What are ammonia pipe labels and where are they placed?

Any pipe that contains ammonia must be appropriately labeled to assure the awareness of each employee on the contents of the pipe, especially when it contains something as corrosive as ammonia. The regulations on size and color are listed in the ANSI/ASME A 13.1 ruling with the IIAR’s bulletin #114 guidelines to help contractors comply with the new standard.

To start off, there are different “types” of labels that can be used, and by this we mean material, not the content of information on the labels themselves. There are regular peel and stick labels and wrap around pipe labels. The latter is good for maximum visibility since it encases the entire pipe section in the familiar orange and black ammonia label.

Another alteration that comes with ammonia pipe labels is the size. This is dependent on how big or small the pipe is itself. The bigger the pipe the bigger the label, so everyone can see it clearly. The sizes go as follows:

Diameter (O.D.) RangeMinimum Marker WidthMinimum Marker LengthLetter SizePhysical StatePressure Level
Up to 1 and 1/4"1"8"1/2"1/2"1/2"
1 and 1/4"-2"1-1/2"8"3/4"3/4"3/4"

The last big important question is where should these labels be placed? The answer is quite simple, place it in the spot where the label is most visible. This generalization is broken up into a few other specific instances where pipe labeling needs to be apparent, those are:

  • Install labels close to valves and flanges
  • Install labels near branches or whenever a pipe changes direction
  • Install labels on both sides of a wall where any pipe goes through
  • Install every 25 ft on straight runs

If you have more questions on pipe marking, Creative Safety Supply has a multitude of pipe marking articles and guides to read. We want to give you the most information we can to help you and your company stay safe in the workplace while labeling such hazardous materials.


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