Old K says every week – Talking about things in the petrochemical design industry. Post 15: Explanation of PID versions and management of PID modifications

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This post was last edited by henglinkou on 2020-9-19 at 15:35. Old K’s weekly series – Talks about things in the petrochemical design industry, Post 15: Explanation of PID versions and management of PID modifications. Piping and instrumentation diagrams are abbreviated as PID; abroad, they are usually referred to as P&ID. The PID is a very important design document for petrochemical projects; poor management of its versions and modifications can lead to chaos in the design process. Process designers often encounter situations where downstream disciplines complain about frequent updates and modifications to PIDs. Sometimes, certain downstream disciplines end up using PID versions that are not the latest ones. Even within the process engineering discipline itself, there are instances of confusion regarding PID versions. Before the design process begins, it is necessary to define the version of the PID appropriately based on the specifics of this project and include that definition in the design plan. The design manager and the person in charge of the manufacturing process should pay close attention to this; in reality, however, many projects do not give sufficient importance to this aspect. In accordance with international practice, during the engineering design phase, the PID is divided into seven versions. For projects with relatively simple PID diagrams, the number of PID versions can be simplified. According to international practice, the definitions of PID revisions are as follows (excerpted from the 5th Edition, Volume 2 of the Chemical Process Design Manual): Revision Description Revision A (Preliminary Conditions Revision) Upon receiving the main contents of the basic design requirements for the PID, process system engineers can commence the PID design work, without having to wait until the entire process package is finalized, thereby shortening the design cycle. Version A of the layout primarily reflects the overall relationships among components such as processes, equipment, piping, and instruments. It is used for the arrangement of equipment within the plant, the determination of the routes of main pipelines, the analysis of special pipelines and pipe racks, as well as to support professional fields such as automatic control in carrying out basic engineering design. Version A of the layout must include at least the following elements. (1) List all devices, machinery, drives, and spare units with their designations; for devices whose designations have not been determined, this should be indicated in the remarks column, or the device designation can be temporarily represented using a generic symbol or a rectangle. The main technical data and structural materials should also be indicated initially. (2) For the main process pipeline materials (including those used intermittently), indicate the material code and nominal diameter; the pipeline sequence number, pipeline grade, and insulation/acoustic insulation codes may be omitted for now, but the flow direction of the material must be indicated. (3) For the utility and auxiliary material pipelines connected to equipment or pipes, the material code and nominal diameter should be indicated; sequence numbers, pipe grades, and insulation or soundproofing codes may be omitted temporarily, but the flow direction of the medium must be specified. The material code for steam pipes should reflect the pressure rating, such as LS, MS, HS. (4) The main valves that play a role in controlling and regulating the manufacturing process should be indicated. Secondary valves, fittings, and special pipes (valves) on the pipeline can be omitted temporarily; if they are to be shown, no numbering or labeling is required. (5) The main safety valves and rupture discs shall be marked, but not their dimensions and numbers. (6) No dimensions, numbering, or additional bypass valves are required for all control valves. (7) Indicate the main monitoring and control instruments as well as their functional identifiers (the primary components, transmitters, auxiliary instruments, and accessories, etc., need not be shown one by one, nor must circuit numbers be provided); specify the locations where the instruments display information and perform control functions, such as on the host computer, in a DCS system, or at various locations on-site. (8) Indicate any special requirements regarding the pipe material (such as alloy materials, non-metallic materials, high-pressure pipes, etc.) or specify the pipe grade. (9) Indicate the requirements of the pressure relief system and the release system. (10) Necessary key elevations (minimum dimensions) and key design dimensions of the equipment, requirements for the specific layout of equipment, pipelines, and instruments, as well as other key design requirements (such as pipeline symmetry requirements, vacuum pipelines, etc.). (11) Scope of supply for complete (matching) equipment and scope of responsibilities of the design unit. (12) Text codes, abbreviations, various graphic symbols on the home