How much do you know about pipe numbering in P&ID diagrams?

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Piping and instrumentation diagrams are an important part of chemical process design. During the design process, all the equipment, instruments, pipes, valves, and other related utility systems of the system should be detailedly represented in accordance with the requirements of the entire process flow diagram. Next, the guide will take you through a comprehensive understanding of the design specifications for piping and instrumentation diagrams, as well as the design methods for various equipment used in the chemical industry, such as pumps, containers, towers, heat exchangers, and air coolers. Pipe numbering objects I. Pipe numbering objects The pipe numbering specified in these guidelines applies to Piping and Instrumentation Diagrams (PI diagrams); all pipes shown on such diagrams must be numbered, with the following exceptions. 1. Pipes that are processed and installed together with the equipment and machinery, namely those for which the seller (manufacturer) provides detailed PI diagrams or pipe layout drawings, eliminating the need for an engineering design firm to create pipe layouts; such pipes do not require material estimation, and include: (1) pipes supplied by the seller (manufacturer) as part of the complete set of equipment or unit. (2) Pipes inside equipment and machinery. For example: insertion tube (a section inserted into the device), internal heat exchange tube, etc. 2. The equipment ports are connected directly (no pipes are needed in between). For example: stacked heat exchangers, towers, and adjacent reboilers, etc. 3. Connection ports on the equipment at which valves, blind flanges, or plug plugs are connected directly, without any piping in between. For example: the device’s own drain ports, vent ports, pressure testing ports, leak testing ports, spare ports, and connections to utility systems. If pipes are connected behind the valves at these ports, those pipes must be numbered. 4. The vent pipes and drain pipes on the pipeline refer to the liquid discharge pipes that lead to the floor surface (rather than to gutters or pits), as well as the inlet ducts of safety valves that discharge directly into the atmosphere (such safety valves do not have outlet ducts). 5. The heat tracing pipes and jacketing pipes on the equipment, machinery, and pipelines are not numbered on the PI diagram. 6. The bypass pipes of control valves, the small fittings used for switching, or the identical spare (or bypass) pipes of valve assemblies. 7. Instrument pipelines, such as pressure gauge connections and various instrument signal pipelines.