Page 20 - CNG ESP Participant Guide2024

Module 2: High-Pressure CNG Fuel System Components

Lesson 2.1: Types of CNG Systems

Comparing Characteristic Dedicated Bi-Fuel Dual-Fuel
Dedicated, Bi-Fuel Operates on what Natural gas Natural gas or Diesel and Natural gas
and Dual-Fuel NGVs fuel(s)? gasoline
Operates on how 1 – Natural gas 1 – Natural gas 2 – Diesel and natural
many fuels or gasoline gas
simultaneously?
Typical Vehicle ▪ Light-Duty ▪ Light-Duty ▪ Heavy-Duty
Classes ▪ Medium-Duty ▪ Medium-Duty
▪ Heavy-Duty
Number of fuel 1 – Natural gas 2 – Natural gas 2 – Diesel and natural
systems onboard and gasoline gas
Ignition Source Spark plug Spark plug Diesel combustion
Engine ▪ Higher ▪ Hardened ▪ Fuel management
Modifications compression valves and system
▪ Unique spark valve seats ▪ No spark plugs
plugs ▪ Unique spark
plugs

Typical CNG Fuel
System

APG Dual-Fuel
System

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