Before Leaving the Plant

Transcription

1 This document describes how to transfer liquid hydrogen safely and efficiently from a trailer to a customer s tank. Throughout this procedure, valves and connections are numbered according to the standard numbering system used on liquid hydrogen trailers. Refer to the flow diagram and legend on the trailer for valve names and their location on that specific trailer. Refer to Figure1 Generic Flow Diagram for Liquid Hydrogen Trailers Before Leaving the Plant 1. Check the following: 1.1. Customer Billing Ticket (BOL) and DOT Manifest 1.2. Certificate of Conformance (COC) if required 1.3. Gross Weight Ticket based on location s availability of weigh scale 1.4. Review special instructions both for the customer and for the delivery. Take these instructions with you do not discard them 1.5. Routing instructions if needed 2. Check and inspect your personal protective equipment. (PPE) 3. Perform a DOT pre-trip inspection; review and sign the prior trip s Vehicle Inspection Report. (VIR) 4. Check product identification (product 10) 4.1. Shipping papers versus trailer number 4.2. Product name (Hydrogen. Refrigerated Liquid) on all four sides of the trailer 4.3. UN placard (# 1966) on all four sides of the trailer 4.4. Product tag (if required) attached to liquid fill valve (V-1) 5. Check the transfer hose to ensure that it matches the product for the vehicle 6. Inspect the trailer rupture discs by switching the trail rupture disc diverter valve to the opposite (non-service) side. Do so by applying slow, steady pressure to the valve handle. After switching the valve, leave it in that position. 7. Ensure that the trailer vacuum inspection date and pressure test date are current. The date 1 indicated on the trailer is the actual date of the inspection V External visual inspection date. Current date must not be more than one year from inspection date

2 7.2. 2/06 P Pressure test date. Current date must not be more than five years from the test date. 8. Visually inspect the side and rear compartments (piping, valves, etc.), listen for any irregular noises 9. Activate the remote emergency shutoff switches (EV-1, 2, 3) to check the operation of the automatic air valves (A-1 and A-2). 10. Ensure that the road relief regulator valve is activated (V-18) 11. Inspect the spare V-band HQ clamp and fill connection 0 ring seals and gaskets 12. Ensure that all trailer compartments are secured and locked 13. Perform a tug test on the tractor kingpin/fifth wheel to ensure a proper connection 14. If the trailer pressure is above psig because of a trailer fill 48 or more hours prior to the trip start, reduce the pressure by driving the vehicle a short distance and bringing it to a sudden stop at least twice. If the pressure cannot be reduced, contact Customer Service at Monitor and record the ambient (outside) temperature and container pressure of the liquid hydrogen trailer Provide this record to Customer Service at these intervals: Start of each trip At least once every five (5) hours Upon arrival at customer destination Immediately before and after any manual venting Document any deviation from normal operation that occurred during your trip and notify Customer Service 2

3 Upon Arrival at the Customer Site Unloading personnel must remain in attendance and have a clear view of the operating controls at all times while the product is being unloaded. No cell phones or electronic devices are permitted within 25 feet of the trailer operating compartment at any time. 1. Check in with the customer if required Know and comply with the customer s emergency plans (such as evacuation routes and how to summon help in case of a fire, property damage, spill, etc.) 1.2. Know and comply with the customer s site regulations (yard speed limits, signage, railroad crossings, etc.) 2. Proceed to the customer tank area 3. Perform a pre-backing area inspection 3.1. Stop the vehicle and set parking break 3.2. Compare the United Hydrogen number on the customer tank to your shipping papers to ensure you are at the correct location Wear required PPE Safety glasses Safety shoes Hard hat with face shield Long sleeved shirt and cuff less trousers made of 100 percent cotton (Remember to leave trouser legs outside of high topped shoes to shed spilled liquid.) Flame resistant clothing (e.g. Nomex lab coat) Gauntlet gloves that can be quickly thrown off when operating valves and handling hoses 3.4. Perform a walk around inspection to visually check the unloading area to ensure that it is safe to unload Check the customer tank vent line for a possible vent stack fire Do not begin the unloading procedures if a vent stack fire is present. Call Customer Service ( ) and someone will be dispatched to isolate the 3 source and extinguish the flame Ensure the areas to the rear, sides, and above are clear

