Process Engineering Scope of Work in Petrochemical Plants

1  Scope

1.1    The scope of the process engineering work to be performed by the ENGINEERING CONTRACTOR will depend upon the project execution strategy developed by Company. Details of this strategy as related to process engineering work will be given in the contract scope. In general, the process engineering work will be associated with one, or both, of the following categories:

• Basic conceptual design of the plant process.
• Detailed process design of the plant.

  

1.2    Basic Conceptual Design of the Plant Process

1.2.1 The ENGINEERING CONTRACTOR with appropriate input from Company shall be responsible for analyzing and selecting the necessary unit process operations to achieve a complete, efficient process cycle to deliver the required product from the plant.

1.2.2 The ENGINEERING CONTRACTOR shall design a process that takes the raw feedstock to the plant, and converts it into the required end product(s) having the necessary pressure, temperature, flow, composition, and purity.

1.2.3 The ENGINEERING CONTRACTOR shall produce at least preliminary process flow diagrams (PFD), preliminary process and instrument diagrams (P&ID), and preliminary heat and material balances (H&M) as part of the conceptual design.

1.3    Detailed Process Design of the Plant

1.3.1 The ENGINEERING CONTRACTOR using the selected unit operations and overall process cycle shall be responsible for doing the necessary detail analyses and calculations to produce the information and data required by the other engineering disciplines to specify, design, purchase, and fabricate all of the equipment, piping, etc. for the plant.

1.3.2 The ENGINEERING CONTRACTOR shall produce the necessary documents such as final PFDs, updated P&ID, final H&M balances, equipment duty datasheets, and related documents, as part of the detailed process design.

1.4    The ENGINEERING CONTRACTOR shall not do the process engineering work for the following:

• Packaged systems that are engineered, designed, and fabricated by third party suppliers.
• Any systems done by Company.

2       Codes, Standards, and Specifications

2.1    The ENGINEERING CONTRACTOR shall follow any general codes, standards, specifications, or requirements listed in the contract scope appendix.

2.2    Documents associated with any project specific process details will be given in the contract scope.

3       Company Deliverables to the Engineering Contractor

3.1    General

3.1.1 This section provides a general description of the typical documents that will be issued by Company to the ENGINEERING CONTRACTOR as the basis for the process engineering work to be done by the EC. The contract scope will state the specifics for the project including any deliverables that are to be added and any deliverables that are to be deleted from the EC’s scope.

3.3.2    In general, the following documents related to process engineering will be issued by Company to the EC.

13.3.2.1 General Project Information – This document will include basic information that applies to the plant site, such as the plant location, dimensions of site, access to site, utilities available, and related information.

3.2.2 Facility Arrangement/Plot Plan – The amount and type information on this drawing will depend upon the specific type of process engineering work to be done (i.e., conceptual vs. detailed). For conceptual work, the drawing would only have very preliminary information such as property lines, rough plant area outline, battery limits, roads, and similar information. For detailed work, the drawing would have the above information, plus at least a general layout and arrangement of the plant equipment, buildings, and major pipe routes. A unit operation key plan may be included where appropriate.

3.2.3 Plant Process Requirements – This document will include a description of the incoming feedstock to the plant. Such conditions as pressure, temperature, flow, composition,

physical state/characteristics, and related information will be stated. The required product(s) to be produced by the plant will be stated. This includes pressure, temperature, flow, composition, minimum purity levels, minimum recoveries/efficiencies, physical state, and any other significant requirements of the product.

3.2.4 Scope Split – For those projects where the entire process engineering work scope is not to be done by the EC, this document will delineate what specific parts of the process engineering work are to be done by the EC, and what parts are to be done by Company, or others. It will include interface information concerning those locations where the different scopes of work meet.

3.2.5 Process Design Methods (PDMs) – When deemed necessary and appropriate by Company, certain Company proprietary PDMs may be provided to the EC. These PDMs contain information that relates to specific data and design techniques developed by Company concerning specific process technologies.

3.2.6 Piping and Instrument Diagram (P&ID) – This document will be provided only when detailed process engineering work is to be done by the EC. This basic P&ID will contain preliminary information about the plant process cycle in schematic form. Information such as piping, valves, instruments, controls, and equipment will be shown. It is anticipated that the ENGINEERING CONTRACTOR will provide some of the detailed information for the P&ID as part of the EC’s detailed scope of work.

4       Deliverables From the Engineering Contractor

4.1    General

4.1.1 This section provides a description of the documents that shall be produced by the EC. The documents shall be issued to Company as the process engineering work is completed. The project contract scope may add to, or reduce, the scope of work and documents that are to be provided by the ENGINEERING CONTRACTOR for a specific project.

