This site will work and look better in a browser that supports web standards, but it is accessible to any browser or Internet device.

Idaho National Laboratory

Natural Gas Technologies
Improved and Standardized LNG Receptacles and Nozzles

The INL liquefied natural gas research team is working with LNG industry groups and with the U.S. Department of Energy in the early stages of an effort to standardize the receptacles used with vehicle fuel tanks and the nozzles used at LNG refueling stations. The use of LNG as a vehicle fuel presents technological challenges at the filling station different from those associated with conventional fuels. LNG is a cryogenic liquid stored and transferred under pressure, with temperatures typically ranging from -260 to -200F and pressures ranging from 25 to 250 psi.

In current use, the end of the hose at an LNG filling station is equipped with a special nozzle that mates with a special receptacle on the spout of the vehicle's fuel tank. The assembly includes some means to lock the nozzle to the receptacle for a hopefully leak-tight fit during filling, then unlock for removal of the nozzle with minimum fuel spillage and minimum risk of leakage from either the nozzle or the receptacle.

As the use of LNG in vehicles increases, the need to improve and standardize the associated nozzles and receptacles becomes more urgent. Currently at least three different nozzle/receptacle designs are commercially available: Parker, C.J. Carter (Formerly MOOG), and MVE. Each has advantages and disadvantages, strengths and weaknesses. None is ideal. None is compatible with either of the other two (that is, for example, the Parker nozzle will not mate with the Carter receptacle). The need for standardization lies in the eventual impracticability of having several incompatible configurations in use in the commercial sector.

At present, use of LNG in the field is limited mostly to demonstration vehicles that are part of larger fleets, with the LNG vehicles being refueled at their own home filling station. Upon entering the LNG market, the fleet owner selects one of the available configurations and equips the fleet's vehicles and filling station accordingly. This arrangement, though not ideal, is workable at that level of use, and is typical of an industry in its infant stage. However, as LNG use becomes more widespread to include private vehicles and travel far from the home filling station, the lack of standardization becomes an obstacle.

We look forward to the day when private and commercial LNG-powered vehicles operate and refuel with the same ease and convenience as gasoline- and diesel-powered vehicles do now. That will not happen until nozzles and receptacles are improved and standardized, so that drivers and attendants with minimal training can safely and easily refuel any LNG vehicle at any LNG filling station without the use of special protective clothing or equipment.

Performance requirements are of two types, the first type relating to design improvements and the second type relating to standardization for compatibility of nozzles and receptacles.

Design improvements would produce the following outcomes:

The research and collaboration efforts would focus on the design improvements listed above, with standardization (compatibility) as a secondary goal. The standardization effort would consider several possible outcomes, including:

The earlier the design is standardized, the less the existing manufacturers and customers have invested in the current designs, and the smaller the impact on the population of LNG vehicles and filling stations already in the field. (After standardization, older vehicles and filling stations will need to be either retrofitted or equipped with adapters). In the present situation, existing manufacturers have an interest in capturing the largest possible market share in competition with the other manufacturers, yet the market is too small for them to justify investing large amounts of private sector money in design improvement research. The standardization effort will be most successful if all the current manufacturers perceive that their best interest lies in participating in the collaboration.

Business Contact:
David Anderson, (208) 526-0837, Send E-mail
Technical Contacts:
Program and Technical Manager: Bruce Wilding, (208) 526-8160, Send E-mail