with men in tank. Sound
the alarm if necessary. 10. Suitable fire
extinguishing apparatus available. 11. Use only
non sparking tools. 12. All clothing worn must be
changed and washed at the
end of each
day. 13. Utilize proper protective clothing and
footwear. Water or oil coated surfaces are
slick. Wear rubber soled boots.
Molded hand wear and no loose clothing.
Goggles and respirator. 14. Use
lifelines. 15. Designate and man Rescue Control
Point  
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CLEANING METHODS
WATER WASH
CHEMICAL
BUTTERWORTHING
STEAM
BIOLOGICAL
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WATER WASH
-MOST COMMON TYPE OF CLEANING
-MUST PROVIDE A CONTINUOUS DEWATERING (MUCKING)
-BUDDY SYSTEM
-WIPE DOWN WITH RAGS
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CHEMICAL
-FOR TOUGH TO CLEAN JOBS
-HANDLING AND HAZARDOUS WASTE PROBLEM -THOROUGH
FINAL RINSE REQUIRED TO PREVENT CONTAMINATION OF
THE PRODUCT
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BUTTERWORTHING
-MECHANICAL METHOD
-PROCESS NAME IS DERIVED FROM EQUIPMENT NAME
-HOT WATER AT HIGH PRESSURE (175 PSI) DIRECTED
360 DEG THROUGH 1/2 NOZZLES AT A RATE OF 180
GPM - FOR TANKS WITH EPOXY COATING WATER TEMP IS
LIMITED TO 1250F
-TANK MUST BE CONTINUALLY STRIPPED
-NORMALLY ACCOMPLISHED AT SHIPYARDS AND ABOARD
AO'S,AOR'S AND AOE'S
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(No Transcript)
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(No Transcript)
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STEAM CLEANING
-CANNOT BE USED ON PLASTIC OR EPOXY COATED TANKS
(JP-5)
-USED TO STEAM OUT MOGAS TANKS
-TEMP MAY NOT EXCEED 2300F.
-APPLY 50 OR 150 PSI STEAM FOR A PERIOD OF 24
HOURS THROUGH TANK TOP CONNECTION
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BIOLOGICAL
-USED FOR CHT AND FUEL TANKS
-USE IN COLD WATER
-FLUSH TANK AND FILL WITH FRESH WATER USE
GLOVES, COVERALLS AND SUPPLIED AIR DEVICE WHILE
HANDLING MICROBES
-LET STAND FOR 48 HOURS THEN DUMP AND FLUSH
-CHLORINATE X 4 HOURS TO SANITIZE TANK
-HAZARDOUS MATERIAL?
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DFM/JP-5 TANKS
-IDLH SPACE
-WATER WASH
-WASH FROM TOP DOWN
-REMOVE SLUDGE CONTINUOUSLY
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APPLICATION OF CLEANING METHODS

• OBTAIN CO PERMISSION TO ENTER IDLH SPACE
• OPEN TANK, CONDUCT DROP TEST AND VENTILATE PER
  NSTM 074
• CONDUCT DROP TEST, GFE ENTER TANK USING SUPPLIED
  AIR BREATHING APPARATUS AND CONDUCT O2, EXPLOSIVE
  AND TOXIC TESTS

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APPLICATION OF CLEANING METHODS

• DETERMINE VENTILATION/ PPE REQUIREMENTS FOR TANK
  CLEANING EVOLUTION
• ENSURE VENTILATION/ PPE REQUIREMENTS ARE MET
• PERFORM CONTINUOUS/PERIODIC ATMOSPHERIC TESTS AS
  NEEDED

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APPLICATION OF CLEANING METHODS

• SOME CONSIDERATIONS WHEN TESTING DFM and J-P
  tanks
• HYDROCARBON 2 TUBES USED TO INDICATE PRESENCE /
  ABSENCE OF FUEL VAPORS
• NSTM 074 VOL 3 APPEN E LISTS GASES TO TEST
• HYDROCARBON 2 TEST HAVE A PEL, IDLH IS N/D, IN
  NSTM 074 VOL 3 APPENDIX G

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APPLICATIONS OF CLEANING METHODS

• S, T F ???

