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Ammonia Facility Pipe Colors and Markings

Overview 

International Institute of Ammonia Refrigeration (IIAR) Bulletin No. 114 defines the pipe marking standard for ammonia refrigeration systems, building on the general requirements of ANSI/ASME A13.1.  (Bulletin 114 was previously referred to as bulletin 14). 

The exact labeling and color coding of ammonia piping and system components may vary, including changes based on when the system, or portion of a system was installed.  Always verify with the ammonia system owner/operator.  

Ammonia Specific Pipe Colors (Older Systems) 

Some refrigeration systems may have painted the piping to indicate the physical state, pressure, and temperature of the ammonia in the pipe.  This was an industry best practice only for facilities with ammonia refrigeration systems.  When ANSI standard A13.1 was created, it codified a pipe color coding system for all of industry, not just ammonia.  Under ANSI A13.1, Ammonia is treated a corrosive/toxic gas and ALL ammonia pipes are color coded orange with black text.  
Some ammonia systems may continue to use Orange and Yellow pipes for liquid and vapor.  

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See Pipe Color Codes Page 

Older Ammonia Pipe Color Codes Prior to ANSI A13.1

  • High Pressure Liquid: Orange (Pantone 152C)
  • High Pressure Vapor: Yellow (Pantone 109C)
  • Low Pressure / High Temp (Liquid & Vapor): Light Blue (Pantone 298C)
  • Low Pressure / Low Temp (Liquid & Vapor): Dark Blue (Pantone 3015C)
  • Low Pressure / Low-Low Temp (Liquid & Vapor): Purple (Pantone 2617C)
  • Relief Vent Piping: Gray
  • Water / Glycol: Green


Ammonia Pipe Markers (Labels)

Ammonia pipe markers will contain five sections of information including: 

  1. Abbreviation Section: Printed in black
  2. Physical State Section: Either LIQUID or VAPOR
    Printed in yellow for Liquid and sky blue for Vapor
  3. Marker Body: Body color to be Safety Orange and contain the refrigerant "AMMONIA" printed in black
  4. Pressure Level Section: Either LOW or HIGH.
    Pressure in excess of 70 psig will be considered to be high pressure and printed in black letters on a red band.
    Pressure equal to or less than 70 psig will be considered to be low pressure and printed in black on a green band.
  5. Directional Arrow: Detachable arrow printed in black.

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Pipe Marker Label Abbreviations 

International Institute of Ammonia Refrigeration (IIAR) Bulletin No. 114 includes 31 approved abbreviations for ammonia pipe markers.  

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Ammonia Refrigeration System Components / Equipment 

Ammonia refrigeration system vessels and major components should be labeled as follows:

  • Background: Safety orange with black lettering.
  • Dimensions: Typically 3.5 inches wide by a length proportional to the equipment name.
  • Text Size: Equipment names should be feature lettering 2.5 inches high.
  • Content: Identifies the specific vessel or component name (e.g., "RECEIVER")

Prior to March 2014, IIAR Bulletin No. 114 recommended SAFETY YELLOW as the background color for component markers. 

 


This page is educational purposes.  It is not for compliance, or a substitute for IIAR bulletin 114 or ANSI standards.  Always reference the original documents
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