Joint and flange assemblies are used in many different fields, such as within the automotive industry to connect automotive exhaust pipes together to form exhaust systems. FIG. 1 is an isometric view illustration of a flange assembly 10, in accordance with the prior art. FIG. 2 is a cross-sectional view illustration of a flange assembly 10, in accordance with the prior art. With reference to FIGS. 1-2, the flange assembly 10 includes two flanges 12, 14, which are engaged together with a fastener 16, such as a bolt and nut. Two lengths of exhaust pipe 20, 22 or tube are connected together using the flange assembly 10. For example, exhaust pipe 20 is welded or otherwise affixed to one flange 12, whereas exhaust pipe 22 is welded or otherwise affixed to the other flange 14. The flange assembly 10 keeps the exhaust pipes 20, 22 in contact together, thereby allowing exhaust gases to move through the exhaust pipes 20, 22 and out of the exhaust system.
These conventional exhaust flanges have many shortcomings. For one, the cost to manufacture automotive exhaust flanges is increasingly becoming a critical factor in the manufacture of car parts. Manufacturers are striving to reduce their costs by reducing the labor or material expenses associated with manufacturing the flanges. Another shortcoming that manufacturers face is the ability to manufacture products that are able to meet required emission standards over a predetermined period of time, such as during a warrantee period of a car. As a result, individual parts within the exhaust system, such as exhaust flanges, must be manufactured to ensure full operation during the warranty period, which can be a very difficult task.
Another problem faced by manufacturers of exhaust flanges is damage of the products due to corrosion, such as due to external corrosion from the elements. For example, flanges are in almost constant exposure to the elements, including high heat followed by moisture, water, snow, and/or ice quenching in high saline conditions. Most conventional exhaust flanges are manufactured entirely using standard carbon steel or stainless steel, but both of these materials have inherent disadvantages. Stainless steel exhaust flanges have adequate corrosion resistance but are costly to produce and therefore, the cost of replacing stainless steel exhaust flanges is relatively high. On the other hand, carbon steel exhaust flanges are cost-effective but typically corrode quickly and, as a result, are difficult to service within the warranty period.
Exhaust flanges can also be damaged by the exhaust gases themselves which can cause the flanges to bind and corrode, which makes the flange or the exhaust system difficult to service. For example, the fasteners used to connect flanges may be subject to long periods of exhaust gas exposure, which causes a build-up of foreign materials on the threads of the fasteners and makes them difficult to remove. As a result, service to exhaust systems involving disassembly can often require cutting of the exhaust pipes and in some cases necessitate unnecessary replacement of catalytic converters and/or mufflers.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.