By Automotive Online on September 8, 2008 6:08 AM

 
The design of exhaust pipes entails careful planning so as to ensure that toxic and unwanted gases are carried away from the automobile and its occupants. Further, since exhaust gases are extremely hot, the exhaust pipes must be made of materials that can withstand high temperature and are not damaged even when subjected to extreme conditions for hours at a stretch.

Exhaust systems are different for different kinds of automobiles. For instance, in motorcycles, most of the exhaust system is visible. Often when used in trucks the exhaust system is visible too and the muffler is encased in a by a perforated metal sheath to prevent people getting burnt by touching the hot silencer.

Automobile Exhaust System Components

A number of essential components work together to make an exhaust system functional and effective. Explained below are some of these components.

Catalytic Converters

A catalytic converter also known as "catcon" or "cat" is a component used to reduce the toxicity of emissions from an automotive engine. A typical catalytic converter works by creating an environment for a chemical reaction which helps in converting toxic combustion by-products to less-toxic substances. The device was used for the first time in the US in 1975 in order to comply with stricter EPA regulations on auto exhaust emissions. Not only automobiles but catalytic converters are used on generator sets, forklifts, mining equipment and all other machines whose engines emit toxic smoke. Catalytic converters are commonly classified as either Two-way catalytic converters or Three-way catalytic converters. In case of automobiles, catalytic converters are installed for use on flexible fuel vehicles, spark ignition engines (gasoline; liquefied petroleum gas (LPG), compressed natural gas (CNG) engines and compression ignition (diesel) engines.

Exhaust Manifold Gaskets

An essential component of the system, exhaust manifold gaskets seal the exhaust manifold to the cylinder head. Manifold gaskets in automotive exhaust systems interface with an engine to convey exhaust gases away from cylinders of the engine. They are directly mounted to a cylinder head of the engine and receive the exhaust gases, just as the exhaust gases exit the cylinder head. In addition to this primary function, the gaskets prevent exhaust gases from escaping within the engine, which could cause heat damage to components in the engine compartment, create noise, or harm the environment.

Exhaust Pipes

Exhaust pipe assemblies are meant for receiving hot gases from such heat source (i.e. the engine) and convey the hot gases from the heat source toward a lower temperature environment. A typical manifold pipe assembly consists of a manifold     pipe that defines a gas path for conveying hot gases from an inlet end at the engine to the outlet end.

Exhaust Clamps and Brackets

An exhaust system by virtue of its position and function is subjected to extreme temperature and pressure. Exhaust clamps and brackets consist of a hanger for exhaust system components wherein looped and reinforced resilient sheet material is placed between the exhaust system and the vehicle, in addition to the overlapping brackets from the exhaust system. In the event of a failure of the compressed loop, the brackets come into play to provide support to the exhaust system, thus preventing a complete failure.

Exhaust System Components - Buying Tips

You can ensure quality automotive part supplies through the following buying tips.

1. Always prefer new auto parts instead of used ones.

2. Choose your suppliers carefully, establish a reasonable level of trust towards a supplier, through referrals, testimonial, or certifications.

3. Be wary of suppliers offering products at extraordinarily low prices.

4. Ensure the specifics of the products you require from the supplier, before placing the order, a sample inspection is often the best way to do it.

5. You need to understand the terms and conditions including warranties and guarantees associated with the supplies you order.

Industry Overview

Exhaust system has come a long way and today it is expected to meet stricter than ever exhaust gas emission legislations. Furthermore, as the number of custom and sport utility vehicles (SUV) on the roads have increased so has the demand for sophisticated exhaust systems. This is even more relevant with respect to the performance equipment aftermarket, such as in the US.

Exhaust emissions, as already mentioned have become the top consideration in the  development and manufacture of exhaust system and the automotive trade associations need to take a note of the changing scenario. The issue of exhaust emissions has caught the limelight mostly due to the widespread environmental awareness and consciousness that pollution from automobiles causes many of today’s health problems. At the same time the emission regulation has led to the manufacture of more technologically complex and expensive exhaust treatment components for installation within automobiles.

Trends suggest that state-of-the-art exhaust systems will entail developing filters that would trap most of the environmentally harmful emission content. Designing mufflers for increasingly silent exhaust systems is another important area.

While catalytic converters make up for a critical components assisting in compliance with emission legislation, new technologies such as fuel cell technology may eat into the market for catalytic converters. Nevertheless, substrates and catalytically active coating will still be needed.