The choice of which design to use is a function of how much information your operators need and the ease with which this information can be gathered. The more you put onto a valve tag, the more you will get out of it. At the very least, though, valve tags should provide a meaningful description of the function of the valve or component being identified. A summary of the designs is as follows:

3-Line Barcode. This is one of the most popular designs. Code 128 barcode is used.

3-Line, No Barcode. The component number on this tag is highlighted. It does not use a barcode.

3-Line Detailed. Similar to the three line barcode above, this design adds information that is useful for motor controlled valves and valve position (normally open or normally closed).

2-Line Classic. (Not Shown) This design does not use a barcode. It has one row for the valve number and a second row for valve description.

Vertical Valve Tag. There are many situations that demand a vertical tag. In fact, a vertical tag often hangs better on a valve. On this design, the bolder captions help you decipher the fields.

Detailed NFPA Design. Many plants have decided to add Right to Know information to their tags. It is at the valve, after all, that many leaks and accidents occur. This design is especially useful for chemicals covered by the OSHA PSM Standard.

Also see:
    Do I need to bar-code the valve tag?
    Should I use a vertical or a horizontal design?