CNG MAINTENANCE

For every task in CNG Maintenance, 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 in accordance with local, state, and federal safety and environmental regulations.

VII. CNG MAINTENANCE  
A. General  
1. Interpret and verify complaint; determine needed repairs. P-2
2. Follow manufacturer's maintenance schedule to ensure fluids and lubricants are at proper levels and serviced with recommended products. P-2
3. Identify the process of recertification or replacement of fuel supply container(s) according to most current regulations (e.g., NGV-2, DOT); complete documentation; remove and replace fuel supply container, if required. P-2
4. Inspect fuel supply container(s) and brackets as it relates to certification: data plate, working pressures, fuel supply container damage, valves, bolts, torque specifications, and all sealing and venting equipment. P-1
5. Inspect air filters and fuel filter; service or replace as needed. P-2
6. Inspect and ensure that all required emission control devices are present and functional. P-1
    
VII. CNG MAINTENANCE  
B. CNG Fuel Storage and Delivery  
1. Interpret and verify complaint; determine needed repairs. P-2
2. Inspect, adjust, and test manual shut-off valve, service valve, check-valves, and solenoid valves; repair or replace as needed. P-1
3. Empty fuel supply container according to manufacturer's procedures and all local, state and federal regulations. (Local procedures will vary and extreme care must be exercised if using actual fuel. Use of inert gas is recommended for this task.) P-1
4. Inspect and test fuel selection system components; repair or replace as needed. P-2
5. Select and install swage, compression, flare, captive O-ring, NPT, and other fittings using manufacturer's recommended sealants when required. P-1
    
VII. CNG MAINTENANCE  
C. CNG A/F Management  
1. Interpret and verify complaint; determine needed repairs. P-2
2. Check for fuel system problems caused by fuel contamination. P-3
3. Check air/fuel system integrity (e.g., fuel leaks, air leaks, components compatibility/application); determine needed repairs. P-2
4. Inspect and test fuel pressure regulation system components; adjust, repair or replace as needed. P-2
5. Remove, clean, and reinstall throttle assemblies; adjust related linkages as needed. P-3
6. Check/adjust idle speed and fuel mixtures according to manufacturer's procedures. P-2
    
VII. CNG MAINTENANCE  
D. CNG Fuel Storage and Handling  
1. Interpret and verify complaint; determine needed repairs. P-2
2. Perform safe fueling procedures and determine fuel level. P-1
3. Identify working pressures and demonstrate an understanding of fuel characteristics as they relate to temperature and fill procedures. P-1
4. Empty fuel system using industry practices or manufacturer's procedures and all local, state and federal regulations. (Local procedures will vary and extreme care must be exercised if using actual fuel. Use of inert gas is recommended for this task.) P-1

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