Ammonia Pipe Marking
International Institute for Ammonia Refrigeration (IIAR)
Ammonia Refrigeration Pipe Marking Guide
The International Institute of Ammonia Refrigeration (IIAR) has published bulletin #114, which is called "Guidelines for Identification of Ammonia Refrigeration Piping and System Components," to provide a standard system for ammonia pipe labeling. When labeling pipes containing ammonia, the ammonia pipe markers should contain the elements shown in the figure below.
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System Component Abbreviations | |||
| BD | Booster Discharge | CD | Condenser |
| DS | Defrost Condensate | ES | Economizer Suction |
| HGD | Hot Gas Defrost | HPL | High Pressure Liquid |
| HSD | High Stage Discharge | HSS | High Stage Suction |
| 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 |
| RV | Relief Vent | TSR | Thermosyphon Return |
| TSS | Thermosyphon Supply | ||
This ammonia pipe marking guide is intended for general information purposes only. This guide is not a substitute for review of applicable government regulations and standards.
LIQ - Orange color band indicates liquid state
VAP - blue color band indicates vapor state
Use both color bands if both liquid and vapor may be present.
High - Red color band indicates high pressure
Low - Green color band indicates low pressure
1. Use arrows at both ends to indicate the direction of
ammonia flow in the pipe.
2. Use the abbreviations shown in the table to identify system
components.
3. Indicate whether the refrigerant is a liquid, vapor or both:
4. LIQ-Use black or white text on an orange color band for
liquid ammonia.
5. VAP-Use black or white text on a blue color band for
ammonia vapor.
6. LIQ/VAP-Use both color bands if both states may be
present.
7. Print AMMONIA in black letters on a yellow background.
8. Indicate whether the internal pipe pressure is high or low:
9. HIGH pressure: Use black or white text on a red color band.
10. LOW pressure: Use black or white text on a green
color band.
VAP - blue color band indicates vapor state
Use both color bands if both liquid and vapor may be present.
High - Red color band indicates high pressure
Low - Green color band indicates low pressure
1. Use arrows at both ends to indicate the direction of
ammonia flow in the pipe.
2. Use the abbreviations shown in the table to identify system
components.
3. Indicate whether the refrigerant is a liquid, vapor or both:
4. LIQ-Use black or white text on an orange color band for
liquid ammonia.
5. VAP-Use black or white text on a blue color band for
ammonia vapor.
6. LIQ/VAP-Use both color bands if both states may be
present.
7. Print AMMONIA in black letters on a yellow background.
8. Indicate whether the internal pipe pressure is high or low:
9. HIGH pressure: Use black or white text on a red color band.
10. LOW pressure: Use black or white text on a green
color band.