4 Look for obstructions, tripping hazards, open flames or other source of ignition, and any potential problem areas 3.7. Determine the best location to position the trailer: To ensure that the greatest quantity of product is delivered, evaluate the terrain (high/low spots) around the tank s unloading point Select a level area so that the transfer hoses will easily reach connections on the customer tank. A transfer hose that is crimped or under tension may leak or create other unsafe conditions during the transfer Chose a place that will not compromise your safety, the safety of the public, or the safety of your equipment. 4. Place your safety cones for backing reference and to mark hazards near your approach path to the unloading area. 5. Open and secure operating compartment doors if necessary due to physical obstacles that might prevent this after the trailer is backed into delivery position. 6. Remove chocks, release parking break and back into position Note that several walk around inspections may be necessary to re-establish your cone placement. 7. Set the tractor parking break do not set the trailer air brakes, as this will reduce the air available for air actuated valves. 8. Build air pressure to maximum capacity. 9. Turn off tractor engine if not needed to maintain tractor temperature for sleeper partner or to maintain operating pressure. 10. Chock the vehicle between the tandems 11. Conduct a customer site safety inspection Is there anything that prevents you from proceeding safely with customer-specific delivery instructions for the confirmed United Hydrogen number? 4

5 11.2. Are any of the customer s tank components inaccessible or not functioning? Liquid phase fill valve Gas phase fill valve Gas blow down valve Full trycock Pressure gauge Contents gauge Fill line drain/purge valve Vent stack drain valve Customer ground cable and clamp Tank liquid level and contents gauge inspection. (If the tank contents gauge is not functional or is reading zero level, call Customer Service ( ) to initiate a warm tank investigation procedure. Do not continue with the fill until this investigation is complete.) Be alert for any low points, large depressions, open pits or other areas below grade where heavy/cold gasses can concentrate Wall, buildings, and fences Know and find all entrances and exits from confined or enclosed areas Leave all gates open during the unloading process Identify at least two unobstructed personnel exits leading away from the area for use in an emergency If necessary, obtain the keys from the customer to unlock the gates A concrete transfer pad is required for delivery of liquid hydrogen The pad must be a clean 8 foot by 10 foot (minimum) concrete surface and be free of oil, grease, dirt and other combustion hazards Three (3) feet of work area must be behind the rear compartment area with remaining concrete transfer pad beneath the trailer Ensure that all hose connections that could possibly leak are above the concrete If the customer units do not have a concrete transfer pad, do not begin the fill until it has been discussed with your supervisor and/or a Customer Service representative Temporary transfer surfaces are acceptable for emergency or temporary supply systems to the customer. Clean aluminum plates or similar can be used At this time, if the storage tank vent stack has a manual drain valve, drain the hydrogen 5 vent stack on the storage tank and the trailer of any condensation moisture.

6 12. Delivery Volume Evaluation and Customer Service Notification Obtain the customer tank contents gauge reading and determine if the trailer contents are: Sufficient to complete your planned deliveries Will result in an unplanned balance If you determine that your deliveries will not work out as planned or if you will have a balance remaining after the delivery, contact Customer Service ( ) and relay your product information before making the delivery. This will allow Logistics time to find a customer for the unplanned balance volume or to remove the scheduled stops if there will not be sufficient volume. NnTI= L If your schedule has multiple stops and you will not have sufficient product for all of them, check for special instructions asking you to "hold back" product 13. If equipped, engage the trailer or suspension dump valve (located near the curbside landing gear) which lowers the trailer rear several inches. CAUTION: Ensure that adequate clearance is below the bumper and step before engaging the dump system. 14. Ground the trailer by attaching the customer ground cable to the designated grounding plate on the trailer. 15. Open and secure trailer operating compartment doors if not open already (Step 5) 16. If brake interlock activation significantly reduces air pressure, open trailer air-operated liquid fill and withdrawal automatic valve (A-1) and pressure-building coil liquid phase automatic valve (A-2) by operating remote emergency shutoff switch s (EV-1, 2, 3) at both sides and the rear of the trailer Engage the trailer brake interlock

