Complicating simple problems! Common problems in the assignment of instrument tag numbers!

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In the fast-paced environment of modern engineering construction, the planning of instrument tag numbers in chemical enterprises is often neglected, which makes subsequent maintenance tasks particularly complex. Many companies fail to carry out a systematic planning for the assignment of instrument tags across the entire plant, which leads to a range of problems and causes significant difficulties in daily management. This paper will delve into the common problems prevalent in the process of instrument tag numbering within chemical enterprises, as well as the influencing factors behind these issues. During the engineering construction process, some chemical enterprises failed to plan instrument numbers on a plant-wide basis, which makes subsequent maintenance particularly difficult. Looking at the way instrument numbers are assigned in these enterprises, several common problems can be observed: 01 Disordered instrument numbers, which is manifested by a complete lack of pattern and by the failure to follow any naming rules. If the unit numbers and sequence numbers are not assigned according to the rules, in the same process some instrument tag names are TE-201, while others are TE-1301 ； Or the DCS function symbols and instrument tags are not distinguished; for example, if the level gauge tag for a certain device is LT-213, level indication and alarm (LIA) functions are implemented on the DCS. When drawing a P&ID, a simplified approach is used, and the resulting instrument tag becomes LIA-213. 02 Duplicate instrument tag numbers: This situation occurs when the same instrument tag number is used in different workshops, or when the instrument tag numbers provided by a complete set of equipment are identical to those of other instruments in the system. For example, if each individual unit is assigned tag numbers starting from 001, focusing only on the sequence numbers without assigning device numbers or unit numbers, then multiple instruments with tag numbers such as TE-001 may end up existing within one factory. 03 Instrument tag numbers are difficult to remember. In many companies, the instrument tag numbers assigned are not easy to recall, which prevents field technicians from determining to which unit or area a particular instrument belongs; this results in additional time being spent searching for relevant information during maintenance tasks. After the factory is built, process and instrumentation technicians must spend a great deal of time memorizing the equipment corresponding to these tag numbers, which is not only time-consuming but also prone to confusion. Over time, operators may use locations to replace tag numbers, such as “the thermometer on the second floor of the methanol distillation tower” in place of “TT-13056”. There are rules for assigning instrument tags, and good rules facilitate the lookup and memorization of these tags, thereby providing great convenience for instrument engineering design and on-site maintenance. Currently, there are various methods for assigning instrument tags in the chemical industry. This article discusses the advantages and disadvantages of each method to serve as a reference for design purposes.