The Natural Refrigeration

Smaller facilities are starting to pay more attention to mechanical integrity, as it remains one of the most cited violation types. Adding to the pressure on facilities to renew focus on mechanical integrity, IIAR 6‑2019: Inspection, Testing, and Maintenance of Closed‑Circuit Ammonia Refrigeration Systems was adopted into the 2024 edition of model codes as the minimum requirement for ITM (Inspection, Testing, and Maintenance) standard for ammonia refrigeration systems, regardless of the system charge.

The standard states that owners must comply once it is adopted by the local authority having jurisdiction, AHJ. So what can facility owners do to make sure their programs are up to speed? Develop and implement a mechanical integrity plan that incorporates the ITMs outlined in IIAR-6, said Doug Reindl, founding Director of the Industrial Refrigeration Consortium.

“For any system built in 2024 or later, the model codes reference IIAR-6 as a requirement,” said Reindl. “And for facilities that are not under PSM, the model code adopted by the AHJ still applies.”

“In cases where we have data on OSHA’s national emphasis program, mechanical integrity is either the number one or number two most cited element year over year. Why? OSHA field inspectors continue to find gaps,” said Reindl.

For most facilities, the factors within mechanical integrity that people miss the most include not having a written program that guides a facility’s mechanical integrity efforts or not doing inspections or tests at specified intervals.

“It’s hard once you get behind because of staff turnovers or transitions, but time keeps moving ahead,” said Reindl. He added that having a plan to keep up with mechanical integrity, for example, by accounting for variation in staff resources, is another way facilities can keep up.

Aside from avoiding regulatory enforcement activity, businesses have a compelling case for focusing on mechanical integrity. “If facilities are diligent about doing inspections and tests and they retire their equipment before it fails, the reliability of their ammonia refrigeration systems improve and that avoids unplanned outages.  Avoiding equipment failure helps protect people on-site, the off-site public, and the environment while delivering continuity in business operations.”

Learning mechanical integrity for ammonia refrigeration systems also makes facility personnel more acutely aware of the warning signs of degradation.

“Facilities should ask . . . what are the specific mechanisms that degrade ammonia refrigeration infrastructure specifically? And they should use that information to do inspections and targeted testing as required and replace that equipment before the end of its life,” said Reindl.

Mechanical integrity as a subject may not get as much focus as other areas, but for facilities, keeping a close eye on it can ensure the business is doing everything it needs to do for the safety of its systems.

Often that starts with simple familiarity and awareness.

“One of the biggest factors that degrades mechanical integrity is the external corrosion of piping and vessels, something that’s easy to see occurring on uninsulated piping and vessels,” said Reindl. “If you see ammonia refrigeration piping or vessels visibly corroding and ignore it, the wall thickness will continue to be reduced and the potential for an uncontrolled release increases.”

“With insulated equipment, corrosion under insulation is a concern so additional techniques are needed to gauge the condition of the piping or vessel,” he said. “A critical part of protecting the [mechanical integrity] of this equipment is ensuring the external surfaces of all insulated piping and vessels are properly coated before insulating.”

Reindl said the last part of the process – following up – is often the easiest to forgo. “Checking in and looking at maintenance over the life of the equipment so you can monitor and truth test to make sure there’s no activity under the insulation, in terms of corrosion, is important.”

IIAR members can access Doug Reindl’s ANR course focused on mechanical integrity via their IIAR member portal.

“One of the main goals for this course is to get attendees to understand the sorts of tests that their routine maintenance requires so they don’t have unplanned failures,” said Reindl. “Particularly those that could cause an unplanned release.”