page, as well as instrument graphic symbols. (13) Piping and instrumentation diagrams for auxiliary materials, utility materials, as well as those for pipelines between units are prepared only for preliminary purposes and are usually not included in the Version A diagram. PID Version B (Internal Audit Version): The PID must first undergo an internal audit before being submitted to the owner for review. The Process (System) discipline must conduct safety analyses and necessary calculations before completing Version B of the layout; after work by various disciplines and relevant discussions, Version B is developed and finalized based on Version A. Apart from objective constraints such as limitations in the design phase and manufacturer conditions, as well as incomplete drawing materials, the Version B layout should be as complete as possible. Based on the content of Layout A, Layout B should also include the following elements. (1) Install all process, utility, and auxiliary material pipelines, and label them with pipeline numbers, including start-up and shutdown pipelines, as well as purging, displacement, and regeneration pipelines. For different grades within the same pipeline, boundary symbols must be indicated. (2) The connection dimensions of equipment (such as pumps, compressors, special machinery, etc.) for which the manufacturer has already provided conditions, drawings, and documents, along with the required auxiliary material systems and shared material systems. For example: cooling, lubrication, sealing, venting, and draining; the diameter of the connection pipes in the system, the types of connections, relevant standards, and design requirements. The drawings are prepared based on the amount of information received. (3) Supplement all testing and control instruments as well as functional labels, and assign circuit numbers, except for the instruments supplied randomly by the manufacturer. (4) Add all equipment, machinery, drives, and spare units listed with their serial numbers, and assign them numbers and labels. Replace all special pipes (valves) and components, and number and label them. (5) Identify all sampling and analysis points, and number and label them. (6) Label and number the flow control orifice plates, safety valves, rupture disks, steam traps, and pressure relief valves. (7) Markings of control valve details, such as the presence or absence of a handwheel, the open/closed positions of valves in emergency situations, and the bypass valve assemblies, etc. The dimensions of the control valve (or the reducer pipes before and after the control valve) can be left unspecified for now. (8) Details requiring clarification and pending (hold) issues. (9) Improve the content related to the homepage image. (10) P&ID and distribution diagrams for auxiliary materials and utility materials (utility material generation diagrams and utility material distribution diagrams), as well as P&IDs for pipelines between units; Version B will also be published with similar content. Version C of the PID (user-approved version) is prepared after an internal review by the design team; the process (system) engineering department then incorporates the changes and suggestions that have been agreed upon among all relevant teams, including the commissioning engineers, into the P&ID diagram, resulting in Version C of the diagram for user review. The contents that need to be added for Version C are generally as follows. (1) Content of the additional information provided by the manufacturer. (2) All valves deemed necessary by the process (system) engineering department, as well as all special pipes (valves). (3) Supplement and improve all pipeline requirements and pipeline markings. (4) According to the instrument composition of each circuit and the determined instrument types, indicate the instrument symbols in detail; for certain instrument types in individual circuits where a determination cannot be made at present, a simplified method can be used. The requirements for utilities, anti-freezing measures, and heat tracing for the instruments are clearly specified. (5) The technical characteristic data of equipment, machinery, and drives must be accurate; the scope of the complete sets of equipment as well as the division of responsibilities in design should be clear, with boundary lines for various categories indicated along with the corresponding drawing numbers. (6) Clarify the scope of all pending (hold) issues. Version C ensures 95% integrity and accuracy, allowing users to conduct a thorough review of whether the design meets production requirements. After the PID Version 0 (design version) C-layout is sent to the user, the user will organize relevant experts to conduct a review. The project (design) manager of the design firm, along with professionals in areas such as process engineering, automatic control, and piping, attend the review meeting for discussion. Based on the formal written review comments provided by the review committee, Version C of the P&ID was modified and supplemented, ultimately resulting in the completion of Version 0 of the P&ID. Version 0 serves as the basis for the detailed design of equipment layout drawings, piping layout drawings, detailed