The fueling connection devices of compressed natural gas vehicles (NGV), as specified by CSA/ANSI NGV 1-2022: Compressed natural gas vehicle (NGV) fueling connection devices, include the receptacle, protective cap, nozzle, and valve(s). As it serves as the conduit through which compressed natural gas (CNG) passes from the fueling station (where the methane is compressed and stored) to the vehicle (which uses the pressurized resource as fuel), fuel connection devices, on both the vehicle and fuel dispenser system, must be able to handle CNG at its anticipated pressure.
What Are the Applicable Service Pressures of CNG?
In general, CNG retains less than 1 percent of the volume it would occupy at standard atmospheric pressure, but the fuel is kept in tanks of varying pressures at 6,205 kPa (900 psi), 16,500 kPa (2,400 psi), 20,700 kPa (3,000 psi), and 24,800 kPa (3,600 psi), making it essential for the fueling connection devices to follow the same design patterns for harmonized safety and reliability. According to CSA/ANSI NGV 1-2022, the devices designed with these service pressures are to be referred to as:
- “P9” – 6,205 kPa (900 psi)
- “P24” – 16,500 kPa (2,400 psi)
- “P30” and “P30HD” – 20,700 kPa (3,000 psi)
- “P36” and “P36HD” – 24,800 kPa (3,600 psi)
What Are the Types of Compressed NGV Fueling Nozzles?
The fueling nozzle—the device that permits quick connection and disconnection of the fuel supply hose to the receptacle (device permitting safe transfer of fuel) in a safe manner—can be designated according to its use and design. These classifications are listed and detailed in CSA/ANSI NGV 1-2022:
Type 1: For use with dispensing hoses that may remain fully pressurized at dispenser shutdown. This nozzle makes use of an integral valve (or valves) that stops the supply of gas and safely vents the trapped gas before allowing the disconnection of the nozzle from the receptacle. Due to the safe ventilation of the gas prior to disconnection, this type is primarily intended to be used at public fill stations.
Type 2: For use with dispensing hoses that remain fully pressurized at dispenser shutdown. This type makes use of a three-way valve connected to the inlet of the nozzle, which safely vents trapped gas prior to nozzle disconnection. The vent valve operating system is external to the nozzle, and this type is meant to be used by trained operators only.
Type 3: This nozzle is used with dispensing hoses that are automatically depressurized at dispenser shutdown, and it is intended for trained operators only.
Class A: this class specifies high frequency use with a cycle life of 100,000 cycles.
Class B: this class specifies low frequency use with a cycle life of 20,000 cycles.
What Is CSA/ANSI NGV 1-2022?
CSA/ANSI NGV 1-2022 specifies newly-produced compressed natural gas vehicle fueling connection devices, particularly those within the aforementioned service pressures that control NGV fueling in a safe manner. The standard covers background information and construction and assembly guidelines, as well as performance testing for receptacles, fueling nozzles, and Type 2 three-way valves.
Components used in systems designed with its guidelines should be designed for use with gas complying with SAE J 1616-2017: Recommended Practice for Compressed Natural Gas Vehicle Fuel, or an equivalent national standard.
Changes to CSA/ANSI NGV 1-2022
CSA/ANSI NGV 1-2022 was prepared by the NGV 1 Technical SubCommittee on Standards for Natural Gas Fueling Vehicle Receptacle and Fueling Connection Devices. It revises the 2017 edition of the same National Standard of Canada and American National Standard. It underwent the following changes:
- HD profiles and a new low-pressure profile for adsorbed natural gas (ANG) were added.
- As requested by ANG stakeholders, the low pressure profile was changed from P12 (8,300 kPa) to P9 (6,205 kPa).
- The room temperature leak test now only requires type 3 nozzles to be tested at 5 psi.
CSA/ANSI NGV 1-2022: Compressed natural gas vehicle (NGV) fueling connection devices is available on the ANSI Webstore.