2011 PLANT OPERATIONS MODULE 7 Unload a Cargo Tank Motor Vehicle (CTMV)
Dec 23, 2015
2011 PLANT OPERATIONS
MODULE 7
Unload a Cargo Tank Motor Vehicle (CTMV)
2011 PLANT OPERATIONS
Module 7 – Unload a Cargo Tank Motor Vehicle (CTMV)
• When a cargo transport delivers propane.
• When a bobtail must be emptied of liquid.
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2011 PLANT OPERATIONS
Module 7 – Unload a Cargo Tank Motor Vehicle (CTMV)
Tasks include:
1. Verify room in bulk storage tanks.
2. Position the CTMV.
3. Connect the liquid and vapor hoses, and check for leaks.
4. Start the transfer.
5. End the transfer.
6. Carefully bleed down liquid trapped in the riser and hose.
7. Disconnect and store the hoses.
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2011 PLANT OPERATIONS
LESSON 1
Characteristics of Bulkheads and Plant Piping
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LESSON 1
2011 PLANT OPERATIONS
Lesson 1 – Characteristics of Bulkheads and Plant Piping
• Bulkhead components:
– Liquid connections.
– Vapor connections.
– Breakaway system.
• May have hoses attached.
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LESSON 1
2011 PLANT OPERATIONS
Breakaway Systems
• Predictable breakaway point.
• Means to limit flow of propane.
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LESSON 1
2011 PLANT OPERATIONS
Emergency Shutdown System
• Not less than 25 feet or more than 100 feet from any liquid transfer point.
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2011 PLANT OPERATIONS
Lesson 2
Characteristics of CTMVs
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LESSON 2
2011 PLANT OPERATIONS
Lesson 2 – Characteristics of CTMVs • Gauges
• Valve operators
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LESSON 2
2011 PLANT OPERATIONS
Liquid and Vapor Connections
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Cargo Transport Bobtail
LESSON 2
2011 PLANT OPERATIONS
Liquid and Vapor Connections
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Cargo Transport Bobtail
Connections NOT used when unloading
LESSON 2
2011 PLANT OPERATIONS
Emergency Activation System
• Bobtail with WC ≤ 3500 gallons, in metered delivery service.
• Bobtail with WC > 3500 gallons, in metered delivery service.
• CTMV other than metered delivery service.
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2011 PLANT OPERATIONS
Lesson 3
Hazards and Precautions
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LESSON 3
2011 PLANT OPERATIONS
Lesson 3 – Hazards and Precautions
• Remove ignition sources, flammable liquids and combustible materials to a safe distance.
• Observe precautions within Static Discharge Control Area.
• Wear appropriate PPE.
• Inspect hoses and fittings.
• Emergency evacuation procedures, and adequate egress locations.
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LESSON 3
2011 PLANT OPERATIONS
Hazards and Precautions for All Propane Transfers
• When?
• Where?
Metered delivery service. Other than metered.
• Definition of “qualified person”?
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LESSON 3
2011 PLANT OPERATIONS
Valves and Hoses
• Inspect hoses before use.
• When moving hoses
– Avoid dragging.
– Carry valves by the body.
– Aim valve outlet away from yourself and others.
• Know locations of ESVs.
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LESSON 3
2011 PLANT OPERATIONS
Other Potential Hazards
• Auto Refrigeration – Details in Lessons 7, 8 & 10.
• Multiple storage tanks of different diameters.
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LESSON 3
2011 PLANT OPERATIONS
When Equipment Malfunctions Occur
• Lock-out/Tag-out
– May be unsafe to transfer propane
• Tag identifies
– Who locked the device
– Why it was locked
– What must be done before the device can be returned to service
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2011 PLANT OPERATIONS
Lesson 4
Measure the Liquid Level in a Tank
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LESSON 4
2011 PLANT OPERATIONS
Lesson 4 – Measure the Liquid Level in a Tank
Float Gauge
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Rotary Gauge
2011 PLANT OPERATIONS
Lesson 5
Determine the Amount of Propane to be Unloaded
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LESSON 5
2011 PLANT OPERATIONS
Lesson 5 – Determine the Amount of Propane to be Unloaded
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LESSON 5
2011 PLANT OPERATIONS
Verify the Contents of a Cargo Tank
• Check bill of lading to insure cargo tank contains propane.
• Verify presence of odorant.
• Check temperature and pressure readings.
• Record % liquid volume in cargo tank.
• % liquid volume x WC = gallons of liquid propane in cargo tank.
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LESSON 5
2011 PLANT OPERATIONS
Determine the Available Capacity in Storage Tanks
1. Determine maximum permitted filling level (MPFL) for each available tank
2. Calculate gallons of liquid propane that can be added to each available tank:
Record % liquid volume in each tank % available capacity = MPFL – current % volume
3. Gallons available capacity = % available capacity x WC in gallons
4. Add gallons that can be added to all available storage tanks
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LESSON 5
2011 PLANT OPERATIONS
Example – 30,000 gallon tank
• MPFL = 80%.