7 18. Check the customer tank United Hydrogen number and the vehicle number against the numbers on the shipping papers by checking the items listed below: (Each item must match the product name on the shipping papers.) Product name on the trailer Product name on the tag attached to the trailer liquid fill and withdrawal valve (V-1) Product name on the customer tank OSHA product warning decal on the tank If any of these items DO NOT MATCH, call Customer Service ( ) for further assistance. 19. Read and comply with any special instructions that are posted on the customer s tank, especially the Driver Maintain Pressure At. If the tank does not contain this information, call Customer Service. 20. Record the items below in the appropriate Start boxes on your shipping papers: Customer tank content gauge reading Trailer contents gauge reading 21. Ensure that the trailer unloading pressure does not exceed the following pressures during the entire delivery procedure: Hydrogen Trailer Working Pressure Chart APCI Units LHT1 LHT4 45 PSIG 22. Deactivate the trailer road regulator control valve by closing the air operated valve (V-18) located inside the curb side cabinet. 23. Ensure that the trailer liquid fill/withdraw valve (V-1) and pressure building coil liquid phase valve (V-4) located inside the roadside cabinet are tightly closed. 24. Open the trailer air operated liquid fill/withdraw automatic valve (A-1) and pressure building liquid chase valve (A-2) by operating all 3 emergency shutoff valves (EV-1, 2, 3) located on each side and the rear of the trailer by pulling the switch out. Note that all 3 must be out to operate the automatic valves. 7

8 25. Open the drain/purge valve for the liquid/withdraw hose (V- ) located inside the roadside cabinet to drain any residual pressure between the mail liquid fill/withdraw valve (V-1) and the dust cap at the rear of the trailer. 26. Ensure that the customer tank liquid and gas phase valves are closed. 27. Open the customer tank fill line drain/purge valve. A small amount of gas may vent from the purge valve through the vent stack. If gas continues to vent for more than a few seconds, close the purge valve and call Customer Service ( ) for assistance. Otherwise, leave the valve open. 28. When the customer fill line drain/purge valve stops venting, remove the protective dust cap from the trailer and tank connections. Ensure that the trailer connect drain/purge valve (V- ) and the customer fill line drain/purge valve are open before removing the protective dust caps. 29. Inspect these connections for dirt and any foreign material. Wipe them with a clean cloth. Always replace the Buna a-rings on the HQ connections. 30. Inspect the transfer hose nozzle piece and wipe it with a clean cloth to remove any foreign material. Connect it to the appropriate trailer (CP-!) and tank connections. 31. Tighten the trailer connection (CP-!) and the customer tank V-Band HQ connection. Engage the safety catch latch. Be sure the transfer hose vacuum plug is point toward the ground. Caution: Do Not Over Tighten 8

