Valve tags are a specific type of tag used to identify the contents and function of a pipe that the tagged valve operates. They are an integral part of any safety system that aims to reduce the risk related to spills, accidents, and injuries from improper use of valves within a facility.
Valve tags can be made from plastic, metal, wood, or paper, and they often take the form of a small circle containing a short amount of identifying numbers or words. Larger, more-detailed tags are also available. For valves that pose an extremely high hazard due to the substances they control, valve tags are often used on top of lock-out/tag-out systems that limit access to the valve until the tagged valve lock is removed.
The use of valve tags or other valve labels is not explicitly required by the American Society of Mechanical Engineers (ASME) or the American National Standards Institute (ANSI), and valve tags are not specifically required by OSHA either. However, valve tags may still be part of a recognized safety system. A guide for plant workers by the UK Health and Safety Executive recommends the creation and maintenance of a clear system for tagging valves.
Within the United States, systems in which valve tags are expected to comply with the ANSI/ASME A13.1 standard for the proper marking of piping systems, which provides a color-coding standard and requires the tag to clearly identify the valve, are usually found to have an ID number. Furthermore, guidance from the U.S. Department of Energy states that valve tags should be permanently attached to visible components of the valve (rather than to removable parts such as a handwheel) in a manner that will allow the valve to be operated without removing the tag.
Metal tags, frequently circular tags with ID numbers, are the most popular form of valve tag due to their durability and ability to withstand harsh environmental conditions. Because many valve tags contain only ID numbers, valve tags often require the use of a valve tag log book that associates each valve tag’s ID number with the substance, hazards, and other pertinent details related to the valve and contents of the pipe that it controls.