model piping, and related disciplines. PID Version 1 (Detailed Design Version 1) is prepared by the process (system) and piping specialties in conjunction, based on the equipment layout drawings, pipe layout drawings, and models, as well as the pipe diameters determined through detailed hydraulic calculations carried out using the piping diagrams; thereafter, the P&ID Version 1 is issued. However, the amount of modification should be very limited, generally less than 3% to 5%. Generally, the following contents need to be added in Version 0 layout. (1) Final information provided by the manufacturer. (2) After returning to the process (system) discipline based on Version 0 layout, the piping, automation, and other disciplines modify the Version 0 PID diagram according to the changes and adjustments made to that layout. PID Version 2 (Detailed Design Version 2): The version 2 drawings are released only when necessary. It is only necessary to issue one when there are changes in the equipment selection or specifications during the process flow or equipment ordering. Generally, the following contents need to be added on one layout. (1) After the relevant specialties (such as piping, automation control, machinery, and pumps) make modifications to the first version of the PID diagram, they send back the changes made by the process (system) specialty. (2) Modifications made by the manufacturer to the ultimately provided materials. PID Version 3 (Construction Version) This version of the diagram serves as a basis for construction, installation, preparation of operation manuals, guidance for commissioning, production, and accident handling. Regarding the “pending” issues in Version 3 that arose because final data could not be provided due to external conditions, the design manager was informed via memorandum; once the conditions are met, the process (system) specialists should proceed with completing them. After the 3rd version of the drawings is released, further releases will not be made as a complete set; instead, only minor changes will be made to individual PID values that require modifications or to address issues marked as “pending”, and these changes will be published separately. Regarding the content and depth of P&ID Version 3, the following points should be noted. (1) It shall meet the requirements of the manufacturer’s drawings and documents, as well as the requirements specified by the commissioning engineer. (2) All indications for venting and draining on the diagram must be present; (3) The connection relationships shown in the drawings, as well as the boundary intersection points, must be complete and accurate. (4) All modification symbols and modification range lines indicating changes on the diagram should be erased. (5) Handling suggestions for all “pending” issues and issues that require clarification. Regarding the management of modifications to PID diagrams, it is common practice to use cloud-shaped lines on the diagram. Compared to the previous version, areas that have been modified in this version are marked with such cloud-shaped lines. Every modification to the PID must undergo review before it can be released. Additionally, it is recommended to create a PID modification management table (which can be an Excel sheet) from the start of the project; this approach is simple, clear, and allows for tracking. The recommended format for the management table is as follows: PID, Management Table. Columns include Serial Number, Modification Date, Content of PID Serial Number Change, and Reason for Change. Lao K writes about various aspects of the petrochemical design industry on a weekly basis; please refer to the following links for previous posts: Post 1: The Development History of China’s Survey and Design Industry – https://bbs.hcbbs.com/thread-3031149-1-1.html. Post 2: **Management in the Survey and Design Industry** – https://bbs.hcbbs.com/thread-3036417-1-1.html. Post 3: The Development of Drawing Techniques in Design Institutes – https://bbs.hcbbs.com/thread-3039960-1-1.html. Post 4: The Evolution of Specialization within Petrochemical Design Institutes – https://bbs.hcbbs.com/thread-3045261-1-1.html. Post 5: The Organizational Structure of Petrochemical Engineering Companies – https://bbs.hcbbs.com/thread-3050591-1-1.html. Post 6: Contract Management in Design Management – https://bbs.hcbbs.com/thread-3054762-1-1.html. Post 7: Management of Basic Design Data in Design Management – https://bbs.hcbbs.com/thread-3058184-1-1.html. Post 8: Quality Management in Design Management – https://bbs.hcbbs.com/thread-3061718-1-1.html. Post 9: Schedule Management in Design Management – https://bbs.hcbbs.com/thread-3062161-1-1.html. Post 10: Document Management in Design Management – https://bbs.hcbbs.com/thread-3069580-1-1.html. Post 11: Meeting Management in Design Management – https://bbs.hcbbs.com/thread-3073327-1-1.html. Post 12: Bonus Distribution Management in Design Management – https://bbs.hcbbs.com/thread-3077492-1-1.html. Post 13: The Construction Process for Petrochemical Projects – https://bbs.hcbbs.com/thread-3082708-1-1.html. Post 14: Illustrations of the Content and Procedures of Process Design – https://bbs.hcbbs.com/thread-3086849-1-1.html