Mechanical Integrity in Ammonia Refrigeration Systems Essential for safety, reliability, and productivity!
Mechanical integrity is the cornerstone for safe, reliable, and productive industrial ammonia refrigeration systems. Owners and operators of closed-circuit industrial ammonia refrigeration systems have found it challenging to develop and implement effective mechanical integrity programs for their refrigerated facilities. This is due, in part, to the expansive nature of mechanical integrity itself but also the lack of information and guidance specifically tailored to industrial refrigeration systems and technologies.
Professor Douglas Reindl at the University of Wisconsin-Madison’s Department of Engineering Professional Development and the Industrial Refrigeration Consortium (IRC) prepared the Principles and Practices of Mechanical Integrity Guidebook for Industrial Refrigeration Systems to serve as a comprehensive resource for those involved in designing, constructing, operating, and maintaining closed-circuit industrial ammonia refrigeration systems.
What is mechanical integrity?
Mechanical integrity begins at the “birth” of an ammonia refrigeration system when appropriate quality assurance steps are taken to verify the equipment has been installed properly. A functional mechanical integrity program then drives ongoing inspections, evaluations, tests, calibrations, and maintenance activities to confirm the system can safely operate throughout its life.
One of the biggest threats to the ongoing integrity of an ammonia refrigeration is external corrosion like that shown below. In this case, the exposed piping is exhibiting degradation due to corrosion but the failed insulation system raises further concerns due to its ability to conceal active corrosion under insulation (CUI). This Guidebook provides practical guidance on inspecting and maintaining both uninsulated and insulated piping systems and pressure vessels.
What makes mechanical integrity so important?
The “one of a kind” nature of industrial refrigeration systems and the varied environments where they are installed make it difficult to anticipate every circumstance that can lead to a loss of mechanical integrity. This Guidebook will help you understand mechanisms that contribute to degrading the mechanical integrity of ammonia refrigeration infrastructure and steps you can take to prevent failures that can result in unplanned downtime or uncontrolled refrigerant releases.
Are there regulatory implications?
The mechanical integrity provisions of OSHA’s Process Safety Management standard are among the most frequently cited. Similarly, EPA has also documented a high frequency of non-compliance with the mechanical integrity provisions of the Risk Management Plan program. Although regulatory compliance should not be the prime factor that motivates a facility to pursue a solid mechanical integrity program, successful implementation will provide substantially greater benefits.
The reality
Today, facilities with industrial ammonia refrigeration systems have limited resources and staff, which can result in degraded equipment due to deferred maintenance (as shown in the photos below).
However, with a little inspection and maintenance, this valve group was successfully restored to an as-new condition.
These photos provide a few examples of active external corrosion on piping that, if allowed to persist, will degrade the mechanical integrity of an industrial refrigeration system. The Guidebook provides in-depth coverage of both piping and pressure vessels – including guidance on how to classify external corrosion when it does occur and how to assess piping and pressure vessels to ensure safe continued safe operation.
What kind of equipment is covered in the guidebook?
You will learn about:
- Piping
- Pressure vessels
- Valves
- Heat exchangers
- Compressors
- Pumps
- Safety relief systems
- Ammonia detection systems
- Machinery room safety systems
Where can I learn more about mechanical integrity for industrial ammonia refrigeration systems?
The Guidebook provides recommendations for training and skill development applicable to all personnel involved in mechanical integrity inspections, tests, and equipment maintenance.
In addition, the UW-Madison Department of Engineering Professional Development in collaboration with the IRC offers a course, “Principles and Practices of Mechanical Integrity for Industrial Refrigeration Systems.” Attend this three-day course and use it as a springboard to elevate your mechanical integrity program.