IIAR 2-2021: Can Hoses Be Permanently Installed in an Ammonia Refrigeration System?

Hoses are used for a variety of purposes in ammonia refrigeration. Often with equipment that is designed to be moved, a corrugated metal hose is used to connect the portable portion of the system to permanent equipment. IIAR standards had been silent on this issue until the recent publication of IIAR Standard 2. ANSI/IIAR 2-2021 §13.2.5 tackled this subject in the following paragraph:

Hoses and corrugated metal fittings used within closed-circuit refrigeration systems shall be designed for permanent installation and meet or exceed the pressure, marking, and manufacturing requirements of ISO 10380 or ARPM IP-14.

While the standard clearly allows hoses to be installed, one must consult ISO 10380 or ARPM IP-14 to understand limitations for installation. ARPM IP-14 Specifications for Anhydrous Ammonia Hose is published by the Association for Rubber Products Manufacturers and costs $325 for non-members to purchase.

ISO 10380 Pipework – Corrugated metal hoses and hose assemblies is an international standard addressing all aspects of corrugated metal hoses. This document never specifically mentions ammonia, but addresses important topics such as:

• Design requirements
• Pressure tests
• Installation instructions

It may be worthwhile to purchase these standards for designers wanting to incorporate permanent hoses into the design of a new system.