Two new IOR guidance notes are now available:


The IOR Technical Committee has published two new guidance notes that will be useful for those working in refrigeration, air conditioning and heat pumps.

The first – Pressure Relief Valve Sizing in Carbon Dioxide Systems (guidance note 40) - was developed as a result of designers, specifiers and end users making the IOR aware that there was some uncertainty around the selection and location of PRV for higher pressure refrigerants in BS EN 13136:2013 the new ISO 24664.  The Guidance will form the basis of ongoing discussion with those responsible for revising these standards.

The second – Quality and Special Processes in RACHP (guidance note 41) – provides general information about the use of quality management and control systems for processes common in the sector such as brazing, that are deemed “special processes” within ISO Quality Management Systems frameworks.  This guidance note explains some of the special processes used within the RACHP industry, what steps should be taken to manage and verify them, and provides additional information as to how this applies specifically to Brazing.

These two publications form part of a series of technical guidance notes produced by the IOR designed to improve safety and raise awareness of best practice and standards in the sector. They are available to download from 

Download the above publications and many more from our technical library.