The spark plug is essentially a device that generates an electric spark to ignite the compressed air-fuel mixture inside the engine cylinder. This ignition process creates a small explosion, which pushes the piston down and ultimately drives the vehicle forward. Without spark plugs, the engine would not be able to start or run efficiently.

This tough, chemically inert polymer has a wide working scope as well as: 

Choosing the correct oil seal application

Oil seals are made out of nitrile synthetic rubber with steel stiffener rings. Other rubbers such as viton, silicon, neoprene or poly acrylic can be used for specific applications. The stiffener rings may be stainless steel or brass where highly corrosive fluids are to be sealed. Springs are generally made of spring steel to IS: 4454:Gr.ll or from stainless steel or bronze for corrosion resistance

3. Seal types and numbering system

Figure 2: Typically shaped oil seal and component nomenclature

No single physical property of rubbers is responsible for the successful performance of an oil seal or ‘O’ ring. The ultimate tensile strength, breaking elongation, modulus, shore hardness, creep and stress relaxation in tension and compression loads are all important physical properties that characterize a seal or ‘O’ ring. Compression strength and set together with stress relaxation or decay are important for effective sealing. The difference in these properties in a swollen seal is highly critical. An optimum swelling value in a fluid medium is a desirable feature. De-swelling decreases the seal pressure against the wall of the housing where the seal is fixed, leading to leakage. Over swelling minimizes the physical properties of the rubber. Seals made of polysulfide rubbers have extreme fuel resistance but undesirably high compression set. The effect of temperature on the seal is an important factor. Swelling under stress can increase at higher temperatures and a suitable compounding technique should be adopted to reduce this effect.

Table 4: Type of selected seal