1. Scope--Compressed Natural Gas (CNG) is a practical automotive fuel, with advantages and disadvantages when compared to gasoline. It has a good octane quality, is clean burning, easy to meter, and generally produces lower vehicle exhaust emissions. CNG is used to fuel internal combustion engines. Natural gas is normally compressed form 20 690 to 24 820 kPa (3000 to 3600 psig) to increase its energy density thereby reducing its on-board vehicle storage volume for a given range and payload.

The properties of natural gas are influenced by (1) the processing of natural gas by the production and transmission companies and (2) the regional gas supply, storage, and demand balancing done by distribution companies often in concert with pipeline companies to maintain uninterrupted service throughout the year, e.g., peakshaving with propane-air (see U.S. Bureau of Mines Publication 503).

Information on the properties of distribution system natural gas and its variability has been included in Figure 1 and can be found in GRI-92/0123. The analysis in this reference summarizes the expected composition of natural gas in 26 cities. Composition can vary hourly under certain operating conditions in certain areas of the country. Thus the data should generally be considered representative for the areas mentioned with due consideration for local variation.

Natural gas is comprised chiefly of methane (generally 88 to 96 mole percent) with the balance being a decreasing proportion of non-methane alkanes (i.e., ethane, propane, butanes, etc.).

Other components found in natural gas are nitrogen (N2), carbon dioxide (CO2), water, oxygen, and trace amounts of lubricating oil (from compressors) and sulfur found as hydrogen sulfide (H2S) and other sulfur compounds. Before entering the transmission system, it is processed to meet limits on hydrogen sulfide, water, condensibles of heavier hydrocarbons, inert gases such as carbon dioxide and nitrogen, and energy content. Mercaptan odorants (e.g., tertiary butyl mercaptan) are added by local distribution companies (LDC's) for safety reasons to detect the presence of natural gas which otherwise would be odorless.

Water content and other corrosion precursors, heavier hydrocarbons which may condense within the fuel container, particulate matter, oil and energy content need to be controlled in order to minimize corrosion and provide satisfactory low-temperature vehicle operation, performance, and emissions levels.

The provisions contained in this SAE Recommended Practice are intended to protect the interior surfaces of the fuel container and other vehicle fuel system components such as fuel injector and exhaust catalyst elements from the onset of corrosion, poisoning, the deposition of liquids or large dust particles, or the formation of water, ice particles, frost, or hydrates. The provisions contained in this document are not intended to address the composition of natural gas as delivered to a fueling station, but rather at the outlet of the fueling station as delivered into the containers on the vehicle. Limits on gas composition constituents currently not included in this document may be added when data are available to substantiate them.

1.1 Purpose--This document presents the more important physical and chemical characteristics of compressed natural gas vehicle fuel and describes pertinent test methods for defining or evaluating these properties.

In order for compressed Natural Gas Vehicles (NGVs) to effectively provide satisfactory and safe operation for users, there is a need to address specific issues relative to the use of natural gas as a vehicle fuel. The two primary areas relate to (1) compressed storage of natural gas and (2) vehicle fuel system and engine performance issues. These provisions have been derived through a joint effort of the SAE TC-7 Natural Gas Vehicle Task Force and the Technology Committee of the Natural Gas Vehicle Coalition.

NOTE--This document is intended as a guide and is subject to change to keep pace with experience and technical advances. The following are separate documents that are not part of the document, but are added as an Informative Appendix (Appendix A).

Background Statement--Summarizes the development of the maximum water content provision for SAE J1616. Excerpts from ANSI AGA/NGV2--Basic Requirements for Compressed Natural Gas Vehicle Fuel Containers Bibliography of SAE Publications and Other Publications.

Rationale Document for SAE J1616.

Customers who purchased SAE J1616
also purchased

• ASME PTC 10 : Performance Test Code on Compressors and Exhausters
• AAMI TIR33 : Sterilization of health care products - Radiation - Substantiation of a selected sterilization dose - Method VDmax

See More Documents