9 32. Vertical Tank Cool Down: Vertical tanks require cool down of the gas piping before filling is started. These tanks have a tendency to produce warm pockets of gas within the internal gas piping. Once formed, the warm gas pockets will cause a rapid pressurization of the tank. This can happen in seconds, resulting in the pressure relief valves and/or the rupture disc malfunctioning and causing damage to the disc. 33. How to cool down the tank s gas piping: Open the tank fill vent/purge valve (should already be open from hooking up the transfer hose) Open the tank gas chase fill valve one turn for five (5) minutes. Cool gas will flow from the tank through the gas piping via the purge valve to the vent stack After five (5) minutes, close the tank gas phase fill valve and vent/purge valve; cool down is complete. 34. If trailer pressure is less than 45 psig, increase the pressure to 45 psig by completely opening the pressure building coil gas chase valve (V-5) and slightly opening the pressure building coil liquid phase valve (V-4). 35. Close the trailer connection drain/purge valve (V- ) 36. Trailer transfer hose sweep purge procedure: Slowly open the trailer fill/withdraw valve (V-1) Sweep purge the transfer hose for three (3) to five (5) minutes through the customer fill line drain/purge valve located on the customer s tank Close the customer tank drain/purge valve Close the trailer liquid fill/withdraw valve (V-1) 37. If any leaks are found during the purge: Isolate the transfer hose. Close the trailer liquid fill/withdraw valve (V-1) Relieve the pressure in the hose by carefully opening the drain/purge valve that is farthest from the leaking connection until the hose is depressurized Hand tighten the V-Band HQ clamp and the trailer connection (APCI-Air Force) then repressurize and check for leaks. If no leaks are found proceed to step 38. If a leak is found, go back to step 37.2 then to step Disassemble the connection and replace the Buna O-rings and inspect the nozzle seal. 9 Replace if necessary After correcting leaks, close the drain/purge valves and return to step 36.

10 38. Transfer Hose Pressure Procedure: Open the trailer liquid fill/withdraw valve (V-1) Open the customer tank drain/purge valve for 15 seconds then close the valve Close the liquid fill/withdraw valve (V-1) Open the customer tank drain/purge valve venting the hose then close it leaving a slight residual pressure in the hose/piping Repeat steps seven (7) more times for a total of eight (8) pressure purges and one (1) sweep purge. Verify customer tank pressure is below MAWP of trailer If it is not, lower the customer tank pressure by venting it down below trailer MAWP this should be between psig to obtain normal flow of liquid. Note: If you must lower the customer s tank pressure below the set point of their pressure build up coil, you must shutoff the liquid supply valve to the customer s pressure build up coil or the pressure in the tank will not reduce. 39. Once you have verified that the customer s tank pressure is below MAWP of the trailer, slowly open the customer s liquid and/or gas phase fill valves to obtain normal full flow. Note: Loading the customer s tank thru the liquid (bottom) phase valve will raise the tank pressure in the customer s tank. Loading through the gas phase valve (top) will lower the customer s tank pressure. 40. Open the trailer liquid fill/withdraw valve (V-1). 41. Unloading of liquid products from your trailer requires your constant attention and evaluation of customer s tank pressure and level. Your trailer pressure and level as well. Do not allow the customer s tank pressure to exceed the MAWP of your trailer. Use the customer tank blow down valve and/or the trailer blow down valve (V-2) to reduce pressure preventing the relief valves from operating. 42. When the customer tank liquid level gauge approaches full, open the customer tank Trycock valve and watch the color-faced full termination gauge and the tank pressure gauge. The tank is full when the customer tank pressure gauge beings to rise (preferred method) or the needle on the color-face fill termination gauge reaches the red area Stop the transfer of liquid by operating the emergency stop switch (EV-1, 2, 3) to close the air operated automatic valve (A-1, 2) switches located on each side and the rear of the trailer. These are operated by pushing the knob in.

11 44. Close the customer liquid phase (bottom fill) valve and leave the gas phase (top fill) valve open. 45. Close the full Trycock valve. 46. Close the trailer pressure building coil liquid phase valve (V-4). 47. Close the trailer pressure building coil gas phase valve (V-5). 48. Close the trailer liquid fill/withdraw valve (V-1). 49. Record the trailer liquid level from the level gauge (LLI-1) on your shipping papers. 50. Close the customer tank gas phase (top fill) valve. 51. Vent the transfer hose pressure to the vent stack. Open the customer tank fill connection vent and/or trailer connection drain/purge valve (V- ). 52. Check the readings on the trailer pressure and liquid level gauges to determine the travel time to your next stop or return to the fill plant. Road relief regulators on APCI unit (LHT1-4) are set at 35 PGIG. If the trailer must be blown down before leaving the customers site refer to the following: If required to blow down trailer, open the trailer gas phase blow down valve (V-2) and vent until the trailer is below 35 PSIG Also open the pressure building coil gas phase valve (V-5) to verify that no excess pressure is trapped within the building coil Close both the gas phase pressure coil valve (V-5) and the trailer gas phase valve (V-2). 53. After the transfer hose stops venting (approximately minutes): Loosen the V-Band clamp from the hose connection at the customer tank Pull the hose out slightly (about 2 inches) Observe for excess pressure or liquid. If there is excess pressure or liquid, STOP and allow the hose to vent completely Disconnect the hose from the trailer (pointing the end of the hose down and away from 11 you as you remove it from the connection) Inspect the transfer hose ends before installing the dust caps Stow the transfer hose in the hose transporting tube located on the side of the trailer.