4.1.2 The documents that the ENGINEERING CONTRACTOR shall provide will depend upon which of the process engineering work scope(s) are to be done. These scopes are:

• Basic Conceptual Process Design
• Detailed Process Design

4.2    Basic Conceptual Process Design Scope Deliverables

4.2.1 Process Simulations and Calculations – The ENGINEERING CONTRACTOR shall utilize available process simulation software supplemented with manual calculations where necessary to develop the optimum process cycle for the plant. The input and output of these simulations, along with any manual process calculations shall be submitted to Company.

4.2.2 Process Flow Diagrams (PFDs) – The ENGINEERING CONTRACTOR shall develop and submit to Company PFDs for the plant process cycle being utilized. There probably will be multiple PFDs required depending upon the scope of the EC’s process engineering work, and the number of process unit operations being utilized. The PFDs shall include the following information:

• All process equipment with item tag numbers.
• Heat and material balance point numbers (a minimum of one heat and material balance point is required upstream and downstream of each piece of process equipment).
• Basic control strategy showing control valve locations, type, and sensing locations.
• Circuit design pressures.
• Utility use points (e.g., cooling water and steam).
• Major process line sizes.

4.2.3 Heat and Material Balance (H&M) – The ENGINEERING CONTRACTOR shall develop and submit to Company heat and material balance charts for the plant process being utilized. There probably will be multiple operating cases required for the plant, which must be included in these balance(s). The heat and material balances shall include the following information:

• Design case and any alternate operating cases required, listing all balance points designated on the PDF(s).
• Data for all process, steam, and utility streams.
• Description of normal process excursions, specifying cause, temperatures, pressures, and flow rates.
• Guaranteed rates.
• Safe upper and lower limits for temperatures, pressures, and flows.

4.2.4 Piping and Instrument Diagraph (P&ID) – The ENGINEERING CONTRACTOR shall utilize the process information developed for the plant process cycle and the associated PFDs and H&Ms to prepare a basic P&ID for the plant. This P&ID shall be submitted to Company. This P&ID at this early stage shall include basic items such as process equipment, process piping circuits, control loops (i.e., control valves/sensing instruments/controls), valve locations, sizes of primary piping and valves, and heat and material balance points.

4.2.5 Facility Arrangement/Plot Plan – The ENGINEERING CONTRACTOR shall add any appropriate process related information to the plain, basic facility arrangement/plot plan. This would include such information as appropriate equipment sizes and relative arrangement, and any specific process related physical constraints or requirement for the arrangement.

4.3    Detailed Process Design Scope Deliverables

4.3.1 Process Sizing Calculations – The ENGINEERING CONTRACTOR shall make appropriate calculations for the purpose of sizing process related equipment, piping, valves, and other components. These calculations shall be submitted to Company. The calculations shall cover such areas as the following:

• Process line sizes.
• Control valve sizes.
• Safety valve sizes
• Vent/flare system piping sizes including discharge lines.

4.3.2 Plant Performance Product Guarantees – The ENGINEERING CONTRACTOR shall provide a document to Company that states all guarantees associated with the plant’s process production. This document shall cover all relevant parameters for each product produced by the plant including such items as the following:

• Pressures.
• Temperatures.
• Quantities/flows.
• Compositions.
• Purities.
• Feedstock conditions and rates.
• Minimum recovery rates and efficiencies
• Energy consumption.
• Guarantee limitations.

4.3.3 Process Specification Datasheets – The ENGINEERING CONTRACTOR shall develop and submit to Company process specification datasheets. These datasheets shall cover all equipment and other components that require specific process detail information and data in order to be properly specified. Information on such details as diameters/lengths, internal distributors, packings, mist eliminators, and the like shall be provided. These datasheets shall cover such components as the following:

• Pressure vessels.
• Heat exchangers.
• Heaters.
• Reformers.
• Machinery (compressors, pumps, etc.).
• Storage tanks.
• Packaged systems.
• Safety relief valves.
• Control valves.
• Controls.
• Instruments.

4.3.4 Piping and Instrument Diagram (P&ID) – The ENGINEERING CONTRACTOR shall add any additional process information developed during the detailed design work to the basic P&ID. This information will bring the P&ID to a greater degree of completion. This information includes such items as all process line sizes, detail control valve sizing conditions, and equipment design data.

4.3.5 Facility Arrangement/Plot Plan – The ENGINEERING CONTRACTOR shall add any additional process related information developed during the detailed design work to the facility arrangement. This information shall bring the facility arrangement to a greater degree of completion. This information includes such items as equipment design data/sizes/arrangements.