ANSI/IIAR 2-2021 – Part 1: General | Blog No. 18

If you’re unfamiliar with the International Institute of All-Natural Refrigeration’s (IIAR) flagship standard, then this short blog series will serve as a great primer for you. The 2021 edition has 4 parts which will be summarized in this series, starting with part 1 in this article.

Chapter 1: Purpose, Scope, and Applicability

This standard specifies minimum requirements for the design of safe closed-circuit ammonia refrigeration systems, specifically for stationary closed-circuit vapor compression and absorption refrigeration systems using anhydrous ammonia as the refrigerant. The standard does not apply to replacement in-kind or equipment, systems, and buildings/facilities that existed prior to the legal effective date of the standard, which must remain in accordance with the codes and standards applicable at the time of installation. In cases of conflict with building, fire, mechanical, or electrical codes, the requirements of those codes take precedence unless otherwise stated. Alternative materials and methods may be used if approved by the Authority Having Jurisdiction (AHJ) and shown to be equivalent in quality, strength, effectiveness, durability, and safety. In locations without an AHJ, the designer, who must be a licensed engineering professional, is authorized to approve alternative means and methods of compliance with the standard. Additionally, the licensed engineering professional may approve means and methods listed in the standard that would normally require approval by the AHJ.

Chapter 2: Definitions

Chapter 2 of the ANSI/IIAR-1 standard provides definitions for various terms used in the document. These include terms such as absorption refrigeration system, flammable liquid, limited charge system, heat exchanger, surge drum, and machinery room, among others. The chapter also defines terms related to pressure vessels, car seals, and hydrostatic pressure relief valves. Each definition is intended to provide clarity and understanding of the terminology used within the standard.

Chapter 3: Reference Standards

Chapter 3 of the text discusses various reference standards from different organizations. The American Society of Mechanical Engineers (ASME) standards cover a range of topics including boiler and pressure vessel code, pipe flanges, forged fittings, metallic and nonmetallic gaskets, refrigeration piping, and heat transfer components. The American Society of Testing and Materials (ASTM) provides standards for pipe specifications and malleable iron. The UAR standards from the ANSI/IIAR, ANSVIIAR, and ANSI/UAR focus on definitions used in standards, inspection, testing, and maintenance of closed-circuit ammonia refrigeration systems, and safety requirements for existing closed-circuit ammonia refrigeration systems. Other standards from organizations such as the International Safety Equipment Association (ISEA), National Fire Protection Association (NFPA), Occupational Safety and Health Administration (OSHA), ASHRAE, United States National Institute of Standards and Technology (NIST), UL, LLC, International Organization for Standardization (ISO), Association for Rubber Products Manufacturers, and International Society of Automation (ISA) cover topics such as emergency eyewash and shower equipment, national electrical code, identification of hazardous materials, safety requirements for electrical equipment, designations and safety classification of refrigerants, the international system of units, safety requirements for pipework, specifications for ammonia hose, and performance requirements for toxic gas detectors.