• Current Level = 69%.
• Available capacity = 80% - 69% = 11%.
• Gal available capacity = 11% x 30,000 gal = 3,300 gallons.
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LESSON 5
2011 PLANT OPERATIONS
Learning Activity – Calculating Available Capacity in Bulk Storage Tanks
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2011 PLANT OPERATIONS
Lesson 6
Unload a Bobtail Using the Bobtail Pump
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LESSON 6
2011 PLANT OPERATIONS
Lesson 6 – Unload a Bobtail Using the Bobtail Pump
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LESSON 6
2011 PLANT OPERATIONS
Position the Bobtail
• Level gauges visible.
• Shutoff valves accessible.
• 10 ft. from container.
• Set parking brake.
• Turn off electrical devices.
• Wheel chocks.
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LESSON 6
2011 PLANT OPERATIONS
Connect the Hoses and Check for Leaks
• Connection depends on bulkhead configuration.
• Vapor equalization recommended.
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LESSON 6
2011 PLANT OPERATIONS
Start the Transfer
• If required, set meter
• Open discharge valves
– Open last valve slowly
• Engage PTO
• Monitor storage tank levels
• Stop immediately if:
– Leak
– Abnormal sounds from pump
– EFV slugs
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LESSON 6
2011 PLANT OPERATIONS
End the Transfer
• Stop bobtail pump when:
Cargo tank reaches empty. All storage tanks reach MPFL.
• Close liquid and vapor valves on bulkhead and cargo tank.
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2011 PLANT OPERATIONS
Lesson 7
Safely Disconnect the Bobtail Liquid Hose
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LESSON 7
2011 PLANT OPERATIONS
Lesson 7 – Safely Disconnect the Bobtail Liquid Hose
• Recognize hazards posed by auto refrigeration.
• Avoid the condition when bleeding down a riser.
• Recognize the condition when it occurs, and act to avoid the hazards.
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LESSON 7
2011 PLANT OPERATIONS
Avoid Auto-Refrigeration When Bleeding Down a Riser
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LESSON 7
2011 PLANT OPERATIONS
Avoid Auto-Refrigeration When Bleeding Down a Riser
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LESSON 7
2011 PLANT OPERATIONS
Avoid Auto-Refrigeration When Bleeding Down a Riser
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LESSON 7
2011 PLANT OPERATIONS
Avoid Auto-Refrigeration When Bleeding Down a Riser
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LESSON 7
2011 PLANT OPERATIONS
Avoid Auto-Refrigeration When Bleeding Down a Riser
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LESSON 7
2011 PLANT OPERATIONS
Avoid Auto-Refrigeration When Bleeding Down a Riser
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LESSON 7
2011 PLANT OPERATIONS
How to Avoid the Hazard
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• Be patient when bleeding trapped liquid.
• Chance of auto-refrigeration increases as wetted surface area decreases.
• Frost? - Close the valve or adapter and wait.
• Auto-refrigeration can occur without frost .
• Follow these precautions:
– Always disconnect slowly.– Keep hands and face away from
connection.– Wear PPE.– Don't point hose at yourself or anyone else.
LESSON 7
2011 PLANT OPERATIONS
Disconnect and Store the Hoses
1. Loosen vapor connection - relieve pressure.
2. When both connections fully depressurized:
Disconnect bobtail hose end valve from bulkhead adapter.
Disconnect vapor hose from bobtail vapor connection.
3. If not permanently connected to bulkhead, disconnect vapor hose from bulkhead and store.
4. Inspect bobtail hose as it is reeled in.
5. Remove adapter and store.
6. Replace caps.
7. Complete forms as required.
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2011 PLANT OPERATIONS
Lesson 8
Empty the Bobtail Liquid Hose
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LESSON 8
2011 PLANT OPERATIONS
Lesson 8 – Empty the Bobtail Liquid Hose
• If bobtail hose must be disconnected to permit servicing.
• May use scavenging system to transfer liquid into a container, or
• May be necessary to vent the hose to atmosphere.
– Repeatedly open and close hose end valve
– Auto-refrigeration difficult to avoid
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LESSON 8
2011 PLANT OPERATIONS
Venting a Bobtail Hose
• Before opening hose end valve:
– Shut off bobtail’s engine.
– Shut off supply from cargo tank to hose reel.
– Remove all ignition sources, flammable liquids and combustible materials to a safe distance.
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LESSON 8
2011 PLANT OPERATIONS
Venting a Bobtail Hose
• Potential for auto-refrigeration is affected by:
– How long hose end valve is left open during each interval –short is better.
– Recovery time allowed between openings – more is better.
– Surrounding air temperature and dew point
– Sunlight shining on the hose – more is better.
