【Y2025】Contents and Considerations for the Review of Instrumentation Construction Drawings (Detailed Engineering Design)

Text outside the attachment, for reference only. Automation instrument engineering designers, in accordance with the engineering construction guidelines and policies, design codes, and standards set by ** and local authorities, and taking into account relevant information regarding the location of the project such as geological, topographical, hydrological, meteorological, transportation, energy, and resource conditions, as well as the specific requirements and suggestions put forward by the project owner, prepare a series of drawings based on the approved preliminary design or expanded preliminary design. By applying principles of drafting and using legends, symbols, letters, codes, line types, numbers, and text that are standardized nationally or within the industry, they illustrate the installation locations of instrument equipment, instrument pipelines, instrument circuits, their laying methods and routes, as well as the interrelationships with other disciplines such as electrical systems, process equipment, and piping systems. These drawings also show the actual shapes, sizes, specifications, models, and materials used. Along with necessary textual descriptions, this entire set of drawings is referred to as the construction drawings for automation instrument projects (abbreviated as instrument construction drawings).

Text outside the attachment, for reference only. Instrumentation construction drawings are important tools used in instrument installation to express and communicate technical concepts. Designers use it to convey their design concepts, constructors use it for installation work, and users rely on it to guide usage, maintenance, and management. Engineering budgeters use it to calculate project costs; that’s why people often refer to instrument construction drawings as the universal language of instrument engineering. Each set of construction drawings for the installation of engineering instruments is intended not only for use by the aforementioned personnel but also for various departments involved in the project’s construction (such as the owner’s superior authorities, the planning department in the location where the project is carried out, and the document management department, etc.). Therefore, a larger number of copies are usually made. Since these copied drawings are typically in blue, they are conventionally referred to as \"blueprints\".

Text outside the attachment, for reference only. Construction drawings are the \"engineering language\" for all relevant aspects of project construction, and they remain valid for a long time. Therefore, the construction drawings must be accurate, neat, concise, and clear; all relevant elements must be consistent with one another and free of contradictions. All legends, symbols, and codes shall comply with **relevant regulations and requirements.

Text outside the attachment, for reference only. The design instructions are located at the center of the entire set of drawings. All technical, quality, and safety-related issues that cannot be shown on the drawings but which it is necessary for the constructors to understand, as well as all matters that need to be explained, generally have to be described in writing. The design specifications serve as a means for designers to fully express their design concepts and principles. There is no unified standard format for the specifications related to instrumentation installation; since the specifics of each project vary, there can be significant differences between them.

Text outside the attachment, for reference only. The amount of information specified in the design instructions varies; generally, the design instructions include the following contents. ①Design basis, components of the design documents, approving authorities, engineering contracts related to the design basis, documents approved by higher authorities, etc. ② Design scope: the scope of design for this project, contracts, contents, scope of supply, etc.; especially in the case of Sino-foreign joint ventures or imported project designs, it is necessary to clarify the principles for dividing the design tasks as well as the respective design scopes of Chinese and foreign parties. ③Specify the name of the implementation standard. ④Clarify the nature of the project: new construction, expansion, or renovation project. ⑤ Construction requirements, characteristics of this project, technical requirements during construction, etc. ⑥Requirements regarding safety and quality during construction, as well as precautions. ⑦Issues related to specialized division of labor and coordinated professional construction. ⑧Other issues that need to be addressed.

Text outside the attachment, for reference only. The floor plan*, commonly referred to simply as a plan, is the drawing in the instrumentation construction drawings that provides the most comprehensive and detailed representation of the overall installation details. There are plans for the layout of instrumentation equipment, plans for the layout of instrumentation cable trays, plans for the layout of instrumentation pipelines, and plans for the layout of instrumentation circuits, among others. In short, determining the installation location, direction, laying height, and so on all requires to be represented using a floor plan. The three elements in a plan are plan dimensions, drawing scale, and elevations

Text outside the attachment, for reference only. An instrument system diagram is a drawing that classifies instruments by system and shows the overall structure of that instrument system. It typically includes diagrams of the instrument system itself, the air supply system, the heating system for instruments, and the grounding system, etc., and it reflects the structure of the instrument equipment and materials that make up the instrument system.

Text outside the attachment, for reference only. An instrument circuit diagram is a diagram that shows the composition of an instrument circuit; it indicates, based on the series of instrument identifiers, which instrument devices are involved in the sensing and control circuits, as well as the connection relationships between them. It is convenient to understand the entire circuit through the circuit diagram.

Text outside the attachment, for reference only. To understand schematic diagrams, one needs to know the control principles behind the systems used for instrument detection, control, and interlock alarms. It is necessary to comprehend the basic principles of these internal systems, the control principles according to which they operate, the relationship between inputs and outputs, as well as various control rules – all of this can be understood through schematic diagrams. (Logic diagram, sequence diagram)

Text outside the attachment, for reference only.