Process plants require numerous types of equipment to produce the required products from the feed or raw material. This may involve moving gases, liquids and sometimes solids, and carrying out reaction, distillation or separation, cooling, heating and storage of feed, products, byproducts and supporting systems. Process equipment may include columns/towers, reactors, pumps, vessels/drums, compressors, furnaces, heat exchangers, gas or steam turbines, etc. Supporting equipment may include tanks, cooling towers, water treatment equipment, boilers, chemical storage/handling, fuel systems, air systems, flaring systems, fire protection, wastewater treatment equipment, fire protection equipment, loading/unloading arms, etc. A billion-dollar project can comprise up to 1,000 equipment items.
Process engineers develop schematic drawings that show how fluids move from point A to point B. These drawings will also show associated measurements, monitoring, controls, safety devices, etc. While several names and variations exist for these schematic drawings, this article will refer to them as piping and instrumentation diagrams (P&IDs).
Anyone that has been involved with P&IDs for front-end engineering design (FEED) or engineering, procurement and construction (EPC) projects may be familiar with the subject matter discussed here. However, for any engineer, owner or operator coming from a non-P&ID world to the P&ID world, this article will increase understanding of the subject and lessen the potential daily shocks.