AUSTRALIA SINGAPORE
Process Flow Diagram
A process flow diagram (PFD) provides a high-level overview of an industrial process, illustrating the sequence of operations, material flows, and major equipment. Commonly used in chemical, energy, resources, and water industries, it serves as a conceptual blueprint for process design, feasibility studies, and plant operations. PFDs outline key equipment such as reactors, distillation columns, pumps, and storage tanks, connected by material and energy flow lines. They also show flow direction and may include basic process parameters like temperature and pressure. However, they do not detail piping, instrumentation, or control logic. These are covered in piping & instrumentation diagrams (P&IDs). Used by engineers, project teams, and plant operators, PFDs help optimise processes, improve efficiency, and ensure regulatory compliance. By providing a clear roadmap of material movement and process interactions, they support the transition from conceptual design to detailed engineering and implementation.
PROCESS ENGINEERING CONSULTANTS
When designing a chemical plant, our process engineering consultants take a structured approach to ensure efficiency, safety, and compliance. Through our process engineering services, we begin by defining project objectives, evaluating technological options, and establishing the design basis. Next, we develop process flow diagrams (PFDs) to map out material flows, key equipment, and overall plant operations, providing a clear visual representation of how raw materials are transformed into final products. We then refine the design with piping and instrumentation diagrams (P&IDs), detailing control strategies, system interconnections, and instrumentation requirements to ensure seamless and reliable plant operation.
With the P&IDs in place, our process engineers work closely with control engineers to develop the control philosophy and functional specifications. This collaboration helps define control strategies, interlocks, alarms, and system responses to various operating conditions, ultimately enhancing process efficiency, safety, and reliability. To ensure reliable and efficient plant performance, we carefully size and specify all equipment, considering factors such as process demands, energy efficiency, and safety requirements. Proper equipment selection minimises operational risks and ensures long-term sustainability and cost-effectiveness.
Safety is a top priority, so we conduct hazard and operability studies (HAZOP) to identify and address potential risks. Finally, we ensure the design meets industry standards and environmental regulations, delivering solutions that are both technically sound and compliant. With our process engineering services, we provide clients with efficient, cost-effective, and sustainable solutions, ensuring seamless project execution from concept to completion.
What is Process Engineering Design?
Chemical and Process Engineering
The chemical manufacturing processes have involved from modest to complex production of chemicals converting raw materials such as fossil fuels, water, minerals, metals, and others to become thousands of products central to our everyday modern living. Chemical and process engineering deals with the development, design, operation, and management of converting these raw materials safely and cost- effectively. It is founded on the principles of chemistry, physics, and mathematics. The laws of physical chemistry and physics govern the practicability and efficiency of chemical engineering operations, whilst mathematics aids the essential tool in optimisation and modelling.
Chemical Process Engineering in Design
The design of a process plant starts with an idea to produce a new product or improve an existing one. It is usually a result of one or more chemical reactions and mainly the physical processes such as the separation of the components or a group of components from a natural mixture, are the subject of the design. An excellent example of such a process is crude oil primary separation.
The engineering design of a chemical manufacturing process can be categorised into two broad phases.
The conceptual or process design is the first phase that includes the selection of the chemical process, technology, process conditions, collection of required data, issuing of process flowsheets, selection, specification, and chemical engineering calculations of equipment, and preliminary cost estimation. Typically, in a project organisation, the process engineering design team is heavily involved in this phase also known as the front-end engineering design (FEED).
The second phase, basic plant design, includes the detailed mechanical design of equipment, detailed design of electrical systems, civil structures, piping and ancillary services. The support design group is responsible for these engineering activities as they have the expertise in other engineering disciplines required to complete the plant design.
A typical chemical process plant design can be illustrated in these phases, as shown below.
The different phases of the project as shown above illustrates that the goal of plant design is to complete them within the framework of projects. The process engineers are heavily involved in FEED within this project phase and constantly interact and communicate with other engineering disciplines.
Process Engineering Key Role
Establishing the steps in a chemical plant design is essential and recognises the involvement of the multidiscipline engineering. Since process engineering design is conducted at the front-end of plant engineering design, therefore, outputs or deliverables from this stage have a significant impact on the subsequent design stages. The non-exhaustive list of process engineering workflow is illustrated below.
Seamless collaboration among different engineering disciplines is key to a successful chemical plant design execution. With this tight collaboration with other engineering disciplines, process engineers set work priorities, choose equipment, select instrument from alternatives, identify key hydraulic and elevation constraints. Aligning process engineering activities as well as deliverables sets the groundwork for the whole design execution and strategy.
The process information flow is communicated through the activities and deliverables that the process engineering owns or shares with another engineering discipline. One deliverable example is the piping and instrumentation diagram (P&ID). The P&ID is a schematic representation used to facilitate the design process, convey intent, or construct and communicate information to the client and all involved disciplines.
Process Plant Consultants
Large-scale organisations may utilise their own design teams to conduct the entire project design and even execute the plant construction, all within their organisation. However, most commercial-scale process plants are very complex, consisted of various unit operations linked together by piping and automatically controlled via basic process control system (BPCS). Many process engineers working in a process plant are operations engineers specifically trained to troubleshoot an underperforming- or optimise a chemical plant but may lack the skills and experience to design a chemical plant.
To minimise risks, organisations of many sizes usually outsource and commission a process plant consultant also known as engineering, procurement and construction management (EPCM) to design the process plant. The process engineers can be part of either the EPCM’s organisation or the owner's engineering design team. Process engineers in the EPCM’s organisation are part of the project team executing the design and performing the deliverables in the project. The process engineers that are part of the owner's design and engineering team are the engineering consultants responsible for reviewing and approving the deliverables from the contracted EPCM organisation to ensure that the deliverables comply with the design specifications and requirements.
Piping & Instrumentation Diagram
A piping & instrumentation diagram (P&ID) is a detailed engineering drawing that illustrates the interconnections between process equipment, piping, instrumentation, and control systems in an industrial plant. It serves as a critical reference for process engineers, control engineers, operators, and maintenance teams, ensuring smooth plant operation and safety.
Unlike PFD, which provides a high-level view of a process, a P&ID contains precise technical details necessary for plant construction, operation, and maintenance. It includes piping routes, valves, pumps, pressure and temperature indicators, flow meters, control loops, and safety devices. The diagram also highlights automation components such as sensors, alarms, interlocks, and shutdown mechanisms, ensuring process control and safety compliance.
P&IDs play a vital role in process control philosophy by defining how different control systems interact to maintain stable operations. They serve as a roadmap for plant automation, helping control engineers develop functional specifications, logic diagrams, and distributed control system (DCS) programming. During the hazard and operability (HAZOP) study, P&IDs are used to identify potential risks and develop mitigation strategies.
In addition to design and operational planning, P&IDs assist in troubleshooting and maintenance, enabling engineers to quickly locate equipment, control valves, and instrumentation for diagnostics and repairs. They also serve as key documentation for regulatory compliance, ensuring that safety and environmental standards are met.
Overall, a P&ID is a foundational document in process engineering, providing a comprehensive representation of a plant’s mechanical and control systems. It ensures seamless integration between process design, automation, and safety, making it indispensable for engineering, construction, and operations teams.