Ammonia Component Marker Requirements

This is an update to a blog that was originally posted on 5/25/15. You can read the original blog here.

New Ammonia Refrigeration Systems

For new ammonia refrigeration systems, all vessels and equipment (compressors, condensers, etc.) must follow the component marker requirements in ANSI/IIAR 2-2021 §4.2. The standard states the following in regard to component markers:

• Component markers should bear the name of the equipment they identify, e.g., RECEIVER, ACCUMULATOR, RECIRCULATOR, etc. Additional information can be provided.
• Component markers should have BLACK letters on a SAFETY ORANGE field.
• The material used for component markers should be in accordance with paragraph 4.3.
• Colors for component markers are described by the ANSI Z535 Safety Color Chart.

The example image of a component marker included in IIAR 2 is shown below:

[Note: Prior to March 2014, IIAR Bulletin No. 114 recommended SAFETY YELLOW as the background color for component markers. Refer to a previous blog post for more information.]

Regarding component marker dimensions and lettering sizes, IIAR 2 states the following:

• Component markers should be approximately 3-1/2″ wide and long enough to accommodate the name of the component.
• Lettering on component markers should be 2-1 /2″ high.

The name of the equipment written on the component marker should be helpful to an operator, contractor, or a first responder that is unfamiliar with the equipment. If three compressors are labeled simply as “COMPRESSOR”, this may pose a problem when differentiating between Compressors #1, #2, and #3.

Types of equipment that often lack a component marker include:

• Oil Pots
• Ammonia Pumps
• Auto-Purgers
• Oil Separators
• Plate and Frame Heat Exchangers
• Oil Coolers

If these components are installed in your system, it is recommended they be equipped with a component marker as described above.

Existing Ammonia Refrigeration Systems

Existing ammonia refrigeration systems are subject to the requirements of ANSI/IIAR 9-2020. This is the Standard for Minimum System Safety Requirements for Existing Closed-Circuit Ammonia Refrigeration Systems. According to the standard, “Refrigeration equipment shall be provided with labels indicating the equipment’s name or identifier.” (7.2.9.2)

As you can see, there are no specifications regarding letter sizing, or component marker color. Existing systems are allowed more flexibility than the rigid requirements in IIAR 2. However, common sense should be used when installing component markers. Factors like the size of the component marker and placement should be considered to ensure the component marker is easy to read, and will not be covered by frost.

Regardless of whether a system is subject to strict labeling requirements or not, component markers are crucial for avoiding confusion, and alerting employees to the presence of ammonia equipment.