CNG ON-BOARD FUEL STORAGE AND DELIVERY SYSTEMS *

For every task in CNG On-Board Fuels Storage and Delivery Systems, the following safety requirement must be strictly enforced: Comply with personal and environmental safety practices associated with clothing; eye protection; hand tools; power equipment; proper ventilation; and the handling, storage, and disposal of chemicals/materials in accordance with local, state, and federal safety and environmental regulations.

X. CNG ON-BOARD FUEL STORAGE AND DELIVERY SYSTEMS

A. DIAGNOSIS AND REPAIR

1. Interpret and verify complaint; establish a strategy for diagnosis and repair. P-1

2. Check non-fuel system components such as drive away protection, fire suppression, and leak detection devices. Verify that they are not interfering with the operation of the fuel delivery system. P-2

3. Check fuel system components to include fuel lock-off, valves, solenoids, manual shut-off, connections, fittings, hoses and tubing for leaks, wear, and appropriate installation; service as needed. P-1

4. Check fuel system components to include fuel lock-off(s), valves, solenoids, manual shut-off, and regulator(s) for proper operation; service as needed. P-1

5. Diagnose the cause of fuel odor or fuel loss by inspecting or testing the fuel supply system components (e.g., valves, fuel supply container, pressure relief device, tubing and hoses); service as needed. P-1

6. Diagnose the cause of inaccurate fuel level indicator reading; service as needed. P-2

7. De-fuel fuel system using industry practices or manufacturer's procedures following all local, state, and federal regulations. (Local procedures may vary and extreme care must be exercised if using actual fuel. Use of inert gas or shop air is recommended for practicing this task in the classroom.) P-1

8. Isolate components of the fuel system and de-pressurize affected section before making repairs. P-1

9. Inspect fuel supply container(s) and related hardware (includes brackets, shielding and fasteners) for chaffing or other damage according to manufacturer's procedures; service as needed. P-1

10. Purge and pressurize fuel supply container with inert gas for purpose of repair, shipment or replacement. P-2

11. Check fuel system operating pressures and diagnose cause of abnormal pressures; service as needed. P-1

12. Test on-board methane leak detection system, verify operation; repair or replace as needed (service may require special training and certification). P-3

13. Inspect on-board fire suppression system, verify readiness; repair or replace as needed (service may require special training and certification). P-3

14. Operate/read portable leak detector. P-1

15. Diagnose incorrect heat exchanger operation (including check coolant flow and routing). Check heat exchanger for coolant/fuel cross leaks. P-1

X. CNG ON-BOARD FUEL STORAGE AND DELIVERY SYSTEMS B. MAINTENANCE

1. Inspect fuel system, document findings and any abnormal or unsafe conditions identified during maintenance procedures; recommend further service as needed. P-1

2. Inspect fuel supply container(s) and related hardware (includes brackets, shielding and fasteners) for chaffing or other damage according to manufacturer's procedures; service as needed. P-1

3. Visually inspect that data labels and other decals are in accordance with applicable regulation; replace as needed. P-1

4. Identify and inspect fill circuit components; perform necessary maintenance. P-1

5. 5. Identify and inspect fuel pressure gauge; perform necessary maintenance. P-2

6. Identify and inspect fuel supply container manual shut-off valve, service valve, check-valves, and solenoid valves; perform necessary maintenance. P-1

7. Identify and inspect high pressure regulator(s); perform necessary maintenance (including cooling system service). P-1

8. Identify and inspect secondary pressure regulator(s) (when applicable); perform necessary maintenance. P-2

9. Identify and inspect manual shut-off valve(s) (1/4 turn valve); perform necessary maintenance. P-1

10. Identify and inspect fuel supply container pressure relief device(s) (PRD); perform necessary maintenance. P-1

11. Identify and inspect vent system (when applicable); perform necessary maintenance. P-3

12. Operate/read portable leak detector. P-1

13. Inspect fuel system for leaks. P-1

14. Perform safe fueling procedures. Calculate percent fill based on temperature and pressure. P-2

15. Test on-board methane leak detection system, verify operation; repair or replace as needed (service may require special training and certification). P-3

16. Inspect on-board fire suppression system, verify readiness; repair or replace as needed (service may require special training and certification). P-3

17. Close manual shut-off valve, de-pressurize fuel delivery system, service fuel filter elements and inspect for debris. P-1

18. De-fuel fuel system using industry practices or manufacturer's procedures following all local, state and federal regulations. (Local procedures may vary and extreme care must be exercised if using actual fuel. Use of inert gas or shop air is recommended for practicing this task in the classroom.) P-1

19. Remove or replace fuel supply containers according to manufacturer's specifications. P-2