Correct design and layout of the SCR BYPASS SYSTEM is critically important to the efficiency and operation of power plants. Utilities have even had to consider closing down plants that could not efficiently operate their Bypass Systems. Numerous gas path configurations are available, which vary considerably based on site and space limitations, construction lifting capabilities and site construction limitations, as well as other key considerations specific to each plant site. This technical paper discusses a number of arrangements, technical selection and layout criteria. This paper discusses case studies and design details of approximately 20,000 MW of successful bypass system equipment which improve system performance, reduce pressure drop, reduce abrasive wear, substantially minimize maintenance costs and simplify operating requirements.