MODULE 7

1. MODULE 7 Unload a Cargo Tank Motor Vehicle (CTMV)

2. Module 7 – Unload a Cargo Tank Motor Vehicle (CTMV) • When a cargo transport delivers propane. • When a bobtail must be emptied of liquid.

3. Module 7 – Unload a Cargo Tank Motor Vehicle (CTMV) Tasks include: • Verify room in bulk storage tanks. • Position the CTMV. • Connect the liquid and vapor hoses, and check for leaks. • Start the transfer. • End the transfer. • Carefully bleed down liquid trapped in the riser and hose. • Disconnect and store the hoses.

4. LESSON 1 Characteristics of Bulkheads and Plant Piping

5. Lesson 1 – Characteristics of Bulkheads and Plant Piping • Bulkhead components: – Liquid connections. – Vapor connections. – Breakaway system. • May have hoses attached.

6. Breakaway Systems • Predictable breakaway point. • Means to limit flow of propane.

7. Emergency Shutdown System • Not less than 25 feet or more than 100 feet from any liquid transfer point.

8. Lesson 2 Characteristics of CTMVs

9. Lesson 2 – Characteristics of CTMVs • Gauges • Valve operators

10. Liquid and Vapor Connections Cargo Transport Bobtail

11. Liquid and Vapor Connections Connections NOT used when unloading Cargo Transport Bobtail

12. 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.

13. Lesson 3 Hazards and Precautions

14. 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.

15. Hazards and Precautions for All Propane Transfers • When? • Where? • Metered delivery service. • Other than metered. • Definition of “qualified person”?

16. 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.

17. Other Potential Hazards • Auto Refrigeration – Details in Lessons 7, 8 & 10. • Multiple storage tanks of different diameters.

18. 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

19. Lesson 4 Measure the Liquid Level in a Tank

20. Lesson 4 – Measure the Liquid Level in a Tank Float Gauge Rotary Gauge

21. Lesson 5 Determine the Amount of Propane to be Unloaded

22. Lesson 5 – Determine the Amount of Propane to be Unloaded

23. 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.

24. Determine the Available Capacity in Storage Tanks • Determine maximum permitted filling level (MPFL) for each available tank • Calculate gallons of liquid propane that can be added to each available tank: • Record % liquid volume in each tank • % available capacity = MPFL – current % volume • Gallons available capacity = % available capacity x WC in gallons • Add gallons that can be added to all available storage tanks

25. 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.

26. Learning Activity – Calculating Available Capacity in Bulk Storage Tanks

27. Lesson 6 Unload a Bobtail Using the Bobtail Pump

28. Lesson 6 – Unload a Bobtail Using the Bobtail Pump

29. Position the Bobtail • Level gauges visible. • Shutoff valves accessible. • 10 ft. from container. • Set parking brake. • Turn off electrical devices. • Wheel chocks.

30. Connect the Hoses and Check for Leaks • Connection depends on bulkhead configuration. • Vapor equalization recommended.

31. 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

32. 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.

33. Lesson 7 Safely Disconnect the Bobtail Liquid Hose

34. 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.

35. Avoid Auto-Refrigeration When Bleeding Down a Riser

36. Avoid Auto-Refrigeration When Bleeding Down a Riser

37. Avoid Auto-Refrigeration When Bleeding Down a Riser

38. Avoid Auto-Refrigeration When Bleeding Down a Riser

39. Avoid Auto-Refrigeration When Bleeding Down a Riser

40. Avoid Auto-Refrigeration When Bleeding Down a Riser

41. 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.

42. Disconnect and Store the Hoses • Loosen vapor connection - relieve pressure. • When both connections fully depressurized: • Disconnect bobtail hose end valve from bulkhead adapter. • Disconnect vapor hose from bobtail vapor connection. • If not permanently connected to bulkhead, disconnect vapor hose from bulkhead and store. • Inspect bobtail hose as it is reeled in. • Remove adapter and store. • Replace caps. • Complete forms as required.

43. Lesson 8 Empty the Bobtail Liquid Hose

44. 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

45. 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.

46. 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.

47. Venting a Bobtail Hose

48. Venting a Bobtail Hose

49. Venting a Bobtail Hose Frost may not appear. May occur in center of hose reel.

50. Venting a Bobtail Hose • 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.