Page 37 - ESP Participant Guide_Neat

Module 4: NGV Safety Practices and Procedures

Lesson 4.1: Safety Practices and Procedures When Servicing NGVs

CNG Vehicle ▪ NHTSA FMVSS 304 requires CNG cylinder inspection
Inspection o Every three years/36,000 miles
Requirements o After any fire on the vehicle
o After any vehicle accident
▪ Expired CNG cylinders must be removed
▪ Industry best practice recommends CNG fuel system inspection

General Safety ▪ Leak check all vehicles prior to bringing into maintenance facility
Practices ▪ NEVER bring a leaking vehicle inside a maintenance facility
▪ Close CNG cylinder valves or fuel system isolation valve

Natural Gas Leak ▪ Hand-held electronic gas detector
Detection ▪ Leak detection solution

Signs of a Leak The major signs of a leak on a natural gas vehicle are:
▪ Hearing a hissing sound
▪ Smelling the odor of natural gas
▪ Observing ice formations around a leak point

If you Detect a Leak ▪ Leave the vehicle outdoors
▪ Shut off the cylinder valves
▪ Locate the source of the leak using methane detector and leak check solution
▪ Depressurize that portion of the system
▪ Repair the leak according to manufacturer’s procedures

Safety Practices to ▪ Know whether the component or section of the system is high or low pressure
Address Pressure ▪ Never put a wrench on a pressurized fitting

▪ Turn off gas supply to appropriate section of the fuel system
▪ Depressurize the work area and/or defuel the fuel system

Safety Practices for ▪ Use welding blanket to protect CNG fuel system components
Welding and Hot
Work

NGV Essentials and Safety Practices © 2019 NGVi All Rights Reserved Page 4-2