SLIPS, TRIPS AND FALLS ARE A LEADING CAUSE OF
MINOR INJURIES IN TANK CLEANING OPERATIONS.
INFORM CLEANING CREW OF ANY OBSTACLES ENCOUNTERED
DURING INITIAL TANK INSPECTION.
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GASOLINE TANKS
-NORMALLY DONE BY SHIPYARD
-IDLH SPACE
-GAS FREE ADJACENT SPACES
-MUST USE STEAM CLEANING
- LEAD HAZARD?
-WATER WASH
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INERTING, PRESSING-UP AND STEAM BLANKETING

• NSTM 074 SECTION 24
• CONTAINS DETAILED PROCEDURES AND REQUIREMENTS FOR
  CONDUCTING EACH EVOLUTION.

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INERTING, PRESSING-UP AND STEAM BLANKETING

• MAY BE USED WHEN HOT WORK IS REQUIRED AND NORMAL
  CLEANING AND GAS FREEING IS IMPOSSIBLE EMERGENCY
  USE ONLY
• NOT FOR USE WITH GASOLINE TANKS
• TOTALLY ISOLATE TANK FROM SURROUNDING SPACES
  INCLUDING COMMON VENTS AND INTERCONNECTING PIPING

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INERTING, PRESSING-UP AND STEAM BLANKETING

• GASES USED
• CO2 (HEAVIER THAN AIR)
• N2 (LIGHTER THAN AIR PREFERRED MEDIUM)
• MAINTAIN lt1 O2 CONCENTRATION
• WORK AREA OUTSIDE SPACE SHALL BE CERTIFIED AND
  MAINTAINED AS SAFE FOR HOT WORK
• DISPOSE OF DISPLACED VAPOR AND INERTING MEDIUM
  SAFELY

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INERTING WITH N2
N2 INLET
PRESSURE GAGE
VENT CONNECTION
NO HOTWORK WITHIN 24 OF RESIDUAL OIL
6 FROM TANK BOTTOM/ LIQUID SURFACE
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PRESSING-UP
-EMERGENCY USE ONLY
-FILL WITH WATER
-ALLOW GASES TO VENT
-MAINTAIN LESS THAN 1 OXYGEN
-DO NOT CONDUCT HOT WORK WITHIN 12 INCHES OF
WATER LEVEL
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STEAM BLANKETING
-EMERGENCY USE ONLY
-COMPLETE SAME AS INERTING
-MONITOR TEMPERATURE (230 DEG MAX)
-START 3 HOURS PRIOR TO HOT WORK
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ALTERNATE REPAIR METHODS

• EPOXY-BASED COMPOUNDS
• RULES OF THUMB
• MAXIMUM SYSTEM PRESSURE MAY NOT EXCEED 300 PSI
• MAXIMUM TEMPERATURE MAY NOT EXCEED 2000F
• ANY CHANGE OR REPAIR TO AN EXISTING SYSTEM OR
  COMPONENT SHOULD BE CONSIDERED A DEPARTURE FROM
  SPECIFICATIONS (DFS) AND REQUIRES TYCOM APPROVAL

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ALTERNATE REPAIR METHODS

• FOLLOWING TYCOM APPROVAL
• THE WORK ITEM WILL REMAIN ON THE CSMP FOR
  TRACKING PURPOSES AND PERMANAENT REPAIRS SHOULD
  BE SCHEDULED FOR COMPLETION AT THE EARLIEST
  OPPORTUNITY

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SUMMARY
We described the following methods of
tank cleaning a) Hot or Cold Water
Wash b) Steam Cleaning c)
Butterworthing / Wheelerizing d) Chemical
Cleaning e) Biological Cleaning  
We described the proper cleaning and testing
processes for safe entry and hot work in the
following types of tanks   a) Diesel Fuel
Marine (DFM) b) JP-5 c) Gasoline
d) Collection, Holding and Transfer (CHT)
e) Closed Compartments   We described the
safety precautions and procedures for performing
emergency hot work on tanks when proper cleaning
cannot be accomplished and the following methods
are used  a) Inerting
b) Pressing-Up c) Steam Blanketing
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REVIEW QUESTIONS
What is the maximum temperature while steam
cleaning?
230 degrees
What is the preferred medium for inerting?
Dry Nitrogen