A Process Flow Diagram (PFD) is a diagram commonly used in chemical and process engineering to indicate the general flow of plant processes and equipment. The PFD displays the relationship between major equipment of a plant facility and does not show minor details like piping or designation. Typically, process flow diagrams of a single unit process include process piping, major equipment, connections with other systems, major bypass and recirculation streams, and operational data. One of the easiest examples to understand PFD is to learn how Asphalt production happens in a factory. Asphalt is produced through the refining of petroleum. The following PFD is built using EdrawMax software and shows YSG Type Modified Asphalt Production Process Flow Diagram shows several types of equipment like expansion tank, pre-shearing machine, stabilizer absorption system, modifier absorption system, asphalt discharge pump, and Level 3 High-speed shearing machine.