Pipe Marking for Anhydrous Ammonia

ammonia pipe markingAnhydrous ammonia is widely used in food production as a cost-effective refrigerant. Although efficient, ammonia is a very dangerous chemical that can pose serious risks to those working with, or around, the substance. The corrosive properties of ammonia are extremely hazardous to human health; within just a few seconds of contact, it can burn, blister, and permanently damage skin. Inhalation of ammonia can not only cause long-term health issues, but in serious cases can even cause death. Because of this, properly labeling ammonia-carrying pipes is critical for safety and staying OSHA compliant.

In 2014, the International Institute of Ammonia Refrigeration (IIAR) updated pipe marking standards for ammonia under Bulletin 114 – Identification of Ammonia Refrigeration Piping and System Components. First published in 1991, Bulletin 114 is now accepted as an industry standard, and was based off similar standards from ANSI. It is a guideline used for identifying ammonia in pipes that not only promotes safety for employees, but can facilitate maintenance, and provide crucial information to emergency responders.

One of the most recent updates changed ammonia labels from yellow to orange to stay consistent with the 2007 revision of the ANSI/ASME pipe marking standard, making orange the color used for toxic and corrosive substances. Safety orange, as indicated in the ANSI Safety Color Code, is now a part of the recommended color scheme for ammonia labels.

An ammonia pipe marker includes the following five components:

  • Marker Body: In bold black letters against the orange label, AMMONIA is printed to identify the contents of the pipe.
  • Pressure Level Section: The pressure level is indicated with either HIGH or LOW printed on a colored band. Low pressure is represented with a green band and high pressure is printed on a red band.
  • Abbreviation Section: IIAR Bulletin 14 includes a list of abbreviations to be used on the pipe marker. Examples include Equalizer (EQ), Intermediate Pressure Liquid (IPL), Oil Drain (OD), and Relief Vent (RV).
  • Physical State Section: Ammonia flows through pipes either in a liquid or vapor state. Liquid ammonia is indicated with LIQ printed in black letters on a yellow band and vapor is indicated with VAP printed in black on a blue band.
  • Directional Arrow: Finally, a black arrow represents the direction of flow.

When marking the ammonia-carrying pipes in your facility, refer to the ANSI/ASME guidelines for size of label and text, as well as proper label placement. In addition to pipe labels, IIAR recommends marking all components of the piping and refrigeration system. One of the most effective ways to do this is by utilizing valve tags for hand and control valves. Before someone opens a particularly dangerous valve, they need to be alerted to the contents of the pipe.

Visual communication such as pipe marking keeps workers safe and ensures that your facility stays in compliance with OSHA regulations. Communicating through labels about the contents of pipes means first responders and workers can navigate your workplace with a lower risk of accident or injury. Remember: a safe facility is a successful facility.

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