CORRECTION Made 3/21/2018
So I was glad I was sitting down when I started reading the Public Review #2 Draft of IIAR-6, Standard for Inspection, Testing, and Maintenance of Closed-Circuit Ammonia Refrigeration Systems. Now it’s just a DRAFT version out for public review and comments, but I was so pleased to see TABLE 13.1, Overpressure Protection Devices Inspection, Testing, and Maintenance Tasks state:
“5 and a representative sample replaced and tested annually until bench testing results determine a failure.”
and
c) Bench tested pressure relief valve (PRV) replacement – As determined from bench testing results of a representative sample
Back in September 2014 I wrote a post, Bench Testing your Relief Valves and IIAR, and around the same time IIAR brought up the topic and made their business case for “bench testing” a sampling of RV’s each time to establish an actual data-based frequency rather than using the “at least every five years”. The PUBLIC DRAFT even provides some excellent guidance on how this testing program should be managed. But it is not what it appears!