Gas impermeable tube joint and method of forming same

Abstract

A method of forming a gas impermeable joint in a fluid system includes: providing a tube having a metallic barrier layer disposed between an inner plastic layer and an outer plastic layer; forcing at least one of the inner plastic layer and the outer plastic layer into contact with a plastic surface of a component; and welding the at least one of the inner plastic layer and the outer plastic layer with the plastic surface to form the gas impermeable joint. The welding may include: spin welding, hot plate welding, vibration welding, and ultrasonic welding. The metallic barrier layer extends substantially to the component, thus improving the gas impermeability of the joint between the tube and the component.

Description

BACKGROUND [0001] This invention relates to the joining of tubes to other components in fluid systems. More specifically, this invention relates to gas impermeable tube joints and methods for forming gas impermeable tube joints in fluid systems. [0002] In general, fluid systems serve to contain a fluid (e.g., a liquid, vapor, gas) as it is transported from one location to another. Fluid systems typically include a number of components interconnected by one or more tubes, which transport the fluid between the components. The components and tubes are connected together by joints, which allow the fluid to flow between the components and tubes while preventing leakage of the fluid from the system. [0003] For certain fluid systems, it is important to prevent the infiltration or escape of the fluid in its gaseous state. One such fluid system, for example, is a fuel fill system in a motor vehicle, through which fuel is delivered to a storage tank. The escape of fuel vapor from fuel fill sy...

AI Technical Summary

Benefits of technology

"The patent describes a method for creating a gas impermeable joint in a fluid system by using a tube with a metallic barrier layer and plastic layers. The plastic layers are forced into contact with a plastic surface of a component and welded together to form the joint. The method can be used with different types of plastic welding techniques. The thickness of the plastic layers before welding should be at least 0.6 millimeters, preferably greater than 1 millimeter. The technical effect of this invention is the creation of a reliable and effective gas impermeable joint in a fluid system."

Problems solved by technology

The escape of fuel vapor from fuel fill systems can be hazardous to the environment, and as a result, the U.S. Environmental Protection Agency prescribes limits to the amount of fuel vapor that may escape from the filler pipe.

A significant problem with such hoses is that they are subject to gas infiltration and exfiltration.

Oxygen is particularly troublesome because it is able to penetrate all known plastic films, at least to some small degree.

Once oxygen has gained entry to such a heating system, it deteriorates the hoses and corrodes the pumping system.

Problematically, this method may allow for the permeation of gas through the joint connection.

If the tube has a metallic layer, the permeation may be worse because of the relative inflexibility of the tube material and the resulting inability of the tube to form a tight fit with the projection.

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