Ammonia Pipe Labeling Requirements – IIAR & ASME/ANSI

Ammonia is an incredibly useful gas that is used in refrigeration. While ammonia is produced by the human body and found throughout nature, it can still become harmful when not handled correctly. Pressurized anhydrous ammonia serves as a prominent choice for commercial refrigeration owing to its remarkable heat absorption capabilities. Various industrial sectors, such as food and beverage processing, cold storage, and meatpacking, rely on its usage. However, stringent adherence to ammonia pipe labeling regulations is imperative within these environments. In the ensuing discussion, we will delve into the standards and prerequisites, encompassing the color codes, lettering specifications, and positioning stipulated by ANSI/ASME, alongside the directives outlined in the International Institute of Ammonia Refrigeration's IIAR Bulletin 114. Prior to delving into these standards, it is crucial to grasp the hazards associated with ammonia and underscore the significance of employing pipe labels and tags to mitigate risks associated with this potentially perilous chemical.

Dangers of Pressurized Anhydrous Ammonia

The hazards posed by pressurized anhydrous ammonia are significant. Uncontrolled releases of this compound can pose dangers to human health, being corrosive and potentially explosive if not properly managed. Anhydrous ammonia is classified with a health hazard rating of 3 on the NFPA fire diamond due to its potential threats, which include:

• Irritation and corrosion to the skin, eyes, respiratory tract, and mucous membranes.
• Severe chemical burns and frostbite to the eyes, lungs, and skin.
• Exacerbation of existing skin and respiratory conditions.

The EPA has documented numerous accidents involving anhydrous ammonia, such as a case in a meat-packing plant where a refrigeration line ruptured, resulting in eight workers sustaining critical injuries due to respiratory burns from inhaling ammonia vapors.

The Importance of Ammonia Pipe Labeling

The significance of labeling ammonia pipes is paramount. Adhering to proper labeling standards aids workers and emergency responders in accurately identifying pipes and tracing their paths, crucially leading to valve shutoffs to mitigate further releases. Pipes marked according to IIAR standards not only enhance safety protocols but also serve as valuable tools in training both existing and incoming employees, facilitating efficiency during maintenance and servicing operations. Incorporating appropriate lockout tagout mechanisms, such as valve lockouts, alongside clear labeling, guarantees the safety of you and your team during such critical events. There are also best practices to meet pipe marking guidelines so the labels are easy to find and read.

Ammonia Pipe Marking Guide: Color Code, Lettering, and Positioning

An ammonia pipe label typically consists of five distinct sections, each adhering to specific color codes and regulations:

Marker Body (Ammonia):The body of the marker should be safety orange, with the word "AMMONIA" printed in black letters.

Physical State (Liquid, Vapor, or Both):Depending on whether the ammonia is in a liquid, vapor, or both states, different guidelines apply:

• Liquid: "LIQ" in black letters on a yellow band to the left of "AMMONIA."
• Vapor: "VAP" in black letters on a sky blue band to the left of "AMMONIA."
• Both Liquid and Vapor: Follow the guidelines for liquid and vapor, adding "VAP" to the left of "AMMONIA" and "LIQ" to the left of "VAP."

Pressure (High or Low): The pressure level determines the designation:

• Pressure greater than 70 PSIG: "HIGH" in black letters on a red band to the right of "AMMONIA."
• Pressure less than or equal to 70 PSIG: "LOW" in black letters on a green band to the right of "AMMONIA."

Abbreviations (HTRL, LTRS, etc.): Various components of industrial ammonia refrigeration systems are identified using abbreviations, which should be printed in black letters on the safety orange field to the left of the physical state.

4. Ammonia System Abbreviations

Abbreviation	System
BD	Booster Discharge
CD	Condenser Drain
DC	Defrost Condensate
ES	Economizer Suction
EQ	Equalizer
HG	Hot Gas
HGD	Hot Gas Defrost
HPL	High Pressure Liquid
HSD	High Stage Discharge
HSS	High Stage
HTRL	High Temperature Recirculated Liquid
HTRS	High Temperature Recirculated Suction
LIC	Liquid Injection Cooling
LSS	Low Stage Suction
LTRL	Low Temperature Recirculated Liquid
LTRS	Low Temperature Recirculated Suction
PO	Pump Out
PU	Purge
RV	Relief Vent
TSR	Thermosyphon Return
TSS	Thermosyphon Supply
* Not currently covered in the IIAR standard

Directional Arrow (← →): Black directional arrows, proportionate in size to the marker, may be included to indicate flow direction. These arrows can be applied around the full pipe circumference as needed.

To indicate ammonia refrigerant flow direction, directional arrows are illustrated on the pipe marker. 2 of Seton’s 3 ammonia pipe marking options, Setmark® Snap-Around Ammonia Pipe Markers and Ultra-Mark® Self-Adhesive Ammonia Pipe Markers ammonia pipe markers, come with directional arrows on the marker. The Opti-Code™ Self-Adhesive Ammonia Pipe Markers version does not include arrows, thus making Seton’s Arrows-On-A-Roll tape a great accessory.

Finally, stay on top of safety guidelines. Keep up with IIAR best practices and take steps to understand the OSHA color codes for pipe marking. You can use these guides to purchase pipe markers and labels that meet the latest standards for protecting employees.

Uncertain about the number of pipe markers required for your task? Utilize our convenient Pipe Marker Calculator or reach out to Seton Contractor services for assistance. Let us handle the heavy lifting with our pipe marker take-off service. Call us at 800-243-6624.