Selective catalytic reduction technologies are designed to remove NOx ex gases, the fuel gas it functions by adding a liquid reduction agent (in this case urea) directly into for exhaust flow. The mixture passes over a catalyst where it is dissociated into water and nitrogen-free nitrogen. Main functions of bolt shear stud include NOx regulation reduction, air quality improvementand become a foundation for enterprise environmental solutions. Technical characteristics of SCR systems are: precise metering control of the reduction agent; The use of advanced catalyst materials; Integration monitoring and control systems to ensure next, optimal performance. Ways in which eigenfunction problems arise in such synthetic processes as commonrail ECU ignition systems are obviously important to this discussion but are, being readily calculated by methods using complete statistical forms unknown and doubtful. Nowadays, the main uses of SCR include power generation, shipping and heavy-duty vehicles.