Project Key drawings

Throughout the design stages and phases, the development of certain critical drawings is essential. In the initial stages, these drawings serve as preliminary purpose that explore various options or the envelope of the design. As the design progresses toward its later stages, it becomes necessary to expand, refine, or detail out these drawings for review and approval as a basis for a deliverable from the detailed design phase.

The key documents include the following:

• Block Flow Diagram

  The Block Flow Diagram is the fundamental process outline and is a simplified drawing that illustrates the major process steps or unit operations that is required for the overall process design. This drawing indicates the major feeds (input streams), the process steps to be performed (unit operations), and the resulting products (outputs streams). You can issue the Block Flow Diagram as an independent drawing or incorporate it into the written Process Design Basis for reference.

• Process Flow Diagrams (PFDs)

  These diagrams provide a detailed visual representation of the overall process flow scheme that captures all the required unit operations and their specific order within the complete process system. This drawing is typically used as a reference document for the Heat and Material Balance to provide overall stream data and process conditions for the process including utility streams.

• Material Selection Diagrams (MSDs)

  MSDs represent the same topology and view of the process as the PFDs but include additional details that specify the material specifications verses process data for the equipment and piping that are necessary for the project. These specifications consider the client's specific requirements, the corrosion resistance, and the anticipated economic lifespan of the plant.

• Piping and Instrumentation Diagrams (P&IDs)

  P&IDs are the most critical documents that depict the necessary process design and the comprehensive range of equipment, instrumentation, and piping that are involved in the project. While they share the process flow scheme shown in the PFDs, P&IDs provide a far more detailed view. P&IDs must include every piece of information necessary to proceed with the detailed design phase, detailing all the components such as equipment, piping, valves, specific fittings, instruments, and safety mechanisms needed to build a fully functional, safe, and operational process plant.

• Site Plan (or Plot Plan)

  The Site Plan illustrates the comprehensive arrangement of the new process unit within the context of the larger facility, showcasing the relationship with essential infrastructure and access points such as roads, railways, and water management systems. Additionally, this plan delineates the provision of critical utilities such as cooling water, service water, and various types of air supplies, particularly when these utilities must be sourced from beyond the designated area of the new unit's operations. For very early estimates, the Site Plan may be used to estimate one of the largest variables, such as the approximate length of a pipe.

• General Arrangement (GA) Drawings

  GA Drawings provide a visual representation of the spatial arrangement of equipment within the designated limits of the process unit. These drawings detail the physical dimensions and placement of all equipment, as well as the layout of significant buildings and structures. GA Drawings serve a critical function in assessing potential issues related to accessibility for safety, operation, maintenance, and the feasibility of construction.

• Piping One-Line Drawings

  Piping One-Line Drawings offer a simplified one-line illustration of the primary pipe runs that are necessary for the project. For ease of understanding, these diagrams are often produced against the GA Drawings and Site Plan. In terms of the project cost estimate, one of the most significant factors is layout and therefore the length of pipe together with major support structures and pipe racks. Here, the Piping One-Line Drawings material take-offs are key.

• Electrical One-Line Drawings

  Electrical One-Line Drawings display a consolidated view of the necessary electrical connections for the project. These diagrams simplify the complexity of electrical systems into single-line representations, showing the power loads and supplies to all electrical motors and including all critical electrical components such as main power lines, generators, transformers, switches, contactors, and motor control centers (MCCs).