List of Figures Figure 1. Unsealed conduit or pipes passing through walls or ceilings present a potential path of migration... 9 Figure 2. Structural members passing through a wall present a potential path of migration........................... 10 Figure 3. Gaps between walls and the corrugated ceiling panels present a potential path of migration........... 10 Figure 4. Wall penetrations properly sealed to prevent migration ................................................................. 10 Figure 5. A potential path of migration created by an open passageway ....................................................... 10 Figure 6.
Examples of stairways to upper levels that are potential paths of migration.................................... 10 Figure 7. A pass-through window presents a potential path of migration....................................................... 11 Figure 8. Roof-mounted upblast fan........................................................................................................... 12 Figure 9. Direct fan intake with louvers....................................................................................................... 12 Figure 10. Intake ducting used to evacuate air from specific areas............................................................... 12 Figure 11.
Non-compliant fan has fan intake flowing over the motor............................................................. 13 Figure 12. Ground-mounted fan with external ducting.................................................................................. 13 Figure 13. Ceiling configuration with “pockets”........................................................................................... 14 Figure 14. Security mesh in overhead doors............................................................................................... 14 Figure 15. In-wall louver that provides make-up air flow............................................................................... 14 Figure 16.
Powered sidewall fan that provides make-up air flow.................................................................... 14 Figure 17. Conventional fuel maintenance facility ventilation pickup points.................................................... 15 Figure 18. Gas-fired infrared tube-type heater needs to be replaced or removed........................................... 16 Figure 19. Electric infrared radiant heater needs to be replaced or removed................................................. 16 Figure 20. Floor-mounted portable propane heater should be eliminated...................................................... 16 Figure 21.
Gas-fired fan heater needs to be replaced or removed................................................................. 16 Figure 22. Relocating multiple conduits, such as those shown here, would be costly and complex................. 17 Figure 23. Low-voltage wiring and devices................................................................................................... 17 Figure 24. Overhead lighting fixture and ballast that must be relocated........................................................ 18 Figure 25. An overhead rotary fan that presents a potential ignition source.................................................. 18 Figure 26.
A typical electric door motor...................................................................................................... 18 Figure 27. A typical overhead crane............................................................................................................ 18 Figure 28. Typical infrared combustible gas detection head......................................................................... 19 Figure 29. A ceiling-mounted combustible gas detection head...................................................................... 20 Figure 30. Gas detector calibration tubing..................................................................................................
20 Figure 31. Examples of alarm status lights and horn panels (external and internal)....................................... 20 Figure 32. A combustible-gas detection system control panel...................................................................... 21 Figure 33. A typical emergency generator installation.................................................................................. 22 Figure 34. Example of a preliminary facility layout presenting proposed equipment........................................ 23 Figure 35. Typical hand-held portable methane detector.............................................................................. 23 Figure 36.
A defueling post........................................................................................................................ 24 Figure 37. A defueling station that defuels to a CNG station........................................................................ 24 Figure 38. The exhaust from a natural gas engine is hotter than that from a diesel engine, so some exhaust extractor hoses may need to be replaced during the facility modifications. ....................... 25 Figure 39. Typical mezzanine and adjacent storage areas............................................................................ 25 Figure 40.
Representation of Clean Energy’s “Easy Bay”............................................................................. 25 Figure 41. Electrically controlled main gas shut-off valve............................................................................. 26 Figure B1. Critical decision path of a CNG vehicle maintenance facility modification...................................... 33 COMPRESSED NATURAL GAS VEHICLE MAINTENANCE FACILITY MODIFICATION HANDBOOK 2