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LESSON 8
2011 PLANT OPERATIONS
Venting a Bobtail Hose
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LESSON 8
2011 PLANT OPERATIONS
Venting a Bobtail Hose
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LESSON 8
2011 PLANT OPERATIONS
Venting a Bobtail Hose
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Frost may not appear.May occur in center of hose reel.
LESSON 8
2011 PLANT OPERATIONS
Venting a Bobtail Hose
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• Consider leaving the hose end valve open to allow vaporization to continue.
– No ignition sources within 25 feet of the hose end valve.
– With hose end valve outdoors, leave open to allow venting to continue.
– Remain in attendance until venting is finished.
– Do not rewind empty hose on reel.
2011 PLANT OPERATIONS
Lesson 9
Unload a Cargo Transport Using the Transport Pump
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LESSON 9
2011 PLANT OPERATIONS
Lesson 9 – Unload a Cargo Transport Using the Transport Pump
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LESSON 9
2011 PLANT OPERATIONS
Position the Cargo Transport
• Level gauges visible.
• Shutoff valves accessible.
• 10 ft. from container.
• Tank level for accurate reading.
• Align the tractor and trailer .
• Set parking brake.
• Turn off electrical devices.
• Wheel chocks.
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LESSON 9
2011 PLANT OPERATIONS
Connect the Hoses and Check for Leaks
• Connection depends on bulkhead configuration.
• With shutoff valves closed, remove caps.
• Inspect connectors and hoses.
• Connect hoses.
• Check each connection for leaks.
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LESSON 9
2011 PLANT OPERATIONS
Start the Transfer
• Open valves on transport to equalize pressure
• Open remaining vapor and liquid valves
– Open last liquid valve slowly
• Start pump
• Monitor storage tank levels
• Stop immediately if:
– Leak
– Abnormal sounds from pump
– EFV slugs
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LESSON 5
2011 PLANT OPERATIONS
End the Transfer
• Stop transport pump when:
– Cargo tank reaches empty.
– All storage tanks reach MPFL.
• Close liquid and vapor valves on bulkhead and cargo tank.
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2011 PLANT OPERATIONS
Lesson 10
Safely Disconnect the Transport Liquid Hose
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LESSON 10
2011 PLANT OPERATIONS
Lesson 10 – Safely Disconnect the Transport Liquid Hose
• Recognize hazards posed by auto refrigeration.
• Avoid the condition when bleeding down a riser.
• Recognize the condition when it occurs, and act to avoid the hazards.
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LESSON 10
2011 PLANT OPERATIONS
How Auto-Refrigeration Can Develop
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LESSON 10
2011 PLANT OPERATIONS
How Auto-Refrigeration Can Develop
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LESSON 10
2011 PLANT OPERATIONS
How Auto-Refrigeration Can Develop
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LESSON 10
2011 PLANT OPERATIONS
How Auto-Refrigeration Can Develop
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LESSON 10
2011 PLANT OPERATIONS
How Auto-Refrigeration Can Develop
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LESSON 10
2011 PLANT OPERATIONS
Learning Activity
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LESSON 10
2011 PLANT OPERATIONS
How to Avoid the Hazard
• Be patient when bleeding trapped liquid.
• Chance of auto-refrigeration increases as wetted surface area decreases.
• Frost? - Close the valve or adapter and wait.
• Auto-refrigeration can occur without frost.
• Follow these precautions:
– Always disconnect slowly.
– Keep hands and face away from connection.
– Wear PPE.
– Don't point hose at yourself or anyone else.
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LESSON 10
2011 PLANT OPERATIONS
Disconnect and Store the Hoses
1. Loosen vapor connection - relieve pressure.
2. When both connections fully depressurized disconnect liquid and vapor hoses from transport and bulkhead.
3. Replace caps.
4. Store hoses.
5. Complete forms as required.
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LESSON 10
2011 PLANT OPERATIONS
Case Study – Handling Valves and Hoses
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LESSON 10
2011 PLANT OPERATIONS
Summary
1. Verify room in storage tanks to hold contents of CTMV.
2. Position CTMV.
3. Connect liquid and vapor hoses, and check for leaks.
4. Start transfer, and monitor tank levels.
5. End transfer when cargo tank is empty or storage tanks are full.
6. Don’t let pump run dry.
7. Carefully bleed down liquid trapped in riser and hose.
8. Disconnect and store hoses.
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LESSON 10
2011 PLANT OPERATIONS
Summary
• Avoid most common causes of accidents.
– Venting trapped product too rapidly.
o auto-refrigeration. o uncontrolled release of liquid propane.
– Failure to remain in attendance during the entire transfer.
– Failure to check for leaks and check hoses and fittings for damage or wear.
– Failure to verify ESVs.
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2011 PLANT OPERATIONS
Module 7 Quiz
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