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Standardized Line Numbers 1

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Checker855

Mechanical
Oct 22, 2007
3
Where does one find standardized line number information? We want to adopt a convention and are having a hard time finding any published. I can't imagine this is company-specific. There must be some industry standards. Thanks for any help you vcan give me.

 
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Somewhere I think I may have seen a standard but that's been a long time. Most places I've been in were company specific. Our numbering convention uses the following format: Size-Pipe Spec (internal standard number)-material desgination (internal abbreviations used)-XXXXXX(-insulation and tracing info), where XXX is a 6 digit sequential number: the first three digits denote area in the plant & the last three are purely sequential. Thus,an 8" 85 pound steam CS line with 3" of insulation & steam tracing would be something like 8"-125-S85-XXXXXX-ST&I(3").
 
The following is my answer to the same question from another Forum.

Line Numbering
The question:
“Is there a common system for line numbering and if so what is it?”

I could be wrong but I think it is safe to say there is no “common pipe line numbering system” in use in the process plant engineering and design world. There are just too many companies and people and clients and project types to be able to achieve such commonality. I don’t remember seeing anything in ASME B31.3 (or any other Code), but then again it is not the purpose of the B31 Code to dictate a line numbering system.
To properly discuss this subject we need to understand the purpose of the “Line Number.” We also need to acknowledge that some companies use the term “Line Designation.” Whether your company uses the term “Line number” or the term “Line designation” the purpose is the same. It is for line identification. This identification is necessary through out the project and is used for many purposes by different people or groups. The line numbering should be controlled by the piping group for the project and done by the piping material engineer for that project.
As with any of the other “gray hair” pipers, I too have seen many different line numbering systems in my working past. Of all of them I have determined that there are some similarities but no totally common system.
Here are some details that I have been able to determine for myself. There are two basic areas that tend to govern line numbering. These are the line number method and the line number elements.
• Methods - There are two basic line numbering “methods.” The first method is based on the Purpose or Function of the line. The second method is based on the line “Size.”
• Elements - There are many potential line identification elements that may be included in a line numbering system. The elements that are most commonly included in a line numbering scheme are: Plant Location, Line Identity, Line Class (or Line Specification), Size, Insulation Type (when required) and Heat Tracing Type (when required).
The “purpose or functional” method of line numbering is where the line is best defined as a single line having an origin and a terminus consistent with a purpose or function. An example of this might be a pump suction line. It might come from a Storage Tank, a Tower Bottom or an Accumulator. It travels some distance and then splits and connects to the two pumps designated for that one service or function. This is one line, it serves one purpose or function therefore it has only one line number. Another example would be the pump discharge that leaves both of these pumps and join to form the single pipe line that runs to the next piece of equipment. This line also has one purpose or function therefore it has only one number.
The “line size” method is where the line number changes whenever and wherever the line size changes. When compared to the first (purpose or function) method, the pump suction line might have five line numbers instead of one. The pump discharge might also have five or more depending on what happens at the destination end of the line.
One or the other of these two methods becomes the “Rule” for a company, client or project. As we all know, for every rule you will always be able to find an exception. One exception that is common to both of these “Rules” is the rule of the change of line class (or line specification). The change in line class is most often caused by a change in pressure or material. A line might be the same size from one point to another but includes a pressure control valve that lets the pressure down to a level that allows a lower flange rating and or another material therefore a different line class. There are other line class change initiators but I think you get the idea. Any change in a lines conditions or material causes a mandatory change in the line number no mater which line numbering method is being used.

The elements of a line number might be arranged and look something like this:

10-0021-CA1A-12”- IH –ST or HC-1021-CA1A-12”- IH –ST -The Bold portion is the actual line number or line identification. It is much like a person’s first, middle and last name. All the other information is considered a minor qualifier some what like a person’s height, weight or profession.
Where:
10 = the plant Unit, Area or jurisdiction (mandatory) (1)
Or
HC- = the commodity code for what is in the line (1)
0021 or 1021= the numeric line number (mandatory)
CA1A = the line class (mandatory)
12” = the line size (mandatory)
IH = Hot Insulation (only when required) (2)
ST = Steam Tracing (only when required) (3)

(1) – Unit and Area includes the division between onsite and offsite. Jurisdiction includes the division of work between a licensor and the prime contractor. When the commodity code method is used then the leading number of the numeric portion of the line would be used for Area/Unit separation.
(2) - Other types of insulation include IC = Cold Insulation, IS = Safety Insulation, IA = Acoustic (or Sound) Insulation, etc.
(3) - Other types of tracing include: ET = Electric Tracing, CWT = Chill Water Tracing, TT = Thermon (Hot Oil) Tracing, etc.

I have no doubt that there are other items of information that could be or are added in some form or another based on the preference of a specific company of client. My credo is “Keep It Simple.” The manner of arranging the Elements to form a line number is something that is also dictated by the Company and or in some cases the Client. The sequence that is shown above is in the order of information priority that I am used to.

The line numbering activity should only be done when the P&ID’s are well along in the development process. The more complete the P&ID’s are the less hours will be wasted and the better the results of the line numbering effort. The degree of P&ID completeness prevents recycle when new equipment or systems are added or when equipment or systems are deleted.

Line List (Line Table)
As the Piping Material Engineer (or designate) performs the line numbering of the P&ID he or she also initiates the first draft of the Line List (or Line Designation Table) data base. The resultant document from this data base will be extensive for a whole project but will be broken down by plant area.


In addition to the line identification elements (indicated above), the Line List (data base and document) will or should also include important information for the design process and construction process such as the following:
• The line commodity
• The phase (liquid or gas)
• The origin of the line
• The destination of the line
• The line pressure, both the normal operating pressure and the maximum operation (or Design) pressure
• The line temperature, both the normal operating temperature and the maximum operation (or Design) temperature
• An indicator code for Stress Analysis requirements
• PWHT requirements
• The insulation thickness (optional)
• The line schedule (optional)

The line list once initiated will have many additions, deletions and be used by lots of people throughout the project both in the design office and in the field.

One of the first and most important activities where the line list is used is when the definitive labor hour estimate in generated. The number of lines on a project has a direct bearing on the labor hours required. This is true for the piping design activities in the home office, the pipe fabrication shop and for the installation contractor in the field. So it is very important to get it right.

 
Thanks, SK

We too have a standard pipeline designation convention. I know the military also has one (or more). We have an opportunity to redesign this convention due to a new software system. I was hoping to follow something at least industry-specific (ours is petrochemical). I am very suprised to not be able to find anything.
Thanks again

 
Thank you, Penn. Your reply couldn't have been more informative. We use a similar convention, which is very similar to all line designations that I have seen.

If I may focus on the 'commodity code'. Do you know of a standard on this for process plants? I know most of it is common sense (CWS, CWR, etc.), but sense is rarely common. Instead of me proposing a convention to my organization and having every engineer and his brother trying to fight for the version he likes, I would like to be able to cite a standard to eliminate as many arguments as possible.
 
There is an internationally used system, KKS, for process/ power plant identification, this is mostly for pieces of equipment but there may be some info reg pipelines.
There is also ISO 1219 which may offer some more references. Just google it, it may help.
 
PIP PNCM0002
Piping Material Specifications Line Class Index
 
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