In the previous article, we discussed the first phase: “Technology/Contractor Selection” and the steps that are usually performed in this phase. This article will discuss the second phase “Engineering & Procurement”.
PHASE II: Engineering & Procurement
After the project is awarded to the successful contractor, the contractor and the client kick off the industrial plant project, which involves two major engineering stages performed in sequence with some parallel activities. They are basic engineering design and detailed engineering design.
Basic Engineering Design (BED)
The purpose of this phase is to define the basic processing conditions of the plant, equipment and piping lay out, equipment sizing, operational requirements, etc. Mainly developed using software systems, it also fixes the process flow diagrams (PFDs), heat and material balances, and the utility consumptions.
The process design during BED is based on further details involving specific codes, standards, project specifications, etc. A major part at this stage is the completion of equipment data sheets and the piping and instrumentation diagrams (P&IDs), forming the foundation of the detailed mechanical design. All these activities are linked to hazard, reliability, and operability studies (HAZOP), which mainly focuses on the safety, constructability, operations and maintenance aspects.
Detailed Engineering Design (DED)
The DED is the most extensive design stage of the entire project, and all mechanical definitions are finalized in this stage. A major part of this design is associated with the design layout and stress analysis of all piping systems, and detailed definition and orientation of all plant equipment.
Apart from the above basic engineering, the contractor needs immense and specific knowledge of detailed engineering, which includes engineering and drafting activities associated with design. Using 3D-CAD and modeling systems, precise sizing and orientation of the equipment nozzles, etc., can be done. The release of design documentation for construction will take place only after HAZOP studies are conducted so that the design meets all requirements of safety, operability, maintainability, etc.
Procurement Starts During Engineering Stage
During basic engineering, long lead-time equipment such as major process compressors/turbines, major towers, etc., may be procured as they usually form the key components in the critical path of the industrial plant project schedule. It should be noted that the preparation of procurement papers and the time to manufacture the components for the major process compressors, turbines, and fractionation columns is a time-consuming process. Hence, major efforts are required to finalize the design basis of this equipment so that they can be procured early during the engineering phase. After establishing this clear design basis, during the detailed design, the procurement of required equipment should proceed.
For smooth and successful construction, it is essential to plan and facilitate an unhindered supply of construction material through timely procurement, i.e., as per the construction plan.
As the project progresses in DED, construction bid packages are prepared and issued to qualified construction contractors. The contractors receive the packages and submit technical and commercial proposals to the client after deliberations on job implementation. The submitted proposals are evaluated and an award recommendation is developed by the contractor, in order to allow the client to make a final selection.
Other major activities in the engineering phase are:
HAZOP reviews
Inclusion of safety- and hazard-related issues in the engineering phase incorporates the safety requirements into the project. It also helps to define the final estimate of the plant cost and determine the remedial measures that may be required to meet the project safety standards. HAZOP reviews include the health, safety and environmental issues in the engineering processes and define a rough cost estimate to address them. The HAZOP stages are usually conducted with participation of key people—from the contractor’s staff as well as the client’s operating and maintenance staff—to jointly identify and evaluate the hazards in terms of health, safety, and environmental issues at the timely stages of the project.
Model review
This is an action in which the contractor usually models the plant for the client to review from different aspects such as safety, constructability, accessibility, and maintainability. The review and subsequent feedback by the client should be incorporated into the model for implementation and include necessary modifications.
Hydraulics study
Hydraulic studies must be conducted by the contractor in order to generate isometric drawings based on final piping lay out. Hydraulic studies will be conducted on industrial plant piping for sizing of process and utilities piping to facilitate the issuance of purchase enquiries for bulk piping materials.
Utility balances
Utility balances for cooling water, BFW and steam, power, air and nitrogen, etc., for different design cases have to be generated by the contactor. The main purpose of this is to ensure that all utility requirements for various design cases for different operation modes are met.
Safety studies
Safety studies of the plant, especially in dealing with highly volatile feedstock and final products, are crucial. Safety studies are essential because of vulnerability of the plant to hazards. Occurrence of any incident can affect the environment as well as plant personnel, and must be avoided. The aim of these studies is to finalize consequence modeling for hydrocarbon release in the industrial plant, to finalize fire protection measures such as deluge system, fireproofing, etc. Safety relief valve calculations and flare loading summaries can also be finalized through these studies.
Operating procedures
Based on the plant design, the operating procedures of plant units and systems are usually generated by the contractor in consultation with the client/owner. Emergencies and off-design scenarios for various process systems should be envisioned, and the required procedures should be made available to the client. The procedures for start up, commissioning, and for both normal and emergency shutdowns are to be developed by the contractor as well.
Maintenance procedures & capital spare parts
Contractor and equipment vendors often jointly develop the equipment maintenance procedures and hand them over to the client. Both vendors and contractor will also develop and furnish the scope for the procurement of the recommended capital spare parts and special maintenance tools of the critical equipment in the industrial plant.
In the next part of this series, we will discuss the third phase of the industrial project “PHASE III: Construction and Turnover”.