12 53.7. Secure the customer tank connection dust cap Secure the trailer dust cap on the liquid fill/withdraw connection. 54. Close all drain purge valves on customer tank and trailer (V- ). 55. Leak test the trailer fill/withdraw connection dust cap in the following manner: Remove air from the fill/withdraw connection point by slight opening the liquid fill/withdraw manual valve (V-1) and checking the dust cap connection for leaks If no leaks are found, open the liquid fill/withdraw drain/purge valve (V- ) to vent any pressure between the liquid fill/withdraw valve (V-1) and the dust cap If a leak is found, vent any pressure by opening the liquid fill/withdraw valve (V- ) then remove the dust cap and inspect the Buna O-Ring (replace if necessary), re-tighten dust cap and leak test again. (Step 55) 56. Check all other trailer valves to be sure they are secure and tightly closed. 57. Check that all other customer tank valves that were either opened or closed (pressure building coil) are returned to the manner in which they were when you arrived. 58. De-activate the trailer brake interlock system by resetting all emergency stop switches (EV- 1, 2, 3) and the connection switch located at the rear of the trailer. 59. Activate the Road Relief Regulator valve (V-18) located inside the curb side compartment. 60. Remove grounding cable/strap from the trailer. 61. Close all compartment doors and secure them. 62. Complete all paperwork and have customer sign or leave a copy at customer s site. 63. If you have product remaining in the trailer, but do not have another scheduled stop, call Customer Service ( ). 64. Visually inspect all areas around the trailer and the trailer itself to ensure that nothing has changed during the unloading time Remove and stow all wheel chocks and safety cones.

13 66. If additional trailer shakedown is required: Reduce pressure by driving a short distance and bring the trailer to a sudden stop. Repeat this at least two (2) times and record the pressure drop after several minutes If this does NOT drop the trailer pressure enough, then re-position the trailer at the customer tank and perform the following: Connect the grounding cable/strap Place wheel chocks between tandems on the trailer Open compartment doors Open the trailer gas phase blow down valve (V-2) Relieve trailer pressure to desired level Close trailer gas phase blow down valve (V-2) Close compartment doors Remove grounding cable/strap Stow wheel chocks and safety cones. 67. Record trailer pressure and the ambient temperature. 68. Proceed to next stop or filling plant. 13

14 Abnormal Situations Excessive pressure rise on an empty trailer: - A pressure rise of five (5) PSIG for every two (2) hours of travel time is considered excessive. If your destination is great than the travel time it takes for the trailer to rise to 45 PSIG, contact Customer Service ( ) for instructions. Excessive pressure rise on a full trailer: - A pressure rise of 0.2 PSIG for every two (2) hours of travel time is considered excessive. Since 0.2 PSIG is very difficult to see on a trailer pressure gauge, use one (1) PSIG. This situation can be critical. Contact Customer Service ( ) with your location, pressure and temperature readings. Initial fills of customer tanks/refill of empty hot tanks : - 4,500 gallon or smaller do not fill more than ½ full. This will allow the liquid to expand in the tank as the tank continues to cool down and warms the liquid up. - Larger tanks do not fill more than ¾ full. This will allow the liquid in the tanks to expand as the tank continues to cool down and the liquid